use has_* naming

use the conditional
Fix FTDUI Status Screen Timeout
2022-10-21 16:39:33 -05:00 · 2022-10-19 21:09:43 -05:00 · 2022-10-18 17:53:07 -04:00 · 2022-10-17 23:00:26 -05:00 · 2022-10-17 22:47:09 -05:00 · 2022-10-17 22:41:41 -05:00
1152 changed files with 47124 additions and 29334 deletions
@@ -14,6 +14,10 @@ end_of_line = lf
 indent_style = space
 indent_size = 2

-[{*.py,*.conf,*.sublime-project}]
+[{*.py}]
+indent_style = space
+indent_size = 4
+
+[{*.conf,*.sublime-project}]
 indent_style = tab
 indent_size = 4
@@ -0,0 +1,178 @@
+name: 🪲 Report a bug
+description: Create a bug report to help improve Marlin Firmware
+title: "[BUG] (bug summary)"
+body:
+  - type: markdown
+    attributes:
+      value: >
+        Do you want to ask a question? Are you looking for support? Please use one of the [support links](https://github.com/MarlinFirmware/Marlin/issues/new/choose).
+
+  - type: markdown
+    attributes:
+      value: |
+        **Thank you for reporting a bug in Marlin Firmware!**
+
+        ## Before Reporting a Bug
+
+        - Read and understand Marlin's [Code of Conduct](https://github.com/MarlinFirmware/Marlin/blob/bugfix-2.1.x/.github/code_of_conduct.md). You are expected to comply with it, including treating everyone with respect.
+
+        - Test with the [`bugfix-2.1.x` branch](https://github.com/MarlinFirmware/Marlin/archive/bugfix-2.1.x.zip) to see whether the issue still exists.
+
+        ## Instructions
+
+        Please follow the instructions below. Failure to do so may result in your issue being closed. See [Contributing to Marlin](https://github.com/MarlinFirmware/Marlin/blob/bugfix-2.1.x/.github/contributing.md) for additional guidelines.
+
+        1. Provide a good title starting with [BUG].
+        2. Fill out all sections of this bug report form.
+        3. Always attach configuration files so we can build and test your setup.
+
+  - type: dropdown
+    attributes:
+      label: Did you test the latest `bugfix-2.1.x` code?
+      description: >-
+        Always try the latest code to make sure the issue you are reporting is not already fixed. To download
+        the latest code just [click this link](https://github.com/MarlinFirmware/Marlin/archive/bugfix-2.1.x.zip).
+      options:
+        - Yes, and the problem still exists.
+        - No, but I will test it now!
+    validations:
+      required: true
+
+  - type: markdown
+    attributes:
+      value: |
+        # Bug Details
+
+  - type: textarea
+    attributes:
+      label: Bug Description
+      description: >-
+        Describe the bug in this section. Tell us what you were trying to do and what
+        happened that you did not expect. Provide a clear and concise description of the
+        problem and include as many details as possible.
+
+        When pasting formatted text don't forget to put ` ``` ` (on its own line) before and after to make it readable.
+      placeholder: |
+        Marlin doesn't work.
+    validations:
+      required: true
+
+  - type: input
+    attributes:
+      label: Bug Timeline
+      description: Is this a new bug or an old issue? When did it first start?
+
+  - type: textarea
+    attributes:
+      label: Expected behavior
+      description: >-
+        What did you expect to happen?
+      placeholder: I expected it to move left.
+
+  - type: textarea
+    attributes:
+      label: Actual behavior
+      description: What actually happened instead?
+      placeholder: It moved right instead of left.
+
+  - type: textarea
+    attributes:
+      label: Steps to Reproduce
+      description: >-
+        Please describe the steps needed to reproduce the issue.
+      placeholder: |
+        1. [First Step] ...
+        2. [Second Step] ...
+        3. [and so on] ...
+
+  - type: markdown
+    attributes:
+      value: |
+        # Your Setup
+
+  - type: input
+    attributes:
+      label: Version of Marlin Firmware
+      description: "See the About Menu on the LCD or the output of `M115`. NOTE: For older releases we only patch critical bugs."
+    validations:
+      required: true
+
+  - type: input
+    attributes:
+      label: Printer model
+      description: Creality Ender 3, Prusa mini, or Kossel Delta?
+
+  - type: input
+    attributes:
+      label: Electronics
+      description: Stock electronics, upgrade board, or something else?
+
+  - type: input
+    attributes:
+      label: Add-ons
+      description: Please list any hardware add-ons that could be involved.
+
+  - type: dropdown
+    attributes:
+      label: Bed Leveling
+      description: What kind of bed leveling compensation are you using?
+      options:
+        - UBL Bilinear mesh
+        - ABL Bilinear mesh
+        - ABL Linear grid
+        - ABL 3-point
+        - MBL Manual Bed Leveling
+        - No Bed Leveling
+
+  - type: dropdown
+    attributes:
+      label: Your Slicer
+      description: Do you use Slic3r, Prusa Slicer, Simplify3D, IdeaMaker...?
+      options:
+        - Slic3r
+        - Simplify3D
+        - Prusa Slicer
+        - IdeaMaker
+        - Cura
+        - Other (explain below)
+
+  - type: dropdown
+    attributes:
+      label: Host Software
+      description: Do you use OctoPrint, Repetier Host, Pronterface...?
+      options:
+        - SD Card (headless)
+        - Repetier Host
+        - OctoPrint
+        - Pronterface
+        - Cura
+        - Same as my slicer
+        - Other (explain below)
+
+  - type: markdown
+    attributes:
+      value: |
+        # Attachments
+
+  - type: checkboxes
+    attributes:
+      label: Don't forget to include
+      options:
+        - label: A ZIP file containing your `Configuration.h` and `Configuration_adv.h`.
+          required: true
+
+  - type: markdown
+    attributes:
+      value: |
+        ### Optional items to include:
+        - 'Log output from the host. (`M111 S247` for maximum logging.)'
+        - Images or videos demonstrating the problem, if it helps to make it clear.
+        - A G-Code file that exposes the problem, if not affecting _all_ G-code.
+
+  - type: textarea
+    attributes:
+      label: Additional information & file uploads
+      description: >-
+        If you've made any other modifications to the firmware, please describe them in detail.
+
+        When pasting formatted text don't forget to put ` ``` ` (on its own line) before and after to make it readable.
@@ -0,0 +1,20 @@
+blank_issues_enabled: false
+contact_links:
+  - name: 📖 Marlin Documentation
+    url: https://marlinfw.org/
+    about: Lots of documentation on installing and using Marlin.
+  - name: 👤 MarlinFirmware Facebook group
+    url: https://www.facebook.com/groups/1049718498464482
+    about: Please ask and answer questions here.
+  - name: 🕹 Marlin on Discord
+    url: https://discord.gg/n5NJ59y
+    about: Join the Discord server for support and discussion.
+  - name: 🔗 Marlin Discussion Forum
+    url: https://reprap.org/forum/list.php?415
+    about: A searchable web forum hosted by RepRap dot org.
+  - name: 📺 Marlin Videos on YouTube
+    url: https://www.youtube.com/results?search_query=marlin+firmware
+    about: Tutorials and more from Marlin users all around the world. Great for new users!
+  - name: 💸 Want to donate?
+    url: https://www.thinkyhead.com/donate-to-marlin
+    about: Please take a look at the various options to support Marlin Firmware's development financially!
@@ -0,0 +1,44 @@
+name: ✨ Request a feature
+description: Request a new Marlin Firmware feature
+title: "[FR] (feature summary)"
+labels: 'T: Feature Request'
+body:
+  - type: markdown
+    attributes:
+      value: >
+        Do you want to ask a question? Are you looking for support? Please use one of the [support links](https://github.com/MarlinFirmware/Marlin/issues/new/choose).
+
+  - type: markdown
+    attributes:
+      value: >
+        **Thank you for requesting a new Marlin Firmware feature!**
+
+        ## Before Requesting a Feature
+
+        - Read and understand Marlin's [Code of Conduct](https://github.com/MarlinFirmware/Marlin/blob/master/.github/code_of_conduct.md). You are expected to comply with it, including treating everyone with respect.
+
+        - Check the latest [`bugfix-2.1.x` branch](https://github.com/MarlinFirmware/Marlin/archive/bugfix-2.1.x.zip) to see if the feature already exists.
+
+        - Before you proceed with your request, please consider if it is necessary to make it into a firmware feature, or if it may be better suited for a slicer or host feature.
+
+  - type: textarea
+    attributes:
+      label: Is your feature request related to a problem? Please describe.
+      description: A clear description of the problem (e.g., "I need X but Marlin can't do it [...]").
+
+  - type: textarea
+    attributes:
+      label: Are you looking for hardware support?
+      description: Tell us the printer, board, or peripheral that needs support.
+
+  - type: textarea
+    attributes:
+      label: Describe the feature you want
+      description: A clear description of the feature and how you think it should work.
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Additional context
+      description: Add any other context or screenshots about the feature request here.
@@ -34,8 +34,11 @@ This project and everyone participating in it is governed by the [Marlin Code of

 We have a Message Board and a Facebook group where our knowledgable user community can provide helpful advice if you have questions.

-* [Marlin RepRap forum](https://reprap.org/forum/list.php?415)
-* [MarlinFirmware on Facebook](https://www.facebook.com/groups/1049718498464482/)
+- [Marlin Documentation](https://marlinfw.org) - Official Marlin documentation
+- Facebook Group ["Marlin Firmware"](https://www.facebook.com/groups/1049718498464482/)
+- RepRap.org [Marlin Forum](https://forums.reprap.org/list.php?415)
+- Facebook Group ["Marlin Firmware for 3D Printers"](https://www.facebook.com/groups/3Dtechtalk/)
+- [Marlin Configuration](https://www.youtube.com/results?search_query=marlin+configuration) on YouTube

 If chat is more your speed, you can join the MarlinFirmware Discord server:

@@ -50,13 +53,13 @@ If chat is more your speed, you can join the MarlinFirmware Discord server:

 This section guides you through submitting a Bug Report for Marlin. Following these guidelines helps maintainers and the community understand your report, reproduce the behavior, and find related reports.

-Before creating a Bug Report, please test the "nightly" development branch, as you might find out that you don't need to create one. When you are creating a Bug Report, please [include as many details as possible](#how-do-i-submit-a-good-bug-report). Fill out [the required template](issue_template.md), the information it asks for helps us resolve issues faster.
+Before creating a Bug Report, please test the "nightly" development branch, as you might find out that you don't need to create one. When you are creating a Bug Report, please [include as many details as possible](#how-do-i-submit-a-good-bug-report). Fill out [the required template](ISSUE_TEMPLATE/bug_report.yml), the information it asks for helps us resolve issues faster.

 > **Note:** Regressions can happen. If you find a **Closed** issue that seems like your issue, go ahead and open a new issue and include a link to the original issue in the body of your new one. All you need to create a link is the issue number, preceded by #. For example, #8888.

 #### How Do I Submit A (Good) Bug Report?

-Bugs are tracked as [GitHub issues](https://guides.github.com/features/issues/). Use the New Issue button to create an issue and provide the following information by filling in [the template](issue_template.md).
+Bugs are tracked as [GitHub issues](https://guides.github.com/features/issues/). Use the New Issue button to create an issue and provide the following information by filling in [the template](ISSUE_TEMPLATE/bug_report.yml).

 Explain the problem and include additional details to help maintainers reproduce the problem:

@@ -88,12 +91,12 @@ Include details about your configuration and environment:

 This section guides you through submitting a suggestion for Marlin, including completely new features and minor improvements to existing functionality. Following these guidelines helps maintainers and the community understand your suggestion and find related suggestions.

-Before creating a suggestion, please check [this list](#before-submitting-a-suggestion) as you might find out that you don't need to create one. When you are creating an enhancement suggestion, please [include as many details as possible](#how-do-i-submit-a-good-enhancement-suggestion). Fill in [the template](issue_template.md), including the steps that you imagine you would take if the feature you're requesting existed.
+Before creating a suggestion, please check [this list](https://github.com/MarlinFirmware/Marlin/issues?q=is%3Aopen+is%3Aissue+label%3A%22T%3A+Feature+Request%22) as you might find out that you don't need to create one. When you are creating an enhancement suggestion, please [include as many details as possible](#how-do-i-submit-a-good-feature-request). Fill in [the template](ISSUE_TEMPLATE/feature_request.yml), including the steps that you imagine you would take if the feature you're requesting existed.

 #### Before Submitting a Feature Request

 * **Check the [Marlin website](https://marlinfw.org/)** for tips — you might discover that the feature is already included. Most importantly, check if you're using [the latest version of Marlin](https://github.com/MarlinFirmware/Marlin/releases) and if you can get the desired behavior by changing [Marlin's config settings](https://marlinfw.org/docs/configuration/configuration.html).
-* **Perform a [cursory search](https://github.com/MarlinFirmware/Marlin/issues?q=is%3Aissue)** to see if the enhancement has already been suggested. If it has, add a comment to the existing issue instead of opening a new one.
+* **Perform a [cursory search](https://github.com/MarlinFirmware/Marlin/issues?q=is%3Aopen+is%3Aissue+label%3A%22T%3A+Feature+Request%22)** to see if the enhancement has already been suggested. If it has, add a comment to the existing issue instead of opening a new one.

 #### How Do I Submit A (Good) Feature Request?

@@ -116,7 +119,7 @@ Unsure where to begin contributing to Marlin? You can start by looking through t

 ### Pull Requests

-Pull Requests should always be targeted to working branches (e.g., `bugfix-1.1.x` and/or `bugfix-2.0.x`) and never to release branches (e.g., `1.1.x`). If this is your first Pull Request, please read our [Guide to Pull Requests](https://marlinfw.org/docs/development/getting_started_pull_requests.html) and Github's [Pull Request](https://help.github.com/articles/creating-a-pull-request/) documentation.
+Pull Requests should always be targeted to working branches (e.g., `bugfix-2.1.x` and/or `bugfix-1.1.x`) and never to release branches (e.g., `2.0.x` and/or `1.1.x`). If this is your first Pull Request, please read our [Guide to Pull Requests](https://marlinfw.org/docs/development/getting_started_pull_requests.html) and Github's [Pull Request](https://help.github.com/articles/creating-a-pull-request/) documentation.

 * Fill in [the required template](pull_request_template.md).
 * Don't include issue numbers in the PR title.
@@ -1,35 +0,0 @@
-<!--
-
-Have you read Marlin's Code of Conduct? By filing an Issue, you are expected to comply with it, including treating everyone with respect: https://github.com/MarlinFirmware/Marlin/blob/bugfix-2.0.x/.github/code_of_conduct.md
-
-Do you want to ask a question? Are you looking for support? Please don't post here. Instead use one of the following options:
-
- The Marlin Firmware forum at https://reprap.org/forum/list.php?415
- The MarlinFirmware Facebook Group at https://www.facebook.com/groups/1049718498464482/
- The MarlinFirmware Discord Server at https://discord.gg/n5NJ59y.
-
-Before filing an issue be sure to test the latest "bugfix" branch to see whether the issue is already addressed.
-
-->
-
-### Description
-
-<!-- Description of the bug or requested feature -->
-
-### Steps to Reproduce
-
-<!-- If this is a Bug Report, please describe the steps needed to reproduce the issue -->
-
-1. [First Step]
-2. [Second Step]
-3. [and so on...]
-
-**Expected behavior:** [What you expect to happen]
-
-**Actual behavior:** [What actually happens]
-
-#### Additional Information
-
-* Include a ZIP file containing your `Configuration.h` and `Configuration_adv.h` files.
-* Provide pictures or links to videos that clearly demonstrate the issue.
-* See [How Can I Contribute](#how-can-i-contribute) for additional guidelines.
@@ -1,23 +1,33 @@
-### Requirements
+<!--

-* Filling out this template is required. Pull Requests without a clear description may be closed at the maintainers' discretion.
+Submitting a Pull Request
+
+- Please fill out all sections of this form. You can delete the helpful comments.
+- Pull Requests without clear information will take longer and may even be rejected.
+- We get a high volume of submissions so please be patient during review.
+
+-->

 ### Description

 <!--

-We must be able to understand your proposed change from this description. If we can't understand what the code will do from this description, the Pull Request may be closed at the maintainers' discretion. Keep in mind that the maintainer reviewing this PR may not be familiar with or have worked with the code recently, so please walk us through the concepts.
+Clearly describe the submitted changes with lots of details. Include images where helpful. Initial reviewers may not be familiar with the subject, so be as thorough as possible. You can use MarkDown syntax to improve readability with bullet lists, code blocks, and so on. PREVIEW and fix up formatting before submitting.

 -->

+### Requirements
+
+<!-- Does this PR require a specific board, LCD, etc.? -->
+
 ### Benefits

-<!-- What does this fix or improve? -->
+<!-- What does this PR fix or improve? -->

 ### Configurations

-<!-- Attach any Configuration.h, Configuration_adv.h, or platformio.ini files needed to compile/test your Pull Request. -->
+<!-- Attach Configurations ZIP and any other files needed to test this PR. -->

 ### Related Issues

-<!-- Whether this fixes a bug or fulfills a feature request, please list any related Issues here. -->
+<!-- Does this PR fix a bug or fulfill a Feature Request? Link related Issues here. -->
@@ -0,0 +1,59 @@
+#
+# bump-date.yml
+# Bump the distribution date once per day
+#
+
+name: Bump Distribution Date
+
+on:
+  schedule:
+    - cron: '0 */6 * * *'
+
+jobs:
+  bump_date:
+    name: Bump Distribution Date
+    if: github.repository == 'MarlinFirmware/Marlin'
+
+    runs-on: ubuntu-latest
+
+    steps:
+
+    - name: Check out bugfix-2.1.x
+      uses: actions/checkout@v2
+      with:
+        ref: bugfix-2.1.x
+
+    - name: Bump Date (bugfix-2.0.x)
+      run: |
+        # Inline Bump Script
+        if [[ ! "$( git log -1 --pretty=%B )" =~ ^\[cron\] ]]; then
+          DIST=$( date +"%Y-%m-%d" )
+          eval "sed -E -i 's/(#define +STRING_DISTRIBUTION_DATE) .*$/\1 \"$DIST\"/g' Marlin/src/inc/Version.h" && \
+          eval "sed -E -i 's/(#define +STRING_DISTRIBUTION_DATE) .*$/\1 \"$DIST\"/g' Marlin/Version.h" && \
+          git config user.name "${GITHUB_ACTOR}" && \
+          git config user.email "${GITHUB_ACTOR}@users.noreply.github.com" && \
+          git add . && \
+          git commit -m "[cron] Bump distribution date ($DIST)" && \
+          git push
+        fi
+        exit 0
+
+    - name: Check out bugfix-2.1.x
+      uses: actions/checkout@v2
+      with:
+        ref: bugfix-2.1.x
+
+    - name: Bump Date (bugfix-2.1.x)
+      run: |
+        # Inline Bump Script
+        if [[ ! "$( git log -1 --pretty=%B )" =~ ^\[cron\] ]]; then
+          DIST=$( date +"%Y-%m-%d" )
+          eval "sed -E -i 's/(#define +STRING_DISTRIBUTION_DATE) .*$/\1 \"$DIST\"/g' Marlin/src/inc/Version.h" && \
+          eval "sed -E -i 's/(#define +STRING_DISTRIBUTION_DATE) .*$/\1 \"$DIST\"/g' Marlin/Version.h" && \
+          git config user.name "${GITHUB_ACTOR}" && \
+          git config user.email "${GITHUB_ACTOR}@users.noreply.github.com" && \
+          git add . && \
+          git commit -m "[cron] Bump distribution date ($DIST)" && \
+          git push
+        fi
+        exit 0
@@ -0,0 +1,34 @@
+#
+# check-pr.yml
+# Close PRs directed at release branches
+#
+
+name: PR Bad Target
+
+on:
+  pull_request_target:
+    types: [opened]
+    branches:
+    - 1.0.x
+    - 1.1.x
+    - 2.0.x
+    - 2.1.x
+
+jobs:
+  bad_target:
+    name: PR Bad Target
+    if: github.repository == 'MarlinFirmware/Marlin'
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: superbrothers/close-pull-request@v3
+      with:
+        comment: >
+          Thanks for your contribution! Unfortunately we can't accept PRs directed at release branches. We make patches to the bugfix branches and only later do we push them out as releases.
+
+          Please redo this PR starting with the `bugfix-2.1.x` branch and be careful to target `bugfix-2.1.x` when resubmitting the PR. Patches may also target `bugfix-2.0.x` if they are specifically for 2.0.9.x.
+
+          It may help to set your fork's default branch to `bugfix-2.0.x`.
+
+          See [this page](https://marlinfw.org/docs/development/getting_started_pull_requests.html) for full instructions.
@@ -0,0 +1,39 @@
+#
+# clean-closed.yml
+# Remove obsolete labels when an Issue or PR is closed
+#
+
+name: Clean Closed
+
+on:
+  pull_request:
+    types: [closed]
+  issues:
+    types: [closed]
+
+jobs:
+  remove_label:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        label:
+          - "S: Don't Merge"
+          - "S: Hold for 2.1"
+          - "S: Please Merge"
+          - "S: Please Test"
+          - "help wanted"
+          - "Needs: Discussion"
+          - "Needs: Documentation"
+          - "Needs: More Data"
+          - "Needs: Patch"
+          - "Needs: Testing"
+          - "Needs: Work"
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Remove Labels
+        uses: actions-ecosystem/action-remove-labels@v1
+        with:
+          github_token: ${{ github.token }}
+          labels: ${{ matrix.label }}
@@ -0,0 +1,28 @@
+#
+# close-stale.yml
+# Close open issues after a period of inactivity
+#
+
+name: Close Stale Issues
+
+on:
+  schedule:
+  - cron: "22 1 * * *"
+
+jobs:
+  stale:
+    name: Close Stale Issues
+    if: github.repository == 'MarlinFirmware/Marlin'
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/stale@v3
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        stale-issue-message: 'This issue has had no activity in the last 60 days. Please add a reply if you want to keep this issue active, otherwise it will be automatically closed within 10 days.'
+        days-before-stale: 60
+        days-before-close: 10
+        stale-issue-label: 'stale-closing-soon'
+        exempt-all-assignees: true
+        exempt-issue-labels: 'Bug: Confirmed !,T: Feature Request,Needs: More Data,Needs: Discussion,Needs: Documentation,Needs: Patch,Needs: Work,Needs: Testing,help wanted,no-locking'
@@ -0,0 +1,32 @@
+#
+# lock-closed.yml
+# Lock closed issues after a period of inactivity
+#
+
+name: Lock Closed Issues
+
+on:
+  schedule:
+    - cron: '0 1/13 * * *'
+
+jobs:
+  lock:
+    name: Lock Closed Issues
+    if: github.repository == 'MarlinFirmware/Marlin'
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: dessant/lock-threads@v2
+      with:
+        github-token: ${{ github.token }}
+        process-only: 'issues'
+        issue-lock-inactive-days: '60'
+        issue-exclude-created-before: ''
+        issue-exclude-labels: 'no-locking'
+        issue-lock-labels: ''
+        issue-lock-comment: >
+          This issue has been automatically locked since there
+          has not been any recent activity after it was closed.
+          Please open a new issue for related bugs.
+        issue-lock-reason: ''
@@ -8,7 +8,7 @@ name: CI
 on:
  pull_request:
    branches:
-    - bugfix-2.0.x
+    - bugfix-2.1.x
    paths-ignore:
    - config/**
    - data/**
@@ -16,7 +16,7 @@ on:
    - '**/*.md'
  push:
    branches:
-    - bugfix-2.0.x
+    - bugfix-2.1.x
    paths-ignore:
    - config/**
    - data/**
@@ -45,6 +45,7 @@ jobs:
        - teensy35
        - teensy41
        - SAMD51_grandcentral_m4
+        - PANDA_PI_V29

        # Extended AVR Environments

@@ -59,13 +60,13 @@ jobs:
        #- STM32F103RC_btt_maple
        - STM32F103RC_btt_USB_maple
        - STM32F103RC_fysetc_maple
-        - STM32F103RC_meeb
+        - STM32F103RC_meeb_maple
        - jgaurora_a5s_a1_maple
        - STM32F103VE_longer_maple
        #- mks_robin_maple
        - mks_robin_lite_maple
        - mks_robin_pro_maple
-        #- mks_robin_nano35_maple
+        #- mks_robin_nano_v1v2_maple
        #- STM32F103RE_creality_maple
        - STM32F103VE_ZM3E4V2_USB_maple

@@ -76,9 +77,9 @@ jobs:
        - STM32F103RE_btt
        - STM32F103RE_btt_USB
        - STM32F103RE_creality
+        - STM32F401RC_creality
        - STM32F103VE_longer
        - STM32F407VE_black
-        - STM32F401VE_STEVAL
        - BIGTREE_BTT002
        - BIGTREE_SKR_PRO
        - BIGTREE_GTR_V1_0
@@ -92,12 +93,17 @@ jobs:
        - rumba32
        - LERDGEX
        - LERDGEK
-        - mks_robin_nano35
+        - mks_robin_nano_v1v2
+        #- mks_robin_nano_v1v2_usbmod
+        #- mks_robin_nano_v1_3_f4_usbmod
        - NUCLEO_F767ZI
        - REMRAM_V1
        - BTT_SKR_SE_BX
        - chitu_f103
-        - Index_Mobo_Rev03
+        - Opulo_Lumen_REV3
+
+        # ESP32 environments
+        - mks_tinybee

        # Put lengthy tests last

@@ -113,10 +119,10 @@ jobs:
    steps:

    - name: Check out the PR
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3

    - name: Cache pip
-      uses: actions/cache@v2
+      uses: actions/cache@v3
      with:
        path: ~/.cache/pip
        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
@@ -124,21 +130,22 @@ jobs:
          ${{ runner.os }}-pip-

    - name: Cache PlatformIO
-      uses: actions/cache@v2
+      uses: actions/cache@v3
      with:
        path: ~/.platformio
        key: ${{ runner.os }}-${{ hashFiles('**/lockfiles') }}

    - name: Select Python 3.7
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
      with:
        python-version: '3.7' # Version range or exact version of a Python version to use, using semvers version range syntax.
        architecture: 'x64' # optional x64 or x86. Defaults to x64 if not specified

    - name: Install PlatformIO
      run: |
-        pip install -U https://github.com/platformio/platformio-core/archive/develop.zip
-        platformio update
+        pip install -U platformio
+        pio upgrade --dev
+        pio pkg update --global

    - name: Run ${{ matrix.test-platform }} Tests
      run: |
@@ -0,0 +1,22 @@
+#
+# unlock-reopened.yml
+# Unlock an issue whenever it is re-opened
+#
+
+name: "Unlock reopened issue"
+
+on:
+  issues:
+    types: [reopened]
+
+jobs:
+  unlock:
+    name: Unlock Reopened
+    if: github.repository == 'MarlinFirmware/Marlin'
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: OSDKDev/unlock-issues@v1.1
+      with:
+        repo-token: "${{ secrets.GITHUB_TOKEN }}"
@@ -147,6 +147,7 @@ vc-fileutils.settings
 imgui.ini
 eeprom.dat
 spi_flash.bin
+fs.img

 #cmake
 CMakeLists.txt
@@ -4,5 +4,8 @@
    "recommendations": [
        "marlinfirmware.auto-build",
        "platformio.platformio-ide"
+    ],
+    "unwantedRecommendations": [
+        "ms-vscode.cpptools-extension-pack"
    ]
 }
@@ -27,7 +27,7 @@ tests-single-ci:

 tests-single-local:
 	@if ! test -n "$(TEST_TARGET)" ; then echo "***ERROR*** Set TEST_TARGET=<your-module> or use make tests-all-local" ; return 1; fi
-	export PATH=./buildroot/bin/:./buildroot/tests/:${PATH} \
+	export PATH="./buildroot/bin/:./buildroot/tests/:${PATH}" \
 	  && export VERBOSE_PLATFORMIO=$(VERBOSE_PLATFORMIO) \
 	  && run_tests . $(TEST_TARGET) "$(ONLY_TEST)"
 .PHONY: tests-single-local
@@ -38,7 +38,7 @@ tests-single-local-docker:
 .PHONY: tests-single-local-docker

 tests-all-local:
-	export PATH=./buildroot/bin/:./buildroot/tests/:${PATH} \
+	export PATH="./buildroot/bin/:./buildroot/tests/:${PATH}" \
 	  && export VERBOSE_PLATFORMIO=$(VERBOSE_PLATFORMIO) \
 	  && for TEST_TARGET in $$(./get_test_targets.py) ; do echo "Running tests for $$TEST_TARGET" ; run_tests . $$TEST_TARGET ; done
 .PHONY: tests-all-local
@@ -109,7 +109,7 @@ LIQUID_TWI2        ?= 0
 # This defines if Wire is needed
 WIRE               ?= 0

-# This defines if Tone is needed (i.e SPEAKER is defined in Configuration.h)
+# This defines if Tone is needed (i.e., SPEAKER is defined in Configuration.h)
 # Disabling this (and SPEAKER) saves approximately 350 bytes of memory.
 TONE               ?= 1

@@ -132,7 +132,7 @@ CC_MIN:=$(shell $(CC) -dM -E - < /dev/null | grep __GNUC_MINOR__ | cut -f3 -d\ )
 CC_PATCHLEVEL:=$(shell $(CC) -dM -E - < /dev/null | grep __GNUC_PATCHLEVEL__ | cut -f3 -d\ )
 CC_VER:=$(shell echo $$(( $(CC_MAJ) * 10000 + $(CC_MIN) * 100 + $(CC_PATCHLEVEL) )))
 ifeq ($(shell test $(CC_VER) -lt 40901 && echo 1),1)
-  @echo This version of GCC is likely broken. Enabling relocation workaround.
+  $(warning This GCC version $(CC_VER) is likely broken. Enabling relocation workaround.)
  RELOC_WORKAROUND = 1
 endif

@@ -317,123 +317,10 @@ else ifeq ($(HARDWARE_MOTHERBOARD),1159)
 else ifeq ($(HARDWARE_MOTHERBOARD),1160)
 # Longer LKx PRO / Alfawise Uxx Pro (PRO version)
 else ifeq ($(HARDWARE_MOTHERBOARD),1161)
-
-
-# 3Drag Controller
-else ifeq ($(HARDWARE_MOTHERBOARD),1100)
-# Velleman K8200 Controller (derived from 3Drag Controller)
-else ifeq ($(HARDWARE_MOTHERBOARD),1101)
-# Velleman K8400 Controller (derived from 3Drag Controller)
-else ifeq ($(HARDWARE_MOTHERBOARD),1102)
-# Velleman K8600 Controller (Vertex Nano)
-else ifeq ($(HARDWARE_MOTHERBOARD),1103)
-# Velleman K8800 Controller (Vertex Delta)
-else ifeq ($(HARDWARE_MOTHERBOARD),1104)
-# 2PrintBeta BAM&DICE with STK drivers
-else ifeq ($(HARDWARE_MOTHERBOARD),1105)
-# 2PrintBeta BAM&DICE Due with STK drivers
-else ifeq ($(HARDWARE_MOTHERBOARD),1106)
-# MKS BASE v1.0
-else ifeq ($(HARDWARE_MOTHERBOARD),1107)
-# MKS v1.4 with A4982 stepper drivers
-else ifeq ($(HARDWARE_MOTHERBOARD),1108)
-# MKS v1.5 with Allegro A4982 stepper drivers
-else ifeq ($(HARDWARE_MOTHERBOARD),1109)
-# MKS v1.6 with Allegro A4982 stepper drivers
-else ifeq ($(HARDWARE_MOTHERBOARD),1110)
-# MKS BASE 1.0 with Heroic HR4982 stepper drivers
-else ifeq ($(HARDWARE_MOTHERBOARD),1111)
-# MKS GEN v1.3 or 1.4
-else ifeq ($(HARDWARE_MOTHERBOARD),1112)
-# MKS GEN L
-else ifeq ($(HARDWARE_MOTHERBOARD),1113)
-# zrib V2.0 control board (Chinese RAMPS replica)
-else ifeq ($(HARDWARE_MOTHERBOARD),1114)
-# BigTreeTech or BIQU KFB2.0
-else ifeq ($(HARDWARE_MOTHERBOARD),1115)
-# Felix 2.0+ Electronics Board (RAMPS like)
-else ifeq ($(HARDWARE_MOTHERBOARD),1116)
-# Invent-A-Part RigidBoard
-else ifeq ($(HARDWARE_MOTHERBOARD),1117)
-# Invent-A-Part RigidBoard V2
-else ifeq ($(HARDWARE_MOTHERBOARD),1118)
-# Sainsmart 2-in-1 board
-else ifeq ($(HARDWARE_MOTHERBOARD),1119)
-# Ultimaker
-else ifeq ($(HARDWARE_MOTHERBOARD),1120)
-# Ultimaker (Older electronics. Pre 1.5.4. This is rare)
-else ifeq ($(HARDWARE_MOTHERBOARD),1121)
-  MCU              ?= atmega1280
-  PROG_MCU         ?= m1280
-
-# Azteeg X3
-else ifeq ($(HARDWARE_MOTHERBOARD),1122)
-# Azteeg X3 Pro
-else ifeq ($(HARDWARE_MOTHERBOARD),1123)
-# Ultimainboard 2.x (Uses TEMP_SENSOR 20)
-else ifeq ($(HARDWARE_MOTHERBOARD),1124)
-# Rumba
-else ifeq ($(HARDWARE_MOTHERBOARD),1125)
-# Raise3D Rumba
-else ifeq ($(HARDWARE_MOTHERBOARD),1126)
-# Rapide Lite RL200 Rumba
-else ifeq ($(HARDWARE_MOTHERBOARD),1127)
-# Formbot T-Rex 2 Plus
-else ifeq ($(HARDWARE_MOTHERBOARD),1128)
-# Formbot T-Rex 3
-else ifeq ($(HARDWARE_MOTHERBOARD),1129)
-# Formbot Raptor
-else ifeq ($(HARDWARE_MOTHERBOARD),1130)
-# Formbot Raptor 2
-else ifeq ($(HARDWARE_MOTHERBOARD),1131)
-# bq ZUM Mega 3D
-else ifeq ($(HARDWARE_MOTHERBOARD),1132)
-# MakeBoard Mini v2.1.2 is a control board sold by MicroMake
-else ifeq ($(HARDWARE_MOTHERBOARD),1133)
-# TriGorilla Anycubic version 1.3 based on RAMPS EFB
-else ifeq ($(HARDWARE_MOTHERBOARD),1134)
-# TriGorilla Anycubic version 1.4 based on RAMPS EFB
-else ifeq ($(HARDWARE_MOTHERBOARD),1135)
-# TriGorilla Anycubic version 1.4 Rev 1.1
-else ifeq ($(HARDWARE_MOTHERBOARD),1136)
-# Creality: Ender-4, CR-8
-else ifeq ($(HARDWARE_MOTHERBOARD),1137)
-# Creality: CR10S, CR20, CR-X
-else ifeq ($(HARDWARE_MOTHERBOARD),1138)
-# Dagoma F5
-else ifeq ($(HARDWARE_MOTHERBOARD),1139)
-# FYSETC F6 1.3
-else ifeq ($(HARDWARE_MOTHERBOARD),1140)
-# FYSETC F6 1.5
-else ifeq ($(HARDWARE_MOTHERBOARD),1141)
-# Duplicator i3 Plus
-else ifeq ($(HARDWARE_MOTHERBOARD),1142)
-# VORON
-else ifeq ($(HARDWARE_MOTHERBOARD),1143)
-# TRONXY V3 1.0
-else ifeq ($(HARDWARE_MOTHERBOARD),1144)
-# Z-Bolt X Series
-else ifeq ($(HARDWARE_MOTHERBOARD),1145)
-# TT OSCAR
-else ifeq ($(HARDWARE_MOTHERBOARD),1146)
-# Overlord/Overlord Pro
-else ifeq ($(HARDWARE_MOTHERBOARD),1147)
-# ADIMLab Gantry v1
-else ifeq ($(HARDWARE_MOTHERBOARD),1148)
-# ADIMLab Gantry v2
-else ifeq ($(HARDWARE_MOTHERBOARD),1149)
-# BIQU Tango V1
-else ifeq ($(HARDWARE_MOTHERBOARD),1150)
-# MKS GEN L V2
-else ifeq ($(HARDWARE_MOTHERBOARD),1151)
-# MKS GEN L V2.1
-else ifeq ($(HARDWARE_MOTHERBOARD),1152)
-# Copymaster 3D
-else ifeq ($(HARDWARE_MOTHERBOARD),1153)
-# Ortur 4
-else ifeq ($(HARDWARE_MOTHERBOARD),1154)
-# Tenlog D3 Hero
-else ifeq ($(HARDWARE_MOTHERBOARD),1155)
+# Zonestar zrib V5.3 (Chinese RAMPS replica)
+else ifeq ($(HARDWARE_MOTHERBOARD),1162)
+# Pxmalion Core I3
+else ifeq ($(HARDWARE_MOTHERBOARD),1163)

 #
 # RAMBo and derivatives
@@ -512,7 +399,7 @@ else ifeq ($(HARDWARE_MOTHERBOARD),1324)
 else ifeq ($(HARDWARE_MOTHERBOARD),1325)
 # Intamsys 4.0 (Funmat HT)
 else ifeq ($(HARDWARE_MOTHERBOARD),1326)
-# Malyan M180 Mainboard Version 2 (no display function, direct gcode only)
+# Malyan M180 Mainboard Version 2 (no display function, direct G-code only)
 else ifeq ($(HARDWARE_MOTHERBOARD),1327)
 # Geeetech GT2560 Rev B for A20(M/T/D)
 else ifeq ($(HARDWARE_MOTHERBOARD),1328)
@@ -28,7 +28,7 @@
 /**
 * Marlin release version identifier
 */
-//#define SHORT_BUILD_VERSION "bugfix-2.0.x"
+//#define SHORT_BUILD_VERSION "bugfix-2.1.x"

 /**
 * Verbose version identifier which should contain a reference to the location
@@ -41,7 +41,7 @@
 * here we define this default string as the date where the latest release
 * version was tagged.
 */
-//#define STRING_DISTRIBUTION_DATE "2022-02-05"
+//#define STRING_DISTRIBUTION_DATE "2022-10-18"

 /**
 * Defines a generic printer name to be output to the LCD after booting Marlin.
@@ -0,0 +1,211 @@
+#
+# Marlin Firmware
+# config.ini - Options to apply before the build
+#
+[config:base]
+ini_use_config                           = none
+
+# Load all config: sections in this file
+;ini_use_config                          = all
+# Load config file relative to Marlin/
+;ini_use_config                          = another.ini
+# Download configurations from GitHub
+;ini_use_config                          = example/Creality/Ender-5 Plus @ bugfix-2.1.x
+# Download configurations from your server
+;ini_use_config                          = https://me.myserver.com/path/to/configs
+# Evaluate config:base and do a config dump
+;ini_use_config                          = base
+;config_export                           = 2
+
+[config:minimal]
+motherboard                              = BOARD_RAMPS_14_EFB
+serial_port                              = 0
+baudrate                                 = 250000
+
+use_watchdog                             = on
+thermal_protection_hotends               = on
+thermal_protection_hysteresis            = 4
+thermal_protection_period                = 40
+
+bufsize                                  = 4
+block_buffer_size                        = 16
+max_cmd_size                             = 96
+
+extruders                                = 1
+temp_sensor_0                            = 1
+
+temp_hysteresis                          = 3
+heater_0_mintemp                         = 5
+heater_0_maxtemp                         = 275
+preheat_1_temp_hotend                    = 180
+
+bang_max                                 = 255
+pidtemp                                  = on
+pid_k1                                   = 0.95
+pid_max                                  = BANG_MAX
+pid_functional_range                     = 10
+
+default_kp                               = 22.20
+default_ki                               = 1.08
+default_kd                               = 114.00
+
+x_driver_type                            = A4988
+y_driver_type                            = A4988
+z_driver_type                            = A4988
+e0_driver_type                           = A4988
+
+x_bed_size                               = 200
+x_min_pos                                = 0
+x_max_pos                                = X_BED_SIZE
+
+y_bed_size                               = 200
+y_min_pos                                = 0
+y_max_pos                                = Y_BED_SIZE
+
+z_min_pos                                = 0
+z_max_pos                                = 200
+
+x_home_dir                               = -1
+y_home_dir                               = -1
+z_home_dir                               = -1
+
+use_xmin_plug                            = on
+use_ymin_plug                            = on
+use_zmin_plug                            = on
+
+x_min_endstop_inverting                  = false
+y_min_endstop_inverting                  = false
+z_min_endstop_inverting                  = false
+
+default_axis_steps_per_unit              = { 80, 80, 400, 500 }
+axis_relative_modes                      = { false, false, false, false }
+default_max_feedrate                     = { 300, 300, 5, 25 }
+default_max_acceleration                 = { 3000, 3000, 100, 10000 }
+
+homing_feedrate_mm_m                     = { (50*60), (50*60), (4*60) }
+homing_bump_divisor                      = { 2, 2, 4 }
+
+x_enable_on                              = 0
+y_enable_on                              = 0
+z_enable_on                              = 0
+e_enable_on                              = 0
+
+invert_x_dir                             = false
+invert_y_dir                             = true
+invert_z_dir                             = false
+invert_e0_dir                            = false
+
+invert_e_step_pin                        = false
+invert_x_step_pin                        = false
+invert_y_step_pin                        = false
+invert_z_step_pin                        = false
+
+disable_x                                = false
+disable_y                                = false
+disable_z                                = false
+disable_e                                = false
+
+proportional_font_ratio                  = 1.0
+default_nominal_filament_dia             = 1.75
+
+junction_deviation_mm                    = 0.013
+
+default_acceleration                     = 3000
+default_travel_acceleration              = 3000
+default_retract_acceleration             = 3000
+
+default_minimumfeedrate                  = 0.0
+default_mintravelfeedrate                = 0.0
+
+minimum_planner_speed                    = 0.05
+min_steps_per_segment                    = 6
+default_minsegmenttime                   = 20000
+
+[config:basic]
+bed_overshoot                            = 10
+busy_while_heating                       = on
+default_ejerk                            = 5.0
+default_keepalive_interval               = 2
+default_leveling_fade_height             = 0.0
+disable_inactive_extruder                = on
+display_charset_hd44780                  = JAPANESE
+eeprom_boot_silent                       = on
+eeprom_chitchat                          = on
+endstoppullups                           = on
+extrude_maxlength                        = 200
+extrude_mintemp                          = 170
+host_keepalive_feature                   = on
+hotend_overshoot                         = 15
+jd_handle_small_segments                 = on
+lcd_info_screen_style                    = 0
+lcd_language                             = en
+max_bed_power                            = 255
+mesh_inset                               = 0
+min_software_endstops                    = on
+max_software_endstops                    = on
+min_software_endstop_x                   = on
+min_software_endstop_y                   = on
+min_software_endstop_z                   = on
+max_software_endstop_x                   = on
+max_software_endstop_y                   = on
+max_software_endstop_z                   = on
+preheat_1_fan_speed                      = 0
+preheat_1_label                          = "PLA"
+preheat_1_temp_bed                       = 70
+prevent_cold_extrusion                   = on
+prevent_lengthy_extrude                  = on
+printjob_timer_autostart                 = on
+probing_margin                           = 10
+show_bootscreen                          = on
+soft_pwm_scale                           = 0
+string_config_h_author                   = "(none, default config)"
+temp_bed_hysteresis                      = 3
+temp_bed_residency_time                  = 10
+temp_bed_window                          = 1
+temp_residency_time                      = 10
+temp_window                              = 1
+validate_homing_endstops                 = on
+xy_probe_feedrate                        = (133*60)
+z_clearance_between_probes               = 5
+z_clearance_deploy_probe                 = 10
+z_clearance_multi_probe                  = 5
+
+[config:advanced]
+arc_support                              = on
+auto_report_temperatures                 = on
+autotemp                                 = on
+autotemp_oldweight                       = 0.98
+bed_check_interval                       = 5000
+default_stepper_deactive_time            = 120
+default_volumetric_extruder_limit        = 0.00
+disable_inactive_e                       = true
+disable_inactive_x                       = true
+disable_inactive_y                       = true
+disable_inactive_z                       = true
+e0_auto_fan_pin                          = -1
+encoder_100x_steps_per_sec               = 80
+encoder_10x_steps_per_sec                = 30
+encoder_rate_multiplier                  = on
+extended_capabilities_report             = on
+extruder_auto_fan_speed                  = 255
+extruder_auto_fan_temperature            = 50
+fanmux0_pin                              = -1
+fanmux1_pin                              = -1
+fanmux2_pin                              = -1
+faster_gcode_parser                      = on
+homing_bump_mm                           = { 5, 5, 2 }
+max_arc_segment_mm                       = 1.0
+min_arc_segment_mm                       = 0.1
+min_circle_segments                      = 72
+n_arc_correction                         = 25
+serial_overrun_protection                = on
+slowdown                                 = on
+slowdown_divisor                         = 2
+temp_sensor_bed                          = 0
+thermal_protection_bed_hysteresis        = 2
+thermocouple_max_errors                  = 15
+tx_buffer_size                           = 0
+watch_bed_temp_increase                  = 2
+watch_bed_temp_period                    = 60
+watch_temp_increase                      = 2
+watch_temp_period                        = 20
@@ -23,6 +23,7 @@

 #include "../../inc/MarlinConfig.h"
 #include "HAL.h"
+#include <avr/wdt.h>

 #ifdef USBCON
  DefaultSerial1 MSerial0(false, Serial);
@@ -36,7 +37,7 @@
 // ------------------------

 // Don't initialize/override variable (which would happen in .init4)
-uint8_t reset_reason __attribute__((section(".noinit")));
+uint8_t MarlinHAL::reset_reason __attribute__((section(".noinit")));

 // ------------------------
 // Public functions
@@ -45,22 +46,22 @@ uint8_t reset_reason __attribute__((section(".noinit")));
 __attribute__((naked))             // Don't output function pro- and epilogue
 __attribute__((used))              // Output the function, even if "not used"
 __attribute__((section(".init3"))) // Put in an early user definable section
-void HAL_save_reset_reason() {
+void save_reset_reason() {
  #if ENABLED(OPTIBOOT_RESET_REASON)
    __asm__ __volatile__(
      A("STS %0, r2")
-      : "=m"(reset_reason)
+      : "=m"(hal.reset_reason)
    );
  #else
-    reset_reason = MCUSR;
+    hal.reset_reason = MCUSR;
  #endif

  // Clear within 16ms since WDRF bit enables a 16ms watchdog timer -> Boot loop
-  MCUSR = 0;
+  hal.clear_reset_source();
  wdt_disable();
 }

-void HAL_init() {
+void MarlinHAL::init() {
  // Init Servo Pins
  #define INIT_SERVO(N) OUT_WRITE(SERVO##N##_PIN, LOW)
  #if HAS_SERVO_0
@@ -79,7 +80,7 @@ void HAL_init() {
  init_pwm_timers();   // Init user timers to default frequency - 1000HZ
 }

-void HAL_reboot() {
+void MarlinHAL::reboot() {
  #if ENABLED(USE_WATCHDOG)
    while (1) { /* run out the watchdog */ }
  #else
@@ -88,6 +89,62 @@ void HAL_reboot() {
  #endif
 }

+// ------------------------
+// Watchdog Timer
+// ------------------------
+
+#if ENABLED(USE_WATCHDOG)
+
+  #include <avr/wdt.h>
+  #include "../../MarlinCore.h"
+
+  // Initialize watchdog with 8s timeout, if possible. Otherwise, make it 4s.
+  void MarlinHAL::watchdog_init() {
+    #if ENABLED(WATCHDOG_DURATION_8S) && defined(WDTO_8S)
+      #define WDTO_NS WDTO_8S
+    #else
+      #define WDTO_NS WDTO_4S
+    #endif
+    #if ENABLED(WATCHDOG_RESET_MANUAL)
+      // Enable the watchdog timer, but only for the interrupt.
+      // Take care, as this requires the correct order of operation, with interrupts disabled.
+      // See the datasheet of any AVR chip for details.
+      wdt_reset();
+      cli();
+      _WD_CONTROL_REG = _BV(_WD_CHANGE_BIT) | _BV(WDE);
+      _WD_CONTROL_REG = _BV(WDIE) | (WDTO_NS & 0x07) | ((WDTO_NS & 0x08) << 2); // WDTO_NS directly does not work. bit 0-2 are consecutive in the register but the highest value bit is at bit 5
+                                                                                // So worked for up to WDTO_2S
+      sei();
+      wdt_reset();
+    #else
+      wdt_enable(WDTO_NS); // The function handles the upper bit correct.
+    #endif
+    //delay(10000); // test it!
+  }
+
+  //===========================================================================
+  //=================================== ISR ===================================
+  //===========================================================================
+
+  // Watchdog timer interrupt, called if main program blocks >4sec and manual reset is enabled.
+  #if ENABLED(WATCHDOG_RESET_MANUAL)
+    ISR(WDT_vect) {
+      sei();  // With the interrupt driven serial we need to allow interrupts.
+      SERIAL_ERROR_MSG(STR_WATCHDOG_FIRED);
+      minkill();  // interrupt-safe final kill and infinite loop
+    }
+  #endif
+
+  // Reset watchdog. MUST be called at least every 4 seconds after the
+  // first watchdog_init or AVR will go into emergency procedures.
+  void MarlinHAL::watchdog_refresh() { wdt_reset(); }
+
+#endif // USE_WATCHDOG
+
+// ------------------------
+// Free Memory Accessor
+// ------------------------
+
 #if ENABLED(SDSUPPORT)

  #include "../../sd/SdFatUtil.h"
@@ -95,20 +152,20 @@ void HAL_reboot() {

 #else // !SDSUPPORT

-extern "C" {
-  extern char __bss_end;
-  extern char __heap_start;
-  extern void* __brkval;
+  extern "C" {
+    extern char __bss_end;
+    extern char __heap_start;
+    extern void* __brkval;

-  int freeMemory() {
-    int free_memory;
-    if ((int)__brkval == 0)
-      free_memory = ((int)&free_memory) - ((int)&__bss_end);
-    else
-      free_memory = ((int)&free_memory) - ((int)__brkval);
-    return free_memory;
+    int freeMemory() {
+      int free_memory;
+      if ((int)__brkval == 0)
+        free_memory = ((int)&free_memory) - ((int)&__bss_end);
+      else
+        free_memory = ((int)&free_memory) - ((int)__brkval);
+      return free_memory;
+    }
  }
-}

 #endif // !SDSUPPORT

@@ -19,16 +19,18 @@
 */
 #pragma once

+/**
+ * HAL for Arduino AVR
+ */
+
 #include "../shared/Marduino.h"
 #include "../shared/HAL_SPI.h"
 #include "fastio.h"
-#include "watchdog.h"
 #include "math.h"

 #ifdef USBCON
  #include <HardwareSerial.h>
 #else
-  #define HardwareSerial_h // Hack to prevent HardwareSerial.h header inclusion
  #include "MarlinSerial.h"
 #endif

@@ -74,9 +76,9 @@
  #define CRITICAL_SECTION_START()  unsigned char _sreg = SREG; cli()
  #define CRITICAL_SECTION_END()    SREG = _sreg
 #endif
-#define ISRS_ENABLED() TEST(SREG, SREG_I)
-#define ENABLE_ISRS()  sei()
-#define DISABLE_ISRS() cli()
+
+#define HAL_CAN_SET_PWM_FREQ   // This HAL supports PWM Frequency adjustment
+#define PWM_FREQUENCY 1000     // Default PWM frequency when set_pwm_duty() is called without set_pwm_frequency()

 // ------------------------
 // Types
@@ -84,16 +86,15 @@

 typedef int8_t pin_t;

-#define SHARED_SERVOS HAS_SERVOS
-#define HAL_SERVO_LIB Servo
+#define SHARED_SERVOS HAS_SERVOS  // Use shared/servos.cpp
+
+class Servo;
+typedef Servo hal_servo_t;

 // ------------------------
-// Public Variables
-// ------------------------
-
-extern uint8_t reset_reason;
-
 // Serial ports
+// ------------------------
+
 #ifdef USBCON
  #include "../../core/serial_hook.h"
  typedef ForwardSerial1Class< decltype(Serial) > DefaultSerial1;
@@ -142,57 +143,15 @@ extern uint8_t reset_reason;
  #endif
 #endif

-// ------------------------
-// Public functions
-// ------------------------
-
-void HAL_init();
-
-//void cli();
-
-//void _delay_ms(const int delay);
-
-inline void HAL_clear_reset_source() { }
-inline uint8_t HAL_get_reset_source() { return reset_reason; }
-
-void HAL_reboot();
-
-#pragma GCC diagnostic push
-#if GCC_VERSION <= 50000
-  #pragma GCC diagnostic ignored "-Wunused-function"
-#endif
-
-extern "C" int freeMemory();
-
-#pragma GCC diagnostic pop
-
+//
 // ADC
-#ifdef DIDR2
-  #define HAL_ANALOG_SELECT(ind) do{ if (ind < 8) SBI(DIDR0, ind); else SBI(DIDR2, ind & 0x07); }while(0)
-#else
-  #define HAL_ANALOG_SELECT(ind) SBI(DIDR0, ind);
-#endif
-
-inline void HAL_adc_init() {
-  ADCSRA = _BV(ADEN) | _BV(ADSC) | _BV(ADIF) | 0x07;
-  DIDR0 = 0;
-  #ifdef DIDR2
-    DIDR2 = 0;
-  #endif
-}
-
-#define SET_ADMUX_ADCSRA(ch) ADMUX = _BV(REFS0) | (ch & 0x07); SBI(ADCSRA, ADSC)
-#ifdef MUX5
-  #define HAL_START_ADC(ch) if (ch > 7) ADCSRB = _BV(MUX5); else ADCSRB = 0; SET_ADMUX_ADCSRA(ch)
-#else
-  #define HAL_START_ADC(ch) ADCSRB = 0; SET_ADMUX_ADCSRA(ch)
-#endif
-
+//
 #define HAL_ADC_VREF        5.0
 #define HAL_ADC_RESOLUTION 10
-#define HAL_READ_ADC()  ADC
-#define HAL_ADC_READY() !TEST(ADCSRA, ADSC)

+//
+// Pin Mapping for M42, M43, M226
+//
 #define GET_PIN_MAP_PIN(index) index
 #define GET_PIN_MAP_INDEX(pin) pin
 #define PARSED_PIN_INDEX(code, dval) parser.intval(code, dval)
@@ -206,30 +165,113 @@ inline void HAL_adc_init() {
 // AVR compatibility
 #define strtof strtod

-#define HAL_CAN_SET_PWM_FREQ   // This HAL supports PWM Frequency adjustment
-#define PWM_FREQUENCY 1000     // Default PWM frequency when set_pwm_duty() is called without set_pwm_frequency()
+// ------------------------
+// Free Memory Accessor
+// ------------------------

-/**
- *  set_pwm_frequency
- *  Sets the frequency of the timer corresponding to the provided pin
- *  as close as possible to the provided desired frequency. Internally
- *  calculates the required waveform generation mode, prescaler and
- *  resolution values required and sets the timer registers accordingly.
- *  NOTE that the frequency is applied to all pins on the timer (Ex OC3A, OC3B and OC3B)
- *  NOTE that there are limitations, particularly if using TIMER2. (see Configuration_adv.h -> FAST FAN PWM Settings)
- */
-void set_pwm_frequency(const pin_t pin, const uint16_t f_desired);
+#pragma GCC diagnostic push
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif

-/**
- * set_pwm_duty
- *  Set the PWM duty cycle of the provided pin to the provided value
- *  Optionally allows inverting the duty cycle [default = false]
- *  Optionally allows changing the maximum size of the provided value to enable finer PWM duty control [default = 255]
- */
-void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size=255, const bool invert=false);
+extern "C" int freeMemory();

-/*
- * init_pwm_timers
- * sets the default frequency for timers 2-5 to 1000HZ
- */
-void init_pwm_timers();
+#pragma GCC diagnostic pop
+
+// ------------------------
+// MarlinHAL Class
+// ------------------------
+
+class MarlinHAL {
+public:
+
+  // Earliest possible init, before setup()
+  MarlinHAL() {}
+
+  // Watchdog
+  static void watchdog_init()    IF_DISABLED(USE_WATCHDOG, {});
+  static void watchdog_refresh() IF_DISABLED(USE_WATCHDOG, {});
+
+  static void init();          // Called early in setup()
+  static void init_board() {}  // Called less early in setup()
+  static void reboot();        // Restart the firmware from 0x0
+
+  // Interrupts
+  static bool isr_state() { return TEST(SREG, SREG_I); }
+  static void isr_on()  { sei(); }
+  static void isr_off() { cli(); }
+
+  static void delay_ms(const int ms) { _delay_ms(ms); }
+
+  // Tasks, called from idle()
+  static void idletask() {}
+
+  // Reset
+  static uint8_t reset_reason;
+  static uint8_t get_reset_source() { return reset_reason; }
+  static void clear_reset_source() { MCUSR = 0; }
+
+  // Free SRAM
+  static int freeMemory() { return ::freeMemory(); }
+
+  //
+  // ADC Methods
+  //
+
+  // Called by Temperature::init once at startup
+  static void adc_init() {
+    ADCSRA = _BV(ADEN) | _BV(ADSC) | _BV(ADIF) | 0x07;
+    DIDR0 = 0;
+    #ifdef DIDR2
+      DIDR2 = 0;
+    #endif
+  }
+
+  // Called by Temperature::init for each sensor at startup
+  static void adc_enable(const uint8_t ch) {
+    #ifdef DIDR2
+      if (ch > 7) { SBI(DIDR2, ch & 0x07); return; }
+    #endif
+    SBI(DIDR0, ch);
+  }
+
+  // Begin ADC sampling on the given channel. Called from Temperature::isr!
+  static void adc_start(const uint8_t ch) {
+    #ifdef MUX5
+      ADCSRB = ch > 7 ? _BV(MUX5) : 0;
+    #else
+      ADCSRB = 0;
+    #endif
+    ADMUX = _BV(REFS0) | (ch & 0x07);
+    SBI(ADCSRA, ADSC);
+  }
+
+  // Is the ADC ready for reading?
+  static bool adc_ready() { return !TEST(ADCSRA, ADSC); }
+
+  // The current value of the ADC register
+  static __typeof__(ADC) adc_value() { return ADC; }
+
+  /**
+   * init_pwm_timers
+   * Set the default frequency for timers 2-5 to 1000HZ
+   */
+  static void init_pwm_timers();
+
+  /**
+   * Set the PWM duty cycle for the pin to the given value.
+   * Optionally invert the duty cycle [default = false]
+   * Optionally change the scale of the provided value to enable finer PWM duty control [default = 255]
+   */
+  static void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size=255, const bool invert=false);
+
+  /**
+   * Set the frequency of the timer for the given pin as close as
+   * possible to the provided desired frequency. Internally calculate
+   * the required waveform generation mode, prescaler, and resolution
+   * values and set timer registers accordingly.
+   * NOTE that the frequency is applied to all pins on the timer (Ex OC3A, OC3B and OC3B)
+   * NOTE that there are limitations, particularly if using TIMER2. (see Configuration_adv.h -> FAST_PWM_FAN Settings)
+   */
+  static void set_pwm_frequency(const pin_t pin, const uint16_t f_desired);
+};
@@ -486,7 +486,7 @@ void MarlinSerial<Cfg>::write(const uint8_t c) {
    const uint8_t i = (tx_buffer.head + 1) & (Cfg::TX_SIZE - 1);

    // If global interrupts are disabled (as the result of being called from an ISR)...
-    if (!ISRS_ENABLED()) {
+    if (!hal.isr_state()) {

      // Make room by polling if it is possible to transmit, and do so!
      while (i == tx_buffer.tail) {
@@ -534,7 +534,7 @@ void MarlinSerial<Cfg>::flushTX() {
    if (!_written) return;

    // If global interrupts are disabled (as the result of being called from an ISR)...
-    if (!ISRS_ENABLED()) {
+    if (!hal.isr_state()) {

      // Wait until everything was transmitted - We must do polling, as interrupts are disabled
      while (tx_buffer.head != tx_buffer.tail || !B_TXC) {
@@ -191,13 +191,13 @@
                   rx_framing_errors;
    static ring_buffer_pos_t rx_max_enqueued;

-    static FORCE_INLINE ring_buffer_pos_t atomic_read_rx_head();
+    FORCE_INLINE static ring_buffer_pos_t atomic_read_rx_head();

    static volatile bool rx_tail_value_not_stable;
    static volatile uint16_t rx_tail_value_backup;

-    static FORCE_INLINE void atomic_set_rx_tail(ring_buffer_pos_t value);
-    static FORCE_INLINE ring_buffer_pos_t atomic_read_rx_tail();
+    FORCE_INLINE static void atomic_set_rx_tail(ring_buffer_pos_t value);
+    FORCE_INLINE static ring_buffer_pos_t atomic_read_rx_tail();

  public:
    FORCE_INLINE static void store_rxd_char();
@@ -66,27 +66,26 @@ static volatile int8_t Channel[_Nbr_16timers];              // counter for the s

 /************ static functions common to all instances ***********************/

-static inline void handle_interrupts(timer16_Sequence_t timer, volatile uint16_t* TCNTn, volatile uint16_t* OCRnA) {
-  if (Channel[timer] < 0)
-    *TCNTn = 0; // channel set to -1 indicated that refresh interval completed so reset the timer
-  else {
-    if (SERVO_INDEX(timer, Channel[timer]) < ServoCount && SERVO(timer, Channel[timer]).Pin.isActive)
-      extDigitalWrite(SERVO(timer, Channel[timer]).Pin.nbr, LOW); // pulse this channel low if activated
-  }
+static inline void handle_interrupts(const timer16_Sequence_t timer, volatile uint16_t* TCNTn, volatile uint16_t* OCRnA) {
+  int8_t cho = Channel[timer];                                        // Handle the prior Channel[timer] first
+  if (cho < 0)                                                        // Channel -1 indicates the refresh interval completed...
+    *TCNTn = 0;                                                       // ...so reset the timer
+  else if (SERVO_INDEX(timer, cho) < ServoCount)                      // prior channel handled?
+    extDigitalWrite(SERVO(timer, cho).Pin.nbr, LOW);                  // pulse the prior channel LOW

-  Channel[timer]++;    // increment to the next channel
-  if (SERVO_INDEX(timer, Channel[timer]) < ServoCount && Channel[timer] < SERVOS_PER_TIMER) {
-    *OCRnA = *TCNTn + SERVO(timer, Channel[timer]).ticks;
-    if (SERVO(timer, Channel[timer]).Pin.isActive)    // check if activated
-      extDigitalWrite(SERVO(timer, Channel[timer]).Pin.nbr, HIGH); // it's an active channel so pulse it high
+  Channel[timer] = ++cho;                                             // Handle the next channel (or 0)
+  if (cho < SERVOS_PER_TIMER && SERVO_INDEX(timer, cho) < ServoCount) {
+    *OCRnA = *TCNTn + SERVO(timer, cho).ticks;                        // set compare to current ticks plus duration
+    if (SERVO(timer, cho).Pin.isActive)                               // activated?
+      extDigitalWrite(SERVO(timer, cho).Pin.nbr, HIGH);               // yes: pulse HIGH
  }
  else {
    // finished all channels so wait for the refresh period to expire before starting over
-    if (((unsigned)*TCNTn) + 4 < usToTicks(REFRESH_INTERVAL))    // allow a few ticks to ensure the next OCR1A not missed
-      *OCRnA = (unsigned int)usToTicks(REFRESH_INTERVAL);
-    else
-      *OCRnA = *TCNTn + 4;  // at least REFRESH_INTERVAL has elapsed
-    Channel[timer] = -1; // this will get incremented at the end of the refresh period to start again at the first channel
+    const unsigned int cval = ((unsigned)*TCNTn) + 32 / (SERVO_TIMER_PRESCALER), // allow 32 cycles to ensure the next OCR1A not missed
+                       ival = (unsigned int)usToTicks(REFRESH_INTERVAL); // at least REFRESH_INTERVAL has elapsed
+    *OCRnA = max(cval, ival);
+
+    Channel[timer] = -1;                                              // reset the timer counter to 0 on the next call
  }
 }

@@ -123,91 +122,102 @@ static inline void handle_interrupts(timer16_Sequence_t timer, volatile uint16_t

 /****************** end of static functions ******************************/

-void initISR(timer16_Sequence_t timer) {
-  #ifdef _useTimer1
-    if (timer == _timer1) {
-      TCCR1A = 0;             // normal counting mode
-      TCCR1B = _BV(CS11);     // set prescaler of 8
-      TCNT1 = 0;              // clear the timer count
-      #if defined(__AVR_ATmega8__) || defined(__AVR_ATmega128__)
-        SBI(TIFR, OCF1A);      // clear any pending interrupts;
-        SBI(TIMSK, OCIE1A);    // enable the output compare interrupt
-      #else
-        // here if not ATmega8 or ATmega128
-        SBI(TIFR1, OCF1A);     // clear any pending interrupts;
-        SBI(TIMSK1, OCIE1A);   // enable the output compare interrupt
-      #endif
-      #ifdef WIRING
-        timerAttach(TIMER1OUTCOMPAREA_INT, Timer1Service);
-      #endif
-    }
-  #endif
+void initISR(const timer16_Sequence_t timer_index) {
+  switch (timer_index) {
+    default: break;

-  #ifdef _useTimer3
-    if (timer == _timer3) {
-      TCCR3A = 0;             // normal counting mode
-      TCCR3B = _BV(CS31);     // set prescaler of 8
-      TCNT3 = 0;              // clear the timer count
-      #ifdef __AVR_ATmega128__
-        SBI(TIFR, OCF3A);     // clear any pending interrupts;
-        SBI(ETIMSK, OCIE3A);  // enable the output compare interrupt
-      #else
-        SBI(TIFR3, OCF3A);   // clear any pending interrupts;
-        SBI(TIMSK3, OCIE3A); // enable the output compare interrupt
-      #endif
-      #ifdef WIRING
-        timerAttach(TIMER3OUTCOMPAREA_INT, Timer3Service);  // for Wiring platform only
-      #endif
-    }
-  #endif
+    #ifdef _useTimer1
+      case _timer1:
+        TCCR1A = 0;             // normal counting mode
+        TCCR1B = _BV(CS11);     // set prescaler of 8
+        TCNT1 = 0;              // clear the timer count
+        #if defined(__AVR_ATmega8__) || defined(__AVR_ATmega128__)
+          SBI(TIFR, OCF1A);      // clear any pending interrupts;
+          SBI(TIMSK, OCIE1A);    // enable the output compare interrupt
+        #else
+          // here if not ATmega8 or ATmega128
+          SBI(TIFR1, OCF1A);     // clear any pending interrupts;
+          SBI(TIMSK1, OCIE1A);   // enable the output compare interrupt
+        #endif
+        #ifdef WIRING
+          timerAttach(TIMER1OUTCOMPAREA_INT, Timer1Service);
+        #endif
+        break;
+    #endif

-  #ifdef _useTimer4
-    if (timer == _timer4) {
-      TCCR4A = 0;             // normal counting mode
-      TCCR4B = _BV(CS41);     // set prescaler of 8
-      TCNT4 = 0;              // clear the timer count
-      TIFR4 = _BV(OCF4A);     // clear any pending interrupts;
-      TIMSK4 = _BV(OCIE4A);   // enable the output compare interrupt
-    }
-  #endif
+    #ifdef _useTimer3
+      case _timer3:
+        TCCR3A = 0;             // normal counting mode
+        TCCR3B = _BV(CS31);     // set prescaler of 8
+        TCNT3 = 0;              // clear the timer count
+        #ifdef __AVR_ATmega128__
+          SBI(TIFR, OCF3A);     // clear any pending interrupts;
+          SBI(ETIMSK, OCIE3A);  // enable the output compare interrupt
+        #else
+          SBI(TIFR3, OCF3A);   // clear any pending interrupts;
+          SBI(TIMSK3, OCIE3A); // enable the output compare interrupt
+        #endif
+        #ifdef WIRING
+          timerAttach(TIMER3OUTCOMPAREA_INT, Timer3Service);  // for Wiring platform only
+        #endif
+        break;
+    #endif

-  #ifdef _useTimer5
-    if (timer == _timer5) {
-      TCCR5A = 0;             // normal counting mode
-      TCCR5B = _BV(CS51);     // set prescaler of 8
-      TCNT5 = 0;              // clear the timer count
-      TIFR5 = _BV(OCF5A);     // clear any pending interrupts;
-      TIMSK5 = _BV(OCIE5A);   // enable the output compare interrupt
-    }
-  #endif
+    #ifdef _useTimer4
+      case _timer4:
+        TCCR4A = 0;             // normal counting mode
+        TCCR4B = _BV(CS41);     // set prescaler of 8
+        TCNT4 = 0;              // clear the timer count
+        TIFR4 = _BV(OCF4A);     // clear any pending interrupts;
+        TIMSK4 = _BV(OCIE4A);   // enable the output compare interrupt
+        break;
+    #endif
+
+    #ifdef _useTimer5
+      case _timer5:
+        TCCR5A = 0;             // normal counting mode
+        TCCR5B = _BV(CS51);     // set prescaler of 8
+        TCNT5 = 0;              // clear the timer count
+        TIFR5 = _BV(OCF5A);     // clear any pending interrupts;
+        TIMSK5 = _BV(OCIE5A);   // enable the output compare interrupt
+        break;
+    #endif
+  }
 }

-void finISR(timer16_Sequence_t timer) {
+void finISR(const timer16_Sequence_t timer_index) {
  // Disable use of the given timer
  #ifdef WIRING
-    if (timer == _timer1) {
-      CBI(
-        #if defined(__AVR_ATmega1281__) || defined(__AVR_ATmega2561__)
-          TIMSK1
-        #else
-          TIMSK
-        #endif
-          , OCIE1A);    // disable timer 1 output compare interrupt
-      timerDetach(TIMER1OUTCOMPAREA_INT);
-    }
-    else if (timer == _timer3) {
-      CBI(
-        #if defined(__AVR_ATmega1281__) || defined(__AVR_ATmega2561__)
-          TIMSK3
-        #else
-          ETIMSK
-        #endif
-          , OCIE3A);    // disable the timer3 output compare A interrupt
-      timerDetach(TIMER3OUTCOMPAREA_INT);
+    switch (timer_index) {
+      default: break;
+
+      case _timer1:
+        CBI(
+          #if defined(__AVR_ATmega1281__) || defined(__AVR_ATmega2561__)
+            TIMSK1
+          #else
+            TIMSK
+          #endif
+          , OCIE1A    // disable timer 1 output compare interrupt
+        );
+        timerDetach(TIMER1OUTCOMPAREA_INT);
+        break;
+
+      case _timer3:
+        CBI(
+          #if defined(__AVR_ATmega1281__) || defined(__AVR_ATmega2561__)
+            TIMSK3
+          #else
+            ETIMSK
+          #endif
+          , OCIE3A    // disable the timer3 output compare A interrupt
+        );
+        timerDetach(TIMER3OUTCOMPAREA_INT);
+        break;
    }
  #else // !WIRING
    // For arduino - in future: call here to a currently undefined function to reset the timer
-    UNUSED(timer);
+    UNUSED(timer_index);
  #endif
 }

@@ -213,6 +213,51 @@ void setup_endstop_interrupts() {
      pciSetup(K_MIN_PIN);
    #endif
  #endif
+  #if HAS_U_MAX
+    #if (digitalPinToInterrupt(U_MAX_PIN) != NOT_AN_INTERRUPT)
+      _ATTACH(U_MAX_PIN);
+    #else
+      static_assert(digitalPinHasPCICR(U_MAX_PIN), "U_MAX_PIN is not interrupt-capable");
+      pciSetup(U_MAX_PIN);
+    #endif
+  #elif HAS_U_MIN
+    #if (digitalPinToInterrupt(U_MIN_PIN) != NOT_AN_INTERRUPT)
+      _ATTACH(U_MIN_PIN);
+    #else
+      static_assert(digitalPinHasPCICR(U_MIN_PIN), "U_MIN_PIN is not interrupt-capable");
+      pciSetup(U_MIN_PIN);
+    #endif
+  #endif
+  #if HAS_V_MAX
+    #if (digitalPinToInterrupt(V_MAX_PIN) != NOT_AN_INTERRUPT)
+      _ATTACH(V_MAX_PIN);
+    #else
+      static_assert(digitalPinHasPCICR(V_MAX_PIN), "V_MAX_PIN is not interrupt-capable");
+      pciSetup(V_MAX_PIN);
+    #endif
+  #elif HAS_V_MIN
+    #if (digitalPinToInterrupt(V_MIN_PIN) != NOT_AN_INTERRUPT)
+      _ATTACH(V_MIN_PIN);
+    #else
+      static_assert(digitalPinHasPCICR(V_MIN_PIN), "V_MIN_PIN is not interrupt-capable");
+      pciSetup(V_MIN_PIN);
+    #endif
+  #endif
+  #if HAS_W_MAX
+    #if (digitalPinToInterrupt(W_MAX_PIN) != NOT_AN_INTERRUPT)
+      _ATTACH(W_MAX_PIN);
+    #else
+      static_assert(digitalPinHasPCICR(W_MAX_PIN), "W_MAX_PIN is not interrupt-capable");
+      pciSetup(W_MAX_PIN);
+    #endif
+  #elif HAS_W_MIN
+    #if (digitalPinToInterrupt(W_MIN_PIN) != NOT_AN_INTERRUPT)
+      _ATTACH(W_MIN_PIN);
+    #else
+      static_assert(digitalPinHasPCICR(W_MIN_PIN), "W_MIN_PIN is not interrupt-capable");
+      pciSetup(W_MIN_PIN);
+    #endif
+  #endif
  #if HAS_X2_MAX
    #if (digitalPinToInterrupt(X2_MAX_PIN) != NOT_AN_INTERRUPT)
      _ATTACH(X2_MAX_PIN);
@@ -107,7 +107,7 @@ const Timer get_pwm_timer(const pin_t pin) {
  return Timer();
 }

-void set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {
+void MarlinHAL::set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {
  const Timer timer = get_pwm_timer(pin);
  if (timer.isProtected || !timer.isPWM) return; // Don't proceed if protected timer or not recognized

@@ -176,7 +176,7 @@ void set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {
    _SET_ICRn(timer, res);                              // Set ICRn value (TOP) = res
 }

-void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
+void MarlinHAL::set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
  // If v is 0 or v_size (max), digitalWrite to LOW or HIGH.
  // Note that digitalWrite also disables PWM output for us (sets COM bit to 0)
  if (v == 0)
@@ -201,7 +201,7 @@ void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255
  }
 }

-void init_pwm_timers() {
+void MarlinHAL::init_pwm_timers() {
  // Init some timer frequencies to a default 1KHz
  const pin_t pwm_pin[] = {
    #ifdef __AVR_ATmega2560__
@@ -293,11 +293,11 @@ enum ClockSource2 : uint8_t {

 #if HAS_MOTOR_CURRENT_PWM
  #if PIN_EXISTS(MOTOR_CURRENT_PWM_XY)
-    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E || P == MOTOR_CURRENT_PWM_Z || P == MOTOR_CURRENT_PWM_XY)
+    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E || P == MOTOR_CURRENT_PWM_E0  || P == MOTOR_CURRENT_PWM_E1 || P == MOTOR_CURRENT_PWM_Z || P == MOTOR_CURRENT_PWM_XY)
  #elif PIN_EXISTS(MOTOR_CURRENT_PWM_Z)
-    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E || P == MOTOR_CURRENT_PWM_Z)
+    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E || P == MOTOR_CURRENT_PWM_E0  || P == MOTOR_CURRENT_PWM_E1 || P == MOTOR_CURRENT_PWM_Z)
  #else
-    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E)
+    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E || P == MOTOR_CURRENT_PWM_E0  || P == MOTOR_CURRENT_PWM_E1)
  #endif
 #else
  #define PWM_CHK_MOTOR_CURRENT(P) false
@@ -25,6 +25,38 @@
 * Test AVR-specific configuration values for errors at compile-time.
 */

+/**
+ * Check for common serial pin conflicts
+ */
+#define CHECK_SERIAL_PIN(N) ( \
+     X_STOP_PIN == N || Y_STOP_PIN == N || Z_STOP_PIN == N \
+  || X_MIN_PIN  == N || Y_MIN_PIN  == N || Z_MIN_PIN  == N \
+  || X_MAX_PIN  == N || Y_MAX_PIN  == N || Z_MAX_PIN  == N \
+  || X_STEP_PIN == N || Y_STEP_PIN == N || Z_STEP_PIN == N \
+  || X_DIR_PIN  == N || Y_DIR_PIN  == N || Z_DIR_PIN  == N \
+  || X_ENA_PIN  == N || Y_ENA_PIN  == N || Z_ENA_PIN  == N \
+  || BTN_EN1    == N || BTN_EN2    == N \
+)
+#if SERIAL_IN_USE(0)
+  // D0-D1. No known conflicts.
+#endif
+#if NOT_TARGET(__AVR_ATmega644P__, __AVR_ATmega1284P__)
+  #if SERIAL_IN_USE(1) && (CHECK_SERIAL_PIN(18) || CHECK_SERIAL_PIN(19))
+    #error "Serial Port 1 pin D18 and/or D19 conflicts with another pin on the board."
+  #endif
+#else
+  #if SERIAL_IN_USE(1) && (CHECK_SERIAL_PIN(10) || CHECK_SERIAL_PIN(11))
+    #error "Serial Port 1 pin D10 and/or D11 conflicts with another pin on the board."
+  #endif
+#endif
+#if SERIAL_IN_USE(2) && (CHECK_SERIAL_PIN(16) || CHECK_SERIAL_PIN(17))
+  #error "Serial Port 2 pin D16 and/or D17 conflicts with another pin on the board."
+#endif
+#if SERIAL_IN_USE(3) && (CHECK_SERIAL_PIN(14) || CHECK_SERIAL_PIN(15))
+  #error "Serial Port 3 pin D14 and/or D15 conflicts with another pin on the board."
+#endif
+#undef CHECK_SERIAL_PIN
+
 /**
 * Checks for FAST PWM
 */
@@ -71,3 +103,7 @@
 #if ENABLED(POSTMORTEM_DEBUGGING)
  #error "POSTMORTEM_DEBUGGING is not supported on AVR boards."
 #endif
+
+#if USING_PULLDOWNS
+  #error "PULLDOWN pin mode is not available on AVR boards."
+#endif
@@ -35,7 +35,7 @@
 // C B A is longIn1
 // D C B A is longIn2
 //
-static FORCE_INLINE uint16_t MultiU24X32toH16(uint32_t longIn1, uint32_t longIn2) {
+FORCE_INLINE static uint16_t MultiU24X32toH16(uint32_t longIn1, uint32_t longIn2) {
  uint8_t tmp1;
  uint8_t tmp2;
  uint16_t intRes;
@@ -89,7 +89,7 @@ static FORCE_INLINE uint16_t MultiU24X32toH16(uint32_t longIn1, uint32_t longIn2
 // uses:
 // r26 to store 0
 // r27 to store the byte 1 of the 24 bit result
-static FORCE_INLINE uint16_t MultiU16X8toH16(uint8_t charIn1, uint16_t intIn2) {
+FORCE_INLINE static uint16_t MultiU16X8toH16(uint8_t charIn1, uint16_t intIn2) {
  uint8_t tmp;
  uint16_t intRes;
  __asm__ __volatile__ (
@@ -74,7 +74,7 @@
 #define MULTI_NAME_PAD 26 // space needed to be pretty if not first name assigned to a pin

 void PRINT_ARRAY_NAME(uint8_t x) {
-  char *name_mem_pointer = (char*)pgm_read_ptr(&pin_array[x].name);
+  PGM_P const name_mem_pointer = (PGM_P)pgm_read_ptr(&pin_array[x].name);
  LOOP_L_N(y, MAX_NAME_LENGTH) {
    char temp_char = pgm_read_byte(name_mem_pointer + y);
    if (temp_char != 0)
@@ -109,12 +109,12 @@ FORCE_INLINE void HAL_timer_start(const uint8_t timer_num, const uint32_t) {
 * (otherwise, characters will be lost due to UART overflow).
 * Then: Stepper, Endstops, Temperature, and -finally- all others.
 */
-#define HAL_timer_isr_prologue(T)
-#define HAL_timer_isr_epilogue(T)
+#define HAL_timer_isr_prologue(T) NOOP
+#define HAL_timer_isr_epilogue(T) NOOP

-/* 18 cycles maximum latency */
 #ifndef HAL_STEP_TIMER_ISR

+/* 18 cycles maximum latency */
 #define HAL_STEP_TIMER_ISR() \
 extern "C" void TIMER1_COMPA_vect() __attribute__ ((signal, naked, used, externally_visible)); \
 extern "C" void TIMER1_COMPA_vect_bottom() asm ("TIMER1_COMPA_vect_bottom") __attribute__ ((used, externally_visible, noinline)); \
@@ -1,70 +0,0 @@
-/**
- * Marlin 3D Printer Firmware
- * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- *
- * Based on Sprinter and grbl.
- * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- *
- */
-#ifdef __AVR__
-
-#include "../../inc/MarlinConfig.h"
-
-#if ENABLED(USE_WATCHDOG)
-
-#include "watchdog.h"
-
-#include "../../MarlinCore.h"
-
-// Initialize watchdog with 8s timeout, if possible. Otherwise, make it 4s.
-void watchdog_init() {
-  #if ENABLED(WATCHDOG_DURATION_8S) && defined(WDTO_8S)
-    #define WDTO_NS WDTO_8S
-  #else
-    #define WDTO_NS WDTO_4S
-  #endif
-  #if ENABLED(WATCHDOG_RESET_MANUAL)
-    // Enable the watchdog timer, but only for the interrupt.
-    // Take care, as this requires the correct order of operation, with interrupts disabled.
-    // See the datasheet of any AVR chip for details.
-    wdt_reset();
-    cli();
-    _WD_CONTROL_REG = _BV(_WD_CHANGE_BIT) | _BV(WDE);
-    _WD_CONTROL_REG = _BV(WDIE) | (WDTO_NS & 0x07) | ((WDTO_NS & 0x08) << 2); // WDTO_NS directly does not work. bit 0-2 are consecutive in the register but the highest value bit is at bit 5
-                                                                              // So worked for up to WDTO_2S
-    sei();
-    wdt_reset();
-  #else
-    wdt_enable(WDTO_NS); // The function handles the upper bit correct.
-  #endif
-  //delay(10000); // test it!
-}
-
-//===========================================================================
-//=================================== ISR ===================================
-//===========================================================================
-
-// Watchdog timer interrupt, called if main program blocks >4sec and manual reset is enabled.
-#if ENABLED(WATCHDOG_RESET_MANUAL)
-  ISR(WDT_vect) {
-    sei();  // With the interrupt driven serial we need to allow interrupts.
-    SERIAL_ERROR_MSG(STR_WATCHDOG_FIRED);
-    minkill();  // interrupt-safe final kill and infinite loop
-  }
-#endif
-
-#endif // USE_WATCHDOG
-#endif // __AVR__
@@ -25,7 +25,7 @@
 #ifdef ARDUINO_ARCH_SAM

 #include "../../inc/MarlinConfig.h"
-#include "HAL.h"
+#include "../../MarlinCore.h"

 #include <Wire.h>
 #include "usb/usb_task.h"
@@ -34,39 +34,33 @@
 // Public Variables
 // ------------------------

-uint16_t HAL_adc_result;
+uint16_t MarlinHAL::adc_result;

 // ------------------------
 // Public functions
 // ------------------------

-TERN_(POSTMORTEM_DEBUGGING, extern void install_min_serial());
+#if ENABLED(POSTMORTEM_DEBUGGING)
+  extern void install_min_serial();
+#endif

-// HAL initialization task
-void HAL_init() {
-  // Initialize the USB stack
+void MarlinHAL::init() {
  #if ENABLED(SDSUPPORT)
    OUT_WRITE(SDSS, HIGH);  // Try to set SDSS inactive before any other SPI users start up
  #endif
-  usb_task_init();
+  usb_task_init();          // Initialize the USB stack
  TERN_(POSTMORTEM_DEBUGGING, install_min_serial()); // Install the min serial handler
 }

-// HAL idle task
-void HAL_idletask() {
-  // Perform USB stack housekeeping
-  usb_task_idle();
+void MarlinHAL::init_board() {
+  #ifdef BOARD_INIT
+    BOARD_INIT();
+  #endif
 }

-// Disable interrupts
-void cli() { noInterrupts(); }
+void MarlinHAL::idletask() { usb_task_idle(); } // Perform USB stack housekeeping

-// Enable interrupts
-void sei() { interrupts(); }
-
-void HAL_clear_reset_source() { }
-
-uint8_t HAL_get_reset_source() {
+uint8_t MarlinHAL::get_reset_source() {
  switch ((RSTC->RSTC_SR >> 8) & 0x07) {
    case 0: return RST_POWER_ON;
    case 1: return RST_BACKUP;
@@ -77,13 +71,105 @@ uint8_t HAL_get_reset_source() {
  }
 }

-void HAL_reboot() { rstc_start_software_reset(RSTC); }
+void MarlinHAL::reboot() { rstc_start_software_reset(RSTC); }

-void _delay_ms(const int delay_ms) {
-  // Todo: port for Due?
-  delay(delay_ms);
+// ------------------------
+// Watchdog Timer
+// ------------------------
+
+#if ENABLED(USE_WATCHDOG)
+
+  // Initialize watchdog - On SAM3X, Watchdog was already configured
+  //  and enabled or disabled at startup, so no need to reconfigure it
+  //  here.
+  void MarlinHAL::watchdog_init() { WDT_Restart(WDT); } // Reset watchdog to start clean
+
+  // Reset watchdog. MUST be called at least every 4 seconds after the
+  // first watchdog_init or AVR will go into emergency procedures.
+  void MarlinHAL::watchdog_refresh() { watchdogReset(); }
+
+#endif
+
+// Override Arduino runtime to either config or disable the watchdog
+//
+// We need to configure the watchdog as soon as possible in the boot
+// process, because watchdog initialization at hardware reset on SAM3X8E
+// is unreliable, and there is risk of unintended resets if we delay
+// that initialization to a later time.
+void watchdogSetup() {
+
+  #if ENABLED(USE_WATCHDOG)
+
+    // 4 seconds timeout
+    uint32_t timeout = TERN(WATCHDOG_DURATION_8S, 8000, 4000);
+
+    // Calculate timeout value in WDT counter ticks: This assumes
+    // the slow clock is running at 32.768 kHz watchdog
+    // frequency is therefore 32768 / 128 = 256 Hz
+    timeout = (timeout << 8) / 1000;
+    if (timeout == 0)
+      timeout = 1;
+    else if (timeout > 0xFFF)
+      timeout = 0xFFF;
+
+    // We want to enable the watchdog with the specified timeout
+    uint32_t value =
+      WDT_MR_WDV(timeout) |               // With the specified timeout
+      WDT_MR_WDD(timeout) |               // and no invalid write window
+    #if !(SAMV70 || SAMV71 || SAME70 || SAMS70)
+      WDT_MR_WDRPROC   |                  // WDT fault resets processor only - We want
+                                          // to keep PIO controller state
+    #endif
+      WDT_MR_WDDBGHLT  |                  // WDT stops in debug state.
+      WDT_MR_WDIDLEHLT;                   // WDT stops in idle state.
+
+    #if ENABLED(WATCHDOG_RESET_MANUAL)
+      // We enable the watchdog timer, but only for the interrupt.
+
+      // Configure WDT to only trigger an interrupt
+      value |= WDT_MR_WDFIEN;             // Enable WDT fault interrupt.
+
+      // Disable WDT interrupt (just in case, to avoid triggering it!)
+      NVIC_DisableIRQ(WDT_IRQn);
+
+      // We NEED memory barriers to ensure Interrupts are actually disabled!
+      // ( https://dzone.com/articles/nvic-disabling-interrupts-on-arm-cortex-m-and-the )
+      __DSB();
+      __ISB();
+
+      // Initialize WDT with the given parameters
+      WDT_Enable(WDT, value);
+
+      // Configure and enable WDT interrupt.
+      NVIC_ClearPendingIRQ(WDT_IRQn);
+      NVIC_SetPriority(WDT_IRQn, 0); // Use highest priority, so we detect all kinds of lockups
+      NVIC_EnableIRQ(WDT_IRQn);
+
+    #else
+
+      // a WDT fault triggers a reset
+      value |= WDT_MR_WDRSTEN;
+
+      // Initialize WDT with the given parameters
+      WDT_Enable(WDT, value);
+
+    #endif
+
+    // Reset the watchdog
+    WDT_Restart(WDT);
+
+  #else
+
+    // Make sure to completely disable the Watchdog
+    WDT_Disable(WDT);
+
+  #endif
 }

+// ------------------------
+// Free Memory Accessor
+// ------------------------
+
 extern "C" {
  extern unsigned int _ebss; // end of bss section
 }
@@ -95,18 +181,9 @@ int freeMemory() {
 }

 // ------------------------
-// ADC
+// Serial Ports
 // ------------------------

-void HAL_adc_start_conversion(const uint8_t ch) {
-  HAL_adc_result = analogRead(ch);
-}
-
-uint16_t HAL_adc_get_result() {
-  // nop
-  return HAL_adc_result;
-}
-
 // Forward the default serial ports
 #if USING_HW_SERIAL0
  DefaultSerial1 MSerial0(false, Serial);
@@ -32,12 +32,15 @@
 #include "../shared/math_32bit.h"
 #include "../shared/HAL_SPI.h"
 #include "fastio.h"
-#include "watchdog.h"

 #include <stdint.h>

 #include "../../core/serial_hook.h"

+// ------------------------
+// Serial ports
+// ------------------------
+
 typedef ForwardSerial1Class< decltype(Serial) > DefaultSerial1;
 typedef ForwardSerial1Class< decltype(Serial1) > DefaultSerial2;
 typedef ForwardSerial1Class< decltype(Serial2) > DefaultSerial3;
@@ -97,60 +100,38 @@ extern DefaultSerial4 MSerial3;
 #include "MarlinSerial.h"
 #include "MarlinSerialUSB.h"

-// On AVR this is in math.h?
-#define square(x) ((x)*(x))
+// ------------------------
+// Types
+// ------------------------

 typedef int8_t pin_t;

-#define SHARED_SERVOS HAS_SERVOS
-#define HAL_SERVO_LIB Servo
+#define SHARED_SERVOS HAS_SERVOS  // Use shared/servos.cpp
+
+class Servo;
+typedef Servo hal_servo_t;

 //
 // Interrupts
 //
-#define CRITICAL_SECTION_START()  uint32_t primask = __get_PRIMASK(); __disable_irq()
-#define CRITICAL_SECTION_END()    if (!primask) __enable_irq()
-#define ISRS_ENABLED() (!__get_PRIMASK())
-#define ENABLE_ISRS()  __enable_irq()
-#define DISABLE_ISRS() __disable_irq()
+#define sei() interrupts()
+#define cli() noInterrupts()

-void cli();                     // Disable interrupts
-void sei();                     // Enable interrupts
-
-void HAL_clear_reset_source();  // clear reset reason
-uint8_t HAL_get_reset_source(); // get reset reason
-
-void HAL_reboot();
+#define CRITICAL_SECTION_START()  const bool _irqon = hal.isr_state(); hal.isr_off()
+#define CRITICAL_SECTION_END()    if (_irqon) hal.isr_on()

 //
 // ADC
 //
-extern uint16_t HAL_adc_result;     // result of last ADC conversion
+#define HAL_ADC_VREF         3.3
+#define HAL_ADC_RESOLUTION  10

 #ifndef analogInputToDigitalPin
  #define analogInputToDigitalPin(p) ((p < 12U) ? (p) + 54U : -1)
 #endif

-#define HAL_ANALOG_SELECT(ch)
-
-inline void HAL_adc_init() {}//todo
-
-#define HAL_ADC_VREF         3.3
-#define HAL_ADC_RESOLUTION  10
-#define HAL_START_ADC(ch)   HAL_adc_start_conversion(ch)
-#define HAL_READ_ADC()      HAL_adc_result
-#define HAL_ADC_READY()     true
-
-void HAL_adc_start_conversion(const uint8_t ch);
-uint16_t HAL_adc_get_result();
-
 //
-// PWM
-//
-inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
-
-//
-// Pin Map
+// Pin Mapping for M42, M43, M226
 //
 #define GET_PIN_MAP_PIN(index) index
 #define GET_PIN_MAP_INDEX(pin) pin
@@ -159,27 +140,18 @@ inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255,
 //
 // Tone
 //
-void toneInit();
 void tone(const pin_t _pin, const unsigned int frequency, const unsigned long duration=0);
 void noTone(const pin_t _pin);

-// Enable hooks into idle and setup for HAL
-#define HAL_IDLETASK 1
-void HAL_idletask();
-void HAL_init();
-
-//
-// Utility functions
-//
-void _delay_ms(const int delay);
+// ------------------------
+// Class Utilities
+// ------------------------

 #pragma GCC diagnostic push
 #if GCC_VERSION <= 50000
  #pragma GCC diagnostic ignored "-Wunused-function"
 #endif

-int freeMemory();
-
 #pragma GCC diagnostic pop

 #ifdef __cplusplus
@@ -189,3 +161,73 @@ char *dtostrf(double __val, signed char __width, unsigned char __prec, char *__s
 #ifdef __cplusplus
  }
 #endif
+
+// Return free RAM between end of heap (or end bss) and whatever is current
+int freeMemory();
+
+// ------------------------
+// MarlinHAL Class
+// ------------------------
+
+class MarlinHAL {
+public:
+
+  // Earliest possible init, before setup()
+  MarlinHAL() {}
+
+  // Watchdog
+  static void watchdog_init()    IF_DISABLED(USE_WATCHDOG, {});
+  static void watchdog_refresh() IF_DISABLED(USE_WATCHDOG, {});
+
+  static void init();          // Called early in setup()
+  static void init_board();    // Called less early in setup()
+  static void reboot();        // Restart the firmware
+
+  // Interrupts
+  static bool isr_state() { return !__get_PRIMASK(); }
+  static void isr_on()  { __enable_irq(); }
+  static void isr_off() { __disable_irq(); }
+
+  static void delay_ms(const int ms) { delay(ms); }
+
+  // Tasks, called from idle()
+  static void idletask();
+
+  // Reset
+  static uint8_t get_reset_source();
+  static void clear_reset_source() {}
+
+  // Free SRAM
+  static int freeMemory() { return ::freeMemory(); }
+
+  //
+  // ADC Methods
+  //
+
+  static uint16_t adc_result;
+
+  // Called by Temperature::init once at startup
+  static void adc_init() {}
+
+  // Called by Temperature::init for each sensor at startup
+  static void adc_enable(const uint8_t /*ch*/) {}
+
+  // Begin ADC sampling on the given channel. Called from Temperature::isr!
+  static void adc_start(const uint8_t ch) { adc_result = analogRead(ch); }
+
+  // Is the ADC ready for reading?
+  static bool adc_ready() { return true; }
+
+  // The current value of the ADC register
+  static uint16_t adc_value() { return adc_result; }
+
+  /**
+   * Set the PWM duty cycle for the pin to the given value.
+   * No inverting the duty cycle in this HAL.
+   * No changing the maximum size of the provided value to enable finer PWM duty control in this HAL.
+   */
+  static void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) {
+    analogWrite(pin, v);
+  }
+
+};
@@ -31,8 +31,6 @@

 /**
 * HAL for Arduino Due and compatible (SAM3X8E)
- *
- * For ARDUINO_ARCH_SAM
 */

 #ifdef ARDUINO_ARCH_SAM
@@ -249,12 +247,12 @@
      b <<= 1; // little setup time

      WRITE(SD_SCK_PIN, HIGH);
-      DELAY_NS(spiDelayNS);
+      DELAY_NS_VAR(spiDelayNS);

      b |= (READ(SD_MISO_PIN) != 0);

      WRITE(SD_SCK_PIN, LOW);
-      DELAY_NS(spiDelayNS);
+      DELAY_NS_VAR(spiDelayNS);
    } while (--bits);
    return b;
  }
@@ -41,7 +41,7 @@
   practice, we need alignment to 256 bytes to make this work in all
   cases */
 __attribute__ ((aligned(256)))
-static DeviceVectors ram_tab = { nullptr };
+static DeviceVectors ram_tab[61] = { nullptr };

 /**
 * This function checks if the exception/interrupt table is already in SRAM or not.
@@ -406,7 +406,7 @@ size_t MarlinSerial<Cfg>::write(const uint8_t c) {
    const uint8_t i = (tx_buffer.head + 1) & (Cfg::TX_SIZE - 1);

    // If global interrupts are disabled (as the result of being called from an ISR)...
-    if (!ISRS_ENABLED()) {
+    if (!hal.isr_state()) {

      // Make room by polling if it is possible to transmit, and do so!
      while (i == tx_buffer.tail) {
@@ -454,7 +454,7 @@ void MarlinSerial<Cfg>::flushTX() {
    if (!_written) return;

    // If global interrupts are disabled (as the result of being called from an ISR)...
-    if (!ISRS_ENABLED()) {
+    if (!hal.isr_state()) {

      // Wait until everything was transmitted - We must do polling, as interrupts are disabled
      while (tx_buffer.head != tx_buffer.tail || !(HWUART->UART_SR & UART_SR_TXEMPTY)) {
@@ -25,7 +25,7 @@

 #if ENABLED(POSTMORTEM_DEBUGGING)

-#include "../shared/HAL_MinSerial.h"
+#include "../shared/MinSerial.h"

 #include <stdarg.h>

@@ -47,12 +47,12 @@
 #include "../shared/servo.h"
 #include "../shared/servo_private.h"

-static volatile int8_t Channel[_Nbr_16timers];              // counter for the servo being pulsed for each timer (or -1 if refresh interval)
+static Flags<_Nbr_16timers> DisablePending; // ISR should disable the timer at the next timer reset

 // ------------------------
 /// Interrupt handler for the TC0 channel 1.
 // ------------------------
-void Servo_Handler(timer16_Sequence_t timer, Tc *pTc, uint8_t channel);
+void Servo_Handler(const timer16_Sequence_t, Tc*, const uint8_t);

 #ifdef _useTimer1
  void HANDLER_FOR_TIMER1() { Servo_Handler(_timer1, TC_FOR_TIMER1, CHANNEL_FOR_TIMER1); }
@@ -70,88 +70,92 @@ void Servo_Handler(timer16_Sequence_t timer, Tc *pTc, uint8_t channel);
  void HANDLER_FOR_TIMER5() { Servo_Handler(_timer5, TC_FOR_TIMER5, CHANNEL_FOR_TIMER5); }
 #endif

-void Servo_Handler(timer16_Sequence_t timer, Tc *tc, uint8_t channel) {
-  // clear interrupt
-  tc->TC_CHANNEL[channel].TC_SR;
-  if (Channel[timer] < 0)
-    tc->TC_CHANNEL[channel].TC_CCR |= TC_CCR_SWTRG; // channel set to -1 indicated that refresh interval completed so reset the timer
-  else if (SERVO_INDEX(timer, Channel[timer]) < ServoCount && SERVO(timer, Channel[timer]).Pin.isActive)
-    extDigitalWrite(SERVO(timer, Channel[timer]).Pin.nbr, LOW); // pulse this channel low if activated
+void Servo_Handler(const timer16_Sequence_t timer, Tc *tc, const uint8_t channel) {
+  static int8_t Channel[_Nbr_16timers];                               // Servo counters to pulse (or -1 for refresh interval)
+  int8_t cho = Channel[timer];                                        // Handle the prior Channel[timer] first
+  if (cho < 0) {                                                      // Channel -1 indicates the refresh interval completed...
+    tc->TC_CHANNEL[channel].TC_CCR |= TC_CCR_SWTRG;                   // ...so reset the timer
+    if (DisablePending[timer]) {
+      // Disabling only after the full servo period expires prevents
+      // pulses being too close together if immediately re-enabled.
+      DisablePending.clear(timer);
+      TC_Stop(tc, channel);
+      tc->TC_CHANNEL[channel].TC_SR;                                  // clear interrupt
+      return;
+    }
+  }
+  else if (SERVO_INDEX(timer, cho) < ServoCount)                      // prior channel handled?
+    extDigitalWrite(SERVO(timer, cho).Pin.nbr, LOW);                  // pulse the prior channel LOW

-  Channel[timer]++;    // increment to the next channel
-  if (SERVO_INDEX(timer, Channel[timer]) < ServoCount && Channel[timer] < SERVOS_PER_TIMER) {
-    tc->TC_CHANNEL[channel].TC_RA = tc->TC_CHANNEL[channel].TC_CV + SERVO(timer,Channel[timer]).ticks;
-    if (SERVO(timer,Channel[timer]).Pin.isActive)    // check if activated
-      extDigitalWrite(SERVO(timer, Channel[timer]).Pin.nbr, HIGH); // its an active channel so pulse it high
+  Channel[timer] = ++cho;                                             // go to the next channel (or 0)
+  if (cho < SERVOS_PER_TIMER && SERVO_INDEX(timer, cho) < ServoCount) {
+    tc->TC_CHANNEL[channel].TC_RA = tc->TC_CHANNEL[channel].TC_CV + SERVO(timer, cho).ticks;
+    if (SERVO(timer, cho).Pin.isActive)                               // activated?
+      extDigitalWrite(SERVO(timer, cho).Pin.nbr, HIGH);               // yes: pulse HIGH
  }
  else {
    // finished all channels so wait for the refresh period to expire before starting over
-    tc->TC_CHANNEL[channel].TC_RA =
-      tc->TC_CHANNEL[channel].TC_CV < usToTicks(REFRESH_INTERVAL) - 4
-        ? (unsigned int)usToTicks(REFRESH_INTERVAL) // allow a few ticks to ensure the next OCR1A not missed
-        : tc->TC_CHANNEL[channel].TC_CV + 4;        // at least REFRESH_INTERVAL has elapsed
-    Channel[timer] = -1; // this will get incremented at the end of the refresh period to start again at the first channel
+    const unsigned int cval = tc->TC_CHANNEL[channel].TC_CV + 128 / (SERVO_TIMER_PRESCALER), // allow 128 cycles to ensure the next CV not missed
+                       ival = (unsigned int)usToTicks(REFRESH_INTERVAL); // at least REFRESH_INTERVAL has elapsed
+    tc->TC_CHANNEL[channel].TC_RA = max(cval, ival);
+
+    Channel[timer] = -1;                                              // reset the timer CCR on the next call
  }
+
+  tc->TC_CHANNEL[channel].TC_SR;                                      // clear interrupt
 }

 static void _initISR(Tc *tc, uint32_t channel, uint32_t id, IRQn_Type irqn) {
  pmc_enable_periph_clk(id);
  TC_Configure(tc, channel,
-    TC_CMR_TCCLKS_TIMER_CLOCK3 | // MCK/32
-    TC_CMR_WAVE |                // Waveform mode
-    TC_CMR_WAVSEL_UP_RC );       // Counter running up and reset when equals to RC
+      TC_CMR_WAVE                   // Waveform mode
+    | TC_CMR_WAVSEL_UP_RC           // Counter running up and reset when equal to RC
+    | (SERVO_TIMER_PRESCALER ==   2 ? TC_CMR_TCCLKS_TIMER_CLOCK1 : 0) // MCK/2
+    | (SERVO_TIMER_PRESCALER ==   8 ? TC_CMR_TCCLKS_TIMER_CLOCK2 : 0) // MCK/8
+    | (SERVO_TIMER_PRESCALER ==  32 ? TC_CMR_TCCLKS_TIMER_CLOCK3 : 0) // MCK/32
+    | (SERVO_TIMER_PRESCALER == 128 ? TC_CMR_TCCLKS_TIMER_CLOCK4 : 0) // MCK/128
+  );

-  /* 84MHz, MCK/32, for 1.5ms: 3937 */
-  TC_SetRA(tc, channel, 2625); // 1ms
+  // Wait 1ms before the first ISR
+  TC_SetRA(tc, channel, (F_CPU) / (SERVO_TIMER_PRESCALER) / 1000UL); // 1ms

-  /* Configure and enable interrupt */
+  // Configure and enable interrupt
  NVIC_EnableIRQ(irqn);
-  // TC_IER_CPAS: RA Compare
-  tc->TC_CHANNEL[channel].TC_IER = TC_IER_CPAS;
+  tc->TC_CHANNEL[channel].TC_IER = TC_IER_CPAS; // TC_IER_CPAS: RA Compare

  // Enables the timer clock and performs a software reset to start the counting
  TC_Start(tc, channel);
 }

-void initISR(timer16_Sequence_t timer) {
-  #ifdef _useTimer1
-    if (timer == _timer1)
-      _initISR(TC_FOR_TIMER1, CHANNEL_FOR_TIMER1, ID_TC_FOR_TIMER1, IRQn_FOR_TIMER1);
-  #endif
-  #ifdef _useTimer2
-    if (timer == _timer2)
-      _initISR(TC_FOR_TIMER2, CHANNEL_FOR_TIMER2, ID_TC_FOR_TIMER2, IRQn_FOR_TIMER2);
-  #endif
-  #ifdef _useTimer3
-    if (timer == _timer3)
-      _initISR(TC_FOR_TIMER3, CHANNEL_FOR_TIMER3, ID_TC_FOR_TIMER3, IRQn_FOR_TIMER3);
-  #endif
-  #ifdef _useTimer4
-    if (timer == _timer4)
-      _initISR(TC_FOR_TIMER4, CHANNEL_FOR_TIMER4, ID_TC_FOR_TIMER4, IRQn_FOR_TIMER4);
-  #endif
-  #ifdef _useTimer5
-    if (timer == _timer5)
-      _initISR(TC_FOR_TIMER5, CHANNEL_FOR_TIMER5, ID_TC_FOR_TIMER5, IRQn_FOR_TIMER5);
-  #endif
+void initISR(const timer16_Sequence_t timer_index) {
+  CRITICAL_SECTION_START();
+  const bool disable_soon = DisablePending[timer_index];
+  DisablePending.clear(timer_index);
+  CRITICAL_SECTION_END();
+
+  if (!disable_soon) switch (timer_index) {
+    default: break;
+    #ifdef _useTimer1
+      case _timer1: return _initISR(TC_FOR_TIMER1, CHANNEL_FOR_TIMER1, ID_TC_FOR_TIMER1, IRQn_FOR_TIMER1);
+    #endif
+    #ifdef _useTimer2
+      case _timer2: return _initISR(TC_FOR_TIMER2, CHANNEL_FOR_TIMER2, ID_TC_FOR_TIMER2, IRQn_FOR_TIMER2);
+    #endif
+    #ifdef _useTimer3
+      case _timer3: return _initISR(TC_FOR_TIMER3, CHANNEL_FOR_TIMER3, ID_TC_FOR_TIMER3, IRQn_FOR_TIMER3);
+    #endif
+    #ifdef _useTimer4
+      case _timer4: return _initISR(TC_FOR_TIMER4, CHANNEL_FOR_TIMER4, ID_TC_FOR_TIMER4, IRQn_FOR_TIMER4);
+    #endif
+    #ifdef _useTimer5
+      case _timer5: return _initISR(TC_FOR_TIMER5, CHANNEL_FOR_TIMER5, ID_TC_FOR_TIMER5, IRQn_FOR_TIMER5);
+    #endif
+  }
 }

-void finISR(timer16_Sequence_t) {
-  #ifdef _useTimer1
-    TC_Stop(TC_FOR_TIMER1, CHANNEL_FOR_TIMER1);
-  #endif
-  #ifdef _useTimer2
-    TC_Stop(TC_FOR_TIMER2, CHANNEL_FOR_TIMER2);
-  #endif
-  #ifdef _useTimer3
-    TC_Stop(TC_FOR_TIMER3, CHANNEL_FOR_TIMER3);
-  #endif
-  #ifdef _useTimer4
-    TC_Stop(TC_FOR_TIMER4, CHANNEL_FOR_TIMER4);
-  #endif
-  #ifdef _useTimer5
-    TC_Stop(TC_FOR_TIMER5, CHANNEL_FOR_TIMER5);
-  #endif
+void finISR(const timer16_Sequence_t timer_index) {
+  // Timer is disabled from the ISR, to ensure proper final pulse length.
+  DisablePending.set(timer_index);
 }

 #endif // HAS_SERVOS
@@ -37,7 +37,7 @@
 #define _useTimer5

 #define TRIM_DURATION             2   // compensation ticks to trim adjust for digitalWrite delays
-#define SERVO_TIMER_PRESCALER     32  // timer prescaler
+#define SERVO_TIMER_PRESCALER     2   // timer prescaler

 /*
  TC0, chan 0 => TC0_Handler
@@ -35,7 +35,7 @@
 static pin_t tone_pin;
 volatile static int32_t toggles;

-void tone(const pin_t _pin, const unsigned int frequency, const unsigned long duration) {
+void tone(const pin_t _pin, const unsigned int frequency, const unsigned long duration/*=0*/) {
  tone_pin = _pin;
  toggles = 2 * frequency * duration / 1000;
  HAL_timer_start(MF_TIMER_TONE, 2 * frequency);
@@ -199,8 +199,7 @@ static bool ee_PageWrite(uint16_t page, const void *data) {
  for (i = 0; i <PageSize >> 2; i++)
    pageContents[i] = (((uint32_t*)data)[i]) | (~(pageContents[i] ^ ((uint32_t*)data)[i]));

-  DEBUG_ECHO_START();
-  DEBUG_ECHOLNPGM("EEPROM PageWrite   ", page);
+  DEBUG_ECHO_MSG("EEPROM PageWrite   ", page);
  DEBUG_ECHOLNPGM(" in FLASH address ", (uint32_t)addrflash);
  DEBUG_ECHOLNPGM(" base address     ", (uint32_t)getFlashStorage(0));
  DEBUG_FLUSH();
@@ -245,8 +244,7 @@ static bool ee_PageWrite(uint16_t page, const void *data) {
    // Reenable interrupts
    __enable_irq();

-    DEBUG_ECHO_START();
-    DEBUG_ECHOLNPGM("EEPROM Unlock failure for page ", page);
+    DEBUG_ECHO_MSG("EEPROM Unlock failure for page ", page);
    return false;
  }

@@ -270,8 +268,7 @@ static bool ee_PageWrite(uint16_t page, const void *data) {
    // Reenable interrupts
    __enable_irq();

-    DEBUG_ECHO_START();
-    DEBUG_ECHOLNPGM("EEPROM Write failure for page ", page);
+    DEBUG_ECHO_MSG("EEPROM Write failure for page ", page);

    return false;
  }
@@ -286,8 +283,7 @@ static bool ee_PageWrite(uint16_t page, const void *data) {
  if (memcmp(getFlashStorage(page),data,PageSize)) {

    #ifdef EE_EMU_DEBUG
-      DEBUG_ECHO_START();
-      DEBUG_ECHOLNPGM("EEPROM Verify Write failure for page ", page);
+      DEBUG_ECHO_MSG("EEPROM Verify Write failure for page ", page);

      ee_Dump( page, (uint32_t *)addrflash);
      ee_Dump(-page, data);
@@ -325,8 +321,7 @@ static bool ee_PageErase(uint16_t page) {
  uint16_t i;
  uint32_t addrflash = uint32_t(getFlashStorage(page));

-  DEBUG_ECHO_START();
-  DEBUG_ECHOLNPGM("EEPROM PageErase  ", page);
+  DEBUG_ECHO_MSG("EEPROM PageErase  ", page);
  DEBUG_ECHOLNPGM(" in FLASH address ", (uint32_t)addrflash);
  DEBUG_ECHOLNPGM(" base address     ", (uint32_t)getFlashStorage(0));
  DEBUG_FLUSH();
@@ -370,8 +365,7 @@ static bool ee_PageErase(uint16_t page) {
    // Reenable interrupts
    __enable_irq();

-    DEBUG_ECHO_START();
-    DEBUG_ECHOLNPGM("EEPROM Unlock failure for page ",page);
+    DEBUG_ECHO_MSG("EEPROM Unlock failure for page ",page);

    return false;
  }
@@ -394,8 +388,7 @@ static bool ee_PageErase(uint16_t page) {
    // Reenable interrupts
    __enable_irq();

-    DEBUG_ECHO_START();
-    DEBUG_ECHOLNPGM("EEPROM Erase failure for page ",page);
+    DEBUG_ECHO_MSG("EEPROM Erase failure for page ",page);

    return false;
  }
@@ -410,8 +403,7 @@ static bool ee_PageErase(uint16_t page) {
  uint32_t * aligned_src = (uint32_t *) addrflash;
  for (i = 0; i < PageSize >> 2; i++) {
    if (*aligned_src++ != 0xFFFFFFFF) {
-      DEBUG_ECHO_START();
-      DEBUG_ECHOLNPGM("EEPROM Verify Erase failure for page ",page);
+      DEBUG_ECHO_MSG("EEPROM Verify Erase failure for page ",page);
      ee_Dump(page, (uint32_t *)addrflash);
      return false;
    }
@@ -921,8 +913,7 @@ static void ee_Init() {
  // If all groups seem to be used, default to first group
  if (curGroup >= GroupCount) curGroup = 0;

-  DEBUG_ECHO_START();
-  DEBUG_ECHOLNPGM("EEPROM Current Group: ",curGroup);
+  DEBUG_ECHO_MSG("EEPROM Current Group: ",curGroup);
  DEBUG_FLUSH();

  // Now, validate that all the other group pages are empty
@@ -931,8 +922,7 @@ static void ee_Init() {

    for (int page = 0; page < PagesPerGroup; page++) {
      if (!ee_IsPageClean(grp * PagesPerGroup + page)) {
-        DEBUG_ECHO_START();
-        DEBUG_ECHOLNPGM("EEPROM Page ", page, " not clean on group ", grp);
+        DEBUG_ECHO_MSG("EEPROM Page ", page, " not clean on group ", grp);
        DEBUG_FLUSH();
        ee_PageErase(grp * PagesPerGroup + page);
      }
@@ -948,15 +938,13 @@ static void ee_Init() {
    }
  }

-  DEBUG_ECHO_START();
-  DEBUG_ECHOLNPGM("EEPROM Active page: ", curPage);
+  DEBUG_ECHO_MSG("EEPROM Active page: ", curPage);
  DEBUG_FLUSH();

  // Make sure the pages following the first clean one are also clean
  for (int page = curPage + 1; page < PagesPerGroup; page++) {
    if (!ee_IsPageClean(curGroup * PagesPerGroup + page)) {
-      DEBUG_ECHO_START();
-      DEBUG_ECHOLNPGM("EEPROM Page ", page, " not clean on active group ", curGroup);
+      DEBUG_ECHO_MSG("EEPROM Page ", page, " not clean on active group ", curGroup);
      DEBUG_FLUSH();
      ee_Dump(curGroup * PagesPerGroup + page, getFlashStorage(curGroup * PagesPerGroup + page));
      ee_PageErase(curGroup * PagesPerGroup + page);
@@ -70,4 +70,10 @@ void setup_endstop_interrupts() {
  TERN_(HAS_J_MIN, _ATTACH(J_MIN_PIN));
  TERN_(HAS_K_MAX, _ATTACH(K_MAX_PIN));
  TERN_(HAS_K_MIN, _ATTACH(K_MIN_PIN));
+  TERN_(HAS_U_MAX, _ATTACH(U_MAX_PIN));
+  TERN_(HAS_U_MIN, _ATTACH(U_MIN_PIN));
+  TERN_(HAS_V_MAX, _ATTACH(V_MAX_PIN));
+  TERN_(HAS_V_MIN, _ATTACH(V_MIN_PIN));
+  TERN_(HAS_W_MAX, _ATTACH(W_MAX_PIN));
+  TERN_(HAS_W_MIN, _ATTACH(W_MIN_PIN));
 }
@@ -25,6 +25,30 @@
 * Test Arduino Due specific configuration values for errors at compile-time.
 */

+/**
+ * Check for common serial pin conflicts
+ */
+#define CHECK_SERIAL_PIN(N) ( \
+     X_STOP_PIN == N || Y_STOP_PIN == N || Z_STOP_PIN == N \
+  || X_MIN_PIN  == N || Y_MIN_PIN  == N || Z_MIN_PIN  == N \
+  || X_MAX_PIN  == N || Y_MAX_PIN  == N || Z_MAX_PIN  == N \
+  || X_STEP_PIN == N || Y_STEP_PIN == N || Z_STEP_PIN == N \
+  || X_DIR_PIN  == N || Y_DIR_PIN  == N || Z_DIR_PIN  == N \
+  || X_ENA_PIN  == N || Y_ENA_PIN  == N || Z_ENA_PIN  == N \
+)
+#if SERIAL_IN_USE(0) // D0-D1. No known conflicts.
+#endif
+#if SERIAL_IN_USE(1) && (CHECK_SERIAL_PIN(18) || CHECK_SERIAL_PIN(19))
+  #error "Serial Port 1 pin D18 and/or D19 conflicts with another pin on the board."
+#endif
+#if SERIAL_IN_USE(2) && (CHECK_SERIAL_PIN(16) || CHECK_SERIAL_PIN(17))
+  #error "Serial Port 2 pin D16 and/or D17 conflicts with another pin on the board."
+#endif
+#if SERIAL_IN_USE(3) && (CHECK_SERIAL_PIN(14) || CHECK_SERIAL_PIN(15))
+  #error "Serial Port 3 pin D14 and/or D15 conflicts with another pin on the board."
+#endif
+#undef CHECK_SERIAL_PIN
+
 /**
 * HARDWARE VS. SOFTWARE SPI COMPATIBILITY
 *
@@ -59,3 +83,7 @@
 #if HAS_TMC_SW_SERIAL
  #error "TMC220x Software Serial is not supported on the DUE platform."
 #endif
+
+#if USING_PULLDOWNS
+  #error "PULLDOWN pin mode is not available on DUE boards."
+#endif
@@ -70,7 +70,7 @@
 #define PRINT_PIN_ANALOG(p) do{ sprintf_P(buffer, PSTR(" (A%2d)  "), DIGITAL_PIN_TO_ANALOG_PIN(pin)); SERIAL_ECHO(buffer); }while(0)
 #define GET_ARRAY_PIN(p) pin_array[p].pin
 #define GET_ARRAY_IS_DIGITAL(p) pin_array[p].is_digital
-#define VALID_PIN(pin) (pin >= 0 && pin < (int8_t)NUMBER_PINS_TOTAL ? 1 : 0)
+#define VALID_PIN(pin) (pin >= 0 && pin < int8_t(NUMBER_PINS_TOTAL))
 #define DIGITAL_PIN_TO_ANALOG_PIN(p) int(p - analogInputToDigitalPin(0))
 #define IS_ANALOG(P) WITHIN(P, char(analogInputToDigitalPin(0)), char(analogInputToDigitalPin(NUM_ANALOG_INPUTS - 1)))
 #define pwm_status(pin) (((g_pinStatus[pin] & 0xF) == PIN_STATUS_PWM) && \
@@ -86,7 +86,6 @@ bool GET_PINMODE(int8_t pin) {  // 1: output, 0: input
          || pwm_status(pin));
 }

-
 void pwm_details(int32_t pin) {
  if (pwm_status(pin)) {
    uint32_t chan = g_APinDescription[pin].ulPWMChannel;
@@ -89,10 +89,17 @@ void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency) {
  NVIC_SetPriority(irq, timer_config[timer_num].priority);

  // wave mode, reset counter on match with RC,
-  TC_Configure(tc, channel, TC_CMR_WAVE | TC_CMR_WAVSEL_UP_RC | TC_CMR_TCCLKS_TIMER_CLOCK1);
+  TC_Configure(tc, channel,
+      TC_CMR_WAVE
+    | TC_CMR_WAVSEL_UP_RC
+    | (HAL_TIMER_PRESCALER ==   2 ? TC_CMR_TCCLKS_TIMER_CLOCK1 : 0)
+    | (HAL_TIMER_PRESCALER ==   8 ? TC_CMR_TCCLKS_TIMER_CLOCK2 : 0)
+    | (HAL_TIMER_PRESCALER ==  32 ? TC_CMR_TCCLKS_TIMER_CLOCK3 : 0)
+    | (HAL_TIMER_PRESCALER == 128 ? TC_CMR_TCCLKS_TIMER_CLOCK4 : 0)
+  );

  // Set compare value
-  TC_SetRC(tc, channel, VARIANT_MCK / 2 / frequency);
+  TC_SetRC(tc, channel, VARIANT_MCK / (HAL_TIMER_PRESCALER) / frequency);

  // And start timer
  TC_Start(tc, channel);
@@ -35,7 +35,8 @@
 typedef uint32_t hal_timer_t;
 #define HAL_TIMER_TYPE_MAX 0xFFFFFFFF

-#define HAL_TIMER_RATE         ((F_CPU) / 2)    // frequency of timers peripherals
+#define HAL_TIMER_PRESCALER    2
+#define HAL_TIMER_RATE         ((F_CPU) / (HAL_TIMER_PRESCALER))  // frequency of timers peripherals

 #ifndef MF_TIMER_STEP
  #define MF_TIMER_STEP         2  // Timer Index for Stepper
@@ -125,4 +126,4 @@ FORCE_INLINE static void HAL_timer_isr_prologue(const uint8_t timer_num) {
  pConfig->pTimerRegs->TC_CHANNEL[pConfig->channel].TC_SR;
 }

-#define HAL_timer_isr_epilogue(T)
+#define HAL_timer_isr_epilogue(T) NOOP
@@ -6,14 +6,14 @@
 #
 import pioutil
 if pioutil.is_pio_build():
-	import platform
-	current_OS = platform.system()
+    import platform
+    current_OS = platform.system()

-	if current_OS == 'Windows':
+    if current_OS == 'Windows':

-		Import("env")
+        Import("env")

-		# Use bossac.exe on Windows
-		env.Replace(
-			UPLOADCMD="bossac --info --unlock --write --verify --reset --erase -U false --boot $SOURCE"
-		)
+        # Use bossac.exe on Windows
+        env.Replace(
+            UPLOADCMD="bossac --info --unlock --write --verify --reset --erase -U false --boot $SOURCE"
+        )
@@ -1059,7 +1059,7 @@ static inline void convert_64_bit_to_byte_array(uint64_t value, uint8_t *data)
    while (val_index < 8)
    {
        data[val_index++] = value & 0xFF;
-        value = value >> 8;
+        value >>= 8;
    }
 }

@@ -62,7 +62,7 @@ void usb_task_idle(void) {
    // Attend SD card access from the USB MSD -- Prioritize access to improve speed
    int delay = 2;
    while (main_b_msc_enable && --delay > 0) {
-      if (udi_msc_process_trans()) delay = 10000;
+      if (udi_msc_process_trans()) delay = 20;

      // Reset the watchdog, just to be sure
      REG_WDT_CR = WDT_CR_WDRSTT | WDT_CR_KEY(0xA5);
@@ -1,114 +0,0 @@
-/**
- * Marlin 3D Printer Firmware
- * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- *
- * Based on Sprinter and grbl.
- * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- *
- */
-#ifdef ARDUINO_ARCH_SAM
-
-#include "../../inc/MarlinConfig.h"
-#include "../../MarlinCore.h"
-#include "watchdog.h"
-
-// Override Arduino runtime to either config or disable the watchdog
-//
-// We need to configure the watchdog as soon as possible in the boot
-// process, because watchdog initialization at hardware reset on SAM3X8E
-// is unreliable, and there is risk of unintended resets if we delay
-// that initialization to a later time.
-void watchdogSetup() {
-
-  #if ENABLED(USE_WATCHDOG)
-
-    // 4 seconds timeout
-    uint32_t timeout = TERN(WATCHDOG_DURATION_8S, 8000, 4000);
-
-    // Calculate timeout value in WDT counter ticks: This assumes
-    // the slow clock is running at 32.768 kHz watchdog
-    // frequency is therefore 32768 / 128 = 256 Hz
-    timeout = (timeout << 8) / 1000;
-    if (timeout == 0)
-      timeout = 1;
-    else if (timeout > 0xFFF)
-      timeout = 0xFFF;
-
-    // We want to enable the watchdog with the specified timeout
-    uint32_t value =
-      WDT_MR_WDV(timeout) |               // With the specified timeout
-      WDT_MR_WDD(timeout) |               // and no invalid write window
-    #if !(SAMV70 || SAMV71 || SAME70 || SAMS70)
-      WDT_MR_WDRPROC   |                  // WDT fault resets processor only - We want
-                                          // to keep PIO controller state
-    #endif
-      WDT_MR_WDDBGHLT  |                  // WDT stops in debug state.
-      WDT_MR_WDIDLEHLT;                   // WDT stops in idle state.
-
-    #if ENABLED(WATCHDOG_RESET_MANUAL)
-      // We enable the watchdog timer, but only for the interrupt.
-
-      // Configure WDT to only trigger an interrupt
-      value |= WDT_MR_WDFIEN;             // Enable WDT fault interrupt.
-
-      // Disable WDT interrupt (just in case, to avoid triggering it!)
-      NVIC_DisableIRQ(WDT_IRQn);
-
-      // We NEED memory barriers to ensure Interrupts are actually disabled!
-      // ( https://dzone.com/articles/nvic-disabling-interrupts-on-arm-cortex-m-and-the )
-      __DSB();
-      __ISB();
-
-      // Initialize WDT with the given parameters
-      WDT_Enable(WDT, value);
-
-      // Configure and enable WDT interrupt.
-      NVIC_ClearPendingIRQ(WDT_IRQn);
-      NVIC_SetPriority(WDT_IRQn, 0); // Use highest priority, so we detect all kinds of lockups
-      NVIC_EnableIRQ(WDT_IRQn);
-
-    #else
-
-      // a WDT fault triggers a reset
-      value |= WDT_MR_WDRSTEN;
-
-      // Initialize WDT with the given parameters
-      WDT_Enable(WDT, value);
-
-    #endif
-
-    // Reset the watchdog
-    WDT_Restart(WDT);
-
-  #else
-
-    // Make sure to completely disable the Watchdog
-    WDT_Disable(WDT);
-
-  #endif
-}
-
-#if ENABLED(USE_WATCHDOG)
-  // Initialize watchdog - On SAM3X, Watchdog was already configured
-  //  and enabled or disabled at startup, so no need to reconfigure it
-  //  here.
-  void watchdog_init() {
-    // Reset watchdog to start clean
-    WDT_Restart(WDT);
-  }
-#endif // USE_WATCHDOG
-
-#endif
@@ -52,7 +52,7 @@
 // Externs
 // ------------------------

-portMUX_TYPE spinlock = portMUX_INITIALIZER_UNLOCKED;
+portMUX_TYPE MarlinHAL::spinlock = portMUX_INITIALIZER_UNLOCKED;

 // ------------------------
 // Local defines
@@ -64,7 +64,8 @@ portMUX_TYPE spinlock = portMUX_INITIALIZER_UNLOCKED;
 // Public Variables
 // ------------------------

-uint16_t HAL_adc_result;
+uint16_t MarlinHAL::adc_result;
+pwm_pin_t MarlinHAL::pwm_pin_data[MAX_EXPANDER_BITS];

 // ------------------------
 // Private Variables
@@ -73,9 +74,16 @@ uint16_t HAL_adc_result;
 esp_adc_cal_characteristics_t characteristics[ADC_ATTEN_MAX];
 adc_atten_t attenuations[ADC1_CHANNEL_MAX] = {};
 uint32_t thresholds[ADC_ATTEN_MAX];
-volatile int numPWMUsed = 0,
-             pwmPins[MAX_PWM_PINS],
-             pwmValues[MAX_PWM_PINS];
+
+volatile int numPWMUsed = 0;
+volatile struct { pin_t pin; int value; } pwmState[MAX_PWM_PINS];
+
+pin_t chan_pin[CHANNEL_MAX_NUM + 1] = { 0 }; // PWM capable IOpins - not 0 or >33 on ESP32
+
+struct {
+  uint32_t freq; // ledcReadFreq doesn't work if a duty hasn't been set yet!
+  uint16_t res;
+} pwmInfo[(CHANNEL_MAX_NUM + 1) / 2];

 // ------------------------
 // Public functions
@@ -95,20 +103,22 @@ volatile int numPWMUsed = 0,
 #endif

 #if ENABLED(USE_ESP32_EXIO)
+
  HardwareSerial YSerial2(2);

  void Write_EXIO(uint8_t IO, uint8_t v) {
-    if (ISRS_ENABLED()) {
-      DISABLE_ISRS();
+    if (hal.isr_state()) {
+      hal.isr_off();
      YSerial2.write(0x80 | (((char)v) << 5) | (IO - 100));
-      ENABLE_ISRS();
+      hal.isr_on();
    }
    else
      YSerial2.write(0x80 | (((char)v) << 5) | (IO - 100));
  }
+
 #endif

-void HAL_init_board() {
+void MarlinHAL::init_board() {
  #if ENABLED(USE_ESP32_TASK_WDT)
    esp_task_wdt_init(10, true);
  #endif
@@ -154,27 +164,51 @@ void HAL_init_board() {
  #endif
 }

-void HAL_idletask() {
+void MarlinHAL::idletask() {
  #if BOTH(WIFISUPPORT, OTASUPPORT)
    OTA_handle();
  #endif
  TERN_(ESP3D_WIFISUPPORT, esp3dlib.idletask());
 }

-void HAL_clear_reset_source() { }
+uint8_t MarlinHAL::get_reset_source() { return rtc_get_reset_reason(1); }

-uint8_t HAL_get_reset_source() { return rtc_get_reset_reason(1); }
-
-void HAL_reboot() { ESP.restart(); }
+void MarlinHAL::reboot() { ESP.restart(); }

 void _delay_ms(int delay_ms) { delay(delay_ms); }

 // return free memory between end of heap (or end bss) and whatever is current
-int freeMemory() { return ESP.getFreeHeap(); }
+int MarlinHAL::freeMemory() { return ESP.getFreeHeap(); }
+
+// ------------------------
+// Watchdog Timer
+// ------------------------
+
+#if ENABLED(USE_WATCHDOG)
+
+  #define WDT_TIMEOUT_US TERN(WATCHDOG_DURATION_8S, 8000000, 4000000) // 4 or 8 second timeout
+
+  extern "C" {
+    esp_err_t esp_task_wdt_reset();
+  }
+
+  void watchdogSetup() {
+    // do whatever. don't remove this function.
+  }
+
+  void MarlinHAL::watchdog_init() {
+    // TODO
+  }
+
+  // Reset watchdog.
+  void MarlinHAL::watchdog_refresh() { esp_task_wdt_reset(); }
+
+#endif

 // ------------------------
 // ADC
 // ------------------------
+
 #define ADC1_CHANNEL(pin) ADC1_GPIO ## pin ## _CHANNEL

 adc1_channel_t get_channel(int pin) {
@@ -196,24 +230,24 @@ void adc1_set_attenuation(adc1_channel_t chan, adc_atten_t atten) {
  }
 }

-void HAL_adc_init() {
+void MarlinHAL::adc_init() {
  // Configure ADC
  adc1_config_width(ADC_WIDTH_12Bit);

  // Configure channels only if used as (re-)configuring a pin for ADC that is used elsewhere might have adverse effects
-  TERN_(HAS_TEMP_ADC_0, adc1_set_attenuation(get_channel(TEMP_0_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_TEMP_ADC_1, adc1_set_attenuation(get_channel(TEMP_1_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_TEMP_ADC_2, adc1_set_attenuation(get_channel(TEMP_2_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_TEMP_ADC_3, adc1_set_attenuation(get_channel(TEMP_3_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_TEMP_ADC_4, adc1_set_attenuation(get_channel(TEMP_4_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_TEMP_ADC_5, adc1_set_attenuation(get_channel(TEMP_5_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_TEMP_ADC_6, adc2_set_attenuation(get_channel(TEMP_6_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_TEMP_ADC_7, adc3_set_attenuation(get_channel(TEMP_7_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_HEATED_BED, adc1_set_attenuation(get_channel(TEMP_BED_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_TEMP_CHAMBER, adc1_set_attenuation(get_channel(TEMP_CHAMBER_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_TEMP_PROBE, adc1_set_attenuation(get_channel(TEMP_PROBE_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_TEMP_COOLER, adc1_set_attenuation(get_channel(TEMP_COOLER_PIN), ADC_ATTEN_11db));
-  TERN_(HAS_TEMP_BOARD, adc1_set_attenuation(get_channel(TEMP_BOARD_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_ADC_0,        adc1_set_attenuation(get_channel(TEMP_0_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_ADC_1,        adc1_set_attenuation(get_channel(TEMP_1_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_ADC_2,        adc1_set_attenuation(get_channel(TEMP_2_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_ADC_3,        adc1_set_attenuation(get_channel(TEMP_3_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_ADC_4,        adc1_set_attenuation(get_channel(TEMP_4_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_ADC_5,        adc1_set_attenuation(get_channel(TEMP_5_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_ADC_6,        adc2_set_attenuation(get_channel(TEMP_6_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_ADC_7,        adc3_set_attenuation(get_channel(TEMP_7_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_HEATED_BED,        adc1_set_attenuation(get_channel(TEMP_BED_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_CHAMBER,      adc1_set_attenuation(get_channel(TEMP_CHAMBER_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_PROBE,        adc1_set_attenuation(get_channel(TEMP_PROBE_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_COOLER,       adc1_set_attenuation(get_channel(TEMP_COOLER_PIN), ADC_ATTEN_11db));
+  TERN_(HAS_TEMP_BOARD,        adc1_set_attenuation(get_channel(TEMP_BOARD_PIN), ADC_ATTEN_11db));
  TERN_(FILAMENT_WIDTH_SENSOR, adc1_set_attenuation(get_channel(FILWIDTH_PIN), ADC_ATTEN_11db));

  // Note that adc2 is shared with the WiFi module, which has higher priority, so the conversion may fail.
@@ -228,11 +262,16 @@ void HAL_adc_init() {
  }
 }

-void HAL_adc_start_conversion(const uint8_t adc_pin) {
-  const adc1_channel_t chan = get_channel(adc_pin);
+#ifndef ADC_REFERENCE_VOLTAGE
+  #define ADC_REFERENCE_VOLTAGE 3.3
+#endif
+
+void MarlinHAL::adc_start(const pin_t pin) {
+  const adc1_channel_t chan = get_channel(pin);
  uint32_t mv;
  esp_adc_cal_get_voltage((adc_channel_t)chan, &characteristics[attenuations[chan]], &mv);
-  HAL_adc_result = mv * 1023.0 / 3300.0;
+
+  adc_result = mv * isr_float_t(1023) / isr_float_t(ADC_REFERENCE_VOLTAGE) / isr_float_t(1000);

  // Change the attenuation level based on the new reading
  adc_atten_t atten;
@@ -249,25 +288,106 @@ void HAL_adc_start_conversion(const uint8_t adc_pin) {
  adc1_set_attenuation(chan, atten);
 }

-void analogWrite(pin_t pin, int value) {
-  // Use ledc hardware for internal pins
-  if (pin < 34) {
-    static int cnt_channel = 1, pin_to_channel[40] = { 0 };
-    if (pin_to_channel[pin] == 0) {
-      ledcAttachPin(pin, cnt_channel);
-      ledcSetup(cnt_channel, 490, 8);
-      ledcWrite(cnt_channel, value);
-      pin_to_channel[pin] = cnt_channel++;
+// ------------------------
+// PWM
+// ------------------------
+
+int8_t channel_for_pin(const uint8_t pin) {
+  for (int i = 0; i <= CHANNEL_MAX_NUM; i++)
+    if (chan_pin[i] == pin) return i;
+  return -1;
+}
+
+// get PWM channel for pin - if none then attach a new one
+// return -1 if fail or invalid pin#, channel # (0-15) if success
+int8_t get_pwm_channel(const pin_t pin, const uint32_t freq, const uint16_t res) {
+  if (!WITHIN(pin, 1, MAX_PWM_IOPIN)) return -1; // Not a hardware PWM pin!
+  int8_t cid = channel_for_pin(pin);
+  if (cid >= 0) return cid;
+
+  // Find an empty adjacent channel (same timer & freq/res)
+  for (int i = 0; i <= CHANNEL_MAX_NUM; i++) {
+    if (chan_pin[i] == 0) {
+      if (chan_pin[i ^ 0x1] != 0) {
+        if (pwmInfo[i / 2].freq == freq && pwmInfo[i / 2].res == res) {
+          chan_pin[i] = pin; // Allocate PWM to this channel
+          ledcAttachPin(pin, i);
+          return i;
+        }
+      }
+      else if (cid == -1)    // Pair of empty channels?
+        cid = i & 0xFE;      // Save lower channel number
    }
-    ledcWrite(pin_to_channel[pin], value);
+  }
+  // not attached, is an empty timer slot avail?
+  if (cid >= 0) {
+    chan_pin[cid] = pin;
+    pwmInfo[cid / 2].freq = freq;
+    pwmInfo[cid / 2].res = res;
+    ledcSetup(cid, freq, res);
+    ledcAttachPin(pin, cid);
+  }
+  return cid; // -1 if no channel avail
+}
+
+void MarlinHAL::set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=_BV(PWM_RESOLUTION)-1*/, const bool invert/*=false*/) {
+  #if ENABLED(I2S_STEPPER_STREAM)
+    if (pin > 127) {
+      const uint8_t pinlo = pin & 0x7F;
+      pwm_pin_t &pindata = pwm_pin_data[pinlo];
+      const uint32_t duty = map(invert ? v_size - v : v, 0, v_size, 0, pindata.pwm_cycle_ticks);
+      if (duty == 0 || duty == pindata.pwm_cycle_ticks) { // max or min (i.e., on/off)
+        pindata.pwm_duty_ticks = 0;  // turn off PWM for this pin
+        duty ? SBI32(i2s_port_data, pinlo) : CBI32(i2s_port_data, pinlo); // set pin level
+      }
+      else
+        pindata.pwm_duty_ticks = duty; // PWM duty count = # of 4µs ticks per full PWM cycle
+    }
+    else
+  #endif
+    {
+      const int8_t cid = get_pwm_channel(pin, PWM_FREQUENCY, PWM_RESOLUTION);
+      if (cid >= 0) {
+        const uint32_t duty = map(invert ? v_size - v : v, 0, v_size, 0, _BV(PWM_RESOLUTION)-1);
+        ledcWrite(cid, duty);
+      }
+    }
+}
+
+int8_t MarlinHAL::set_pwm_frequency(const pin_t pin, const uint32_t f_desired) {
+  #if ENABLED(I2S_STEPPER_STREAM)
+    if (pin > 127) {
+      pwm_pin_data[pin & 0x7F].pwm_cycle_ticks = 1000000UL / f_desired / 4; // # of 4µs ticks per full PWM cycle
+      return 0;
+    }
+    else
+  #endif
+    {
+      const int8_t cid = channel_for_pin(pin);
+      if (cid >= 0) {
+        if (f_desired == ledcReadFreq(cid)) return cid; // no freq change
+        ledcDetachPin(chan_pin[cid]);
+        chan_pin[cid] = 0;              // remove old freq channel
+      }
+      return get_pwm_channel(pin, f_desired, PWM_RESOLUTION); // try for new one
+    }
+}
+
+// use hardware PWM if avail, if not then ISR
+void analogWrite(const pin_t pin, const uint16_t value, const uint32_t freq/*=PWM_FREQUENCY*/, const uint16_t res/*=8*/) { // always 8 bit resolution!
+  // Use ledc hardware for internal pins
+  const int8_t cid = get_pwm_channel(pin, freq, res);
+  if (cid >= 0) {
+    ledcWrite(cid, value); // set duty value
    return;
  }

+  // not a hardware PWM pin OR no PWM channels available
  int idx = -1;

  // Search Pin
  for (int i = 0; i < numPWMUsed; ++i)
-    if (pwmPins[i] == pin) { idx = i; break; }
+    if (pwmState[i].pin == pin) { idx = i; break; }

  // not found ?
  if (idx < 0) {
@@ -276,7 +396,7 @@ void analogWrite(pin_t pin, int value) {

    // Take new slot for pin
    idx = numPWMUsed;
-    pwmPins[idx] = pin;
+    pwmState[idx].pin = pin;
    // Start timer on first use
    if (idx == 0) HAL_timer_start(MF_TIMER_PWM, PWM_TIMER_FREQUENCY);

@@ -284,7 +404,7 @@ void analogWrite(pin_t pin, int value) {
  }

  // Use 7bit internal value - add 1 to have 100% high at 255
-  pwmValues[idx] = (value + 1) / 2;
+  pwmState[idx].value = (value + 1) / 2;
 }

 // Handle PWM timer interrupt
@@ -295,9 +415,9 @@ HAL_PWM_TIMER_ISR() {

  for (int i = 0; i < numPWMUsed; ++i) {
    if (count == 0)                   // Start of interval
-      WRITE(pwmPins[i], pwmValues[i] ? HIGH : LOW);
-    else if (pwmValues[i] == count)   // End of duration
-      WRITE(pwmPins[i], LOW);
+      digitalWrite(pwmState[i].pin, pwmState[i].value ? HIGH : LOW);
+    else if (pwmState[i].value == count)   // End of duration
+      digitalWrite(pwmState[i].pin, LOW);
  }

  // 128 for 7 Bit resolution
@@ -32,7 +32,6 @@
 #include "../shared/HAL_SPI.h"

 #include "fastio.h"
-#include "watchdog.h"
 #include "i2s.h"

 #if ENABLED(WIFISUPPORT)
@@ -49,8 +48,6 @@
 // Defines
 // ------------------------

-extern portMUX_TYPE spinlock;
-
 #define MYSERIAL1 flushableSerial

 #if EITHER(WIFISUPPORT, ESP3D_WIFISUPPORT)
@@ -63,26 +60,33 @@ extern portMUX_TYPE spinlock;
  #endif
 #endif

-#define CRITICAL_SECTION_START() portENTER_CRITICAL(&spinlock)
-#define CRITICAL_SECTION_END()   portEXIT_CRITICAL(&spinlock)
-#define ISRS_ENABLED() (spinlock.owner == portMUX_FREE_VAL)
-#define ENABLE_ISRS()  if (spinlock.owner != portMUX_FREE_VAL) portEXIT_CRITICAL(&spinlock)
-#define DISABLE_ISRS() portENTER_CRITICAL(&spinlock)
+#define CRITICAL_SECTION_START() portENTER_CRITICAL(&hal.spinlock)
+#define CRITICAL_SECTION_END()   portEXIT_CRITICAL(&hal.spinlock)
+
+#define HAL_CAN_SET_PWM_FREQ   // This HAL supports PWM Frequency adjustment
+#define PWM_FREQUENCY  1000u   // Default PWM frequency when set_pwm_duty() is called without set_pwm_frequency()
+#define PWM_RESOLUTION   10u   // Default PWM bit resolution
+#define CHANNEL_MAX_NUM  15u   // max PWM channel # to allocate (7 to only use low speed, 15 to use low & high)
+#define MAX_PWM_IOPIN    33u   // hardware pwm pins < 34
+#ifndef MAX_EXPANDER_BITS
+  #define MAX_EXPANDER_BITS 32 // I2S expander bit width (max 32)
+#endif

 // ------------------------
 // Types
 // ------------------------

+typedef double isr_float_t;   // FPU ops are used for single-precision, so use double for ISRs.
 typedef int16_t pin_t;

-#define HAL_SERVO_LIB Servo
+typedef struct pwm_pin {
+  uint32_t pwm_cycle_ticks = 1000000UL / (PWM_FREQUENCY) / 4; // # ticks per pwm cycle
+  uint32_t pwm_tick_count = 0;  // current tick count
+  uint32_t pwm_duty_ticks = 0;  // # of ticks for current duty cycle
+} pwm_pin_t;

-// ------------------------
-// Public Variables
-// ------------------------
-
-/** result of last ADC conversion */
-extern uint16_t HAL_adc_result;
+class Servo;
+typedef Servo hal_servo_t;

 // ------------------------
 // Public functions
@@ -91,59 +95,18 @@ extern uint16_t HAL_adc_result;
 //
 // Tone
 //
-void toneInit();
 void tone(const pin_t _pin, const unsigned int frequency, const unsigned long duration=0);
 void noTone(const pin_t _pin);
+int8_t get_pwm_channel(const pin_t pin, const uint32_t freq, const uint16_t res);
+void analogWrite(const pin_t pin, const uint16_t value, const uint32_t freq=PWM_FREQUENCY, const uint16_t res=8);

-// clear reset reason
-void HAL_clear_reset_source();
-
-// reset reason
-uint8_t HAL_get_reset_source();
-
-void HAL_reboot();
-
-void _delay_ms(int delay);
-
-#pragma GCC diagnostic push
-#if GCC_VERSION <= 50000
-  #pragma GCC diagnostic ignored "-Wunused-function"
-#endif
-
-int freeMemory();
-
-#pragma GCC diagnostic pop
-
-void analogWrite(pin_t pin, int value);
-
-// ADC
-#define HAL_ANALOG_SELECT(pin)
-
-void HAL_adc_init();
-
-#define HAL_ADC_VREF         3.3
-#define HAL_ADC_RESOLUTION  10
-#define HAL_START_ADC(pin)  HAL_adc_start_conversion(pin)
-#define HAL_READ_ADC()      HAL_adc_result
-#define HAL_ADC_READY()     true
-
-void HAL_adc_start_conversion(const uint8_t adc_pin);
-
-// PWM
-inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
-
-// Pin Map
+//
+// Pin Mapping for M42, M43, M226
+//
 #define GET_PIN_MAP_PIN(index) index
 #define GET_PIN_MAP_INDEX(pin) pin
 #define PARSED_PIN_INDEX(code, dval) parser.intval(code, dval)

-// Enable hooks into idle and setup for HAL
-#define HAL_IDLETASK 1
-#define BOARD_INIT() HAL_init_board()
-void HAL_idletask();
-inline void HAL_init() {}
-void HAL_init_board();
-
 #if ENABLED(USE_ESP32_EXIO)
  void Write_EXIO(uint8_t IO, uint8_t v);
 #endif
@@ -188,3 +151,96 @@ FORCE_INLINE static void DELAY_CYCLES(uint32_t x) {
  }

 }
+
+// ------------------------
+// Class Utilities
+// ------------------------
+
+#pragma GCC diagnostic push
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+int freeMemory();
+
+#pragma GCC diagnostic pop
+
+void _delay_ms(const int ms);
+
+// ------------------------
+// MarlinHAL Class
+// ------------------------
+
+#define HAL_ADC_VREF         3.3
+#define HAL_ADC_RESOLUTION  10
+
+class MarlinHAL {
+public:
+
+  // Earliest possible init, before setup()
+  MarlinHAL() {}
+
+  // Watchdog
+  static void watchdog_init()    IF_DISABLED(USE_WATCHDOG, {});
+  static void watchdog_refresh() IF_DISABLED(USE_WATCHDOG, {});
+
+  static void init() {}        // Called early in setup()
+  static void init_board();    // Called less early in setup()
+  static void reboot();        // Restart the firmware
+
+  // Interrupts
+  static portMUX_TYPE spinlock;
+  static bool isr_state() { return spinlock.owner == portMUX_FREE_VAL; }
+  static void isr_on()  { if (spinlock.owner != portMUX_FREE_VAL) portEXIT_CRITICAL(&spinlock); }
+  static void isr_off() { portENTER_CRITICAL(&spinlock); }
+
+  static void delay_ms(const int ms) { _delay_ms(ms); }
+
+  // Tasks, called from idle()
+  static void idletask();
+
+  // Reset
+  static uint8_t get_reset_source();
+  static void clear_reset_source() {}
+
+  // Free SRAM
+  static int freeMemory();
+
+  static pwm_pin_t pwm_pin_data[MAX_EXPANDER_BITS];
+
+  //
+  // ADC Methods
+  //
+
+  static uint16_t adc_result;
+
+  // Called by Temperature::init once at startup
+  static void adc_init();
+
+  // Called by Temperature::init for each sensor at startup
+  static void adc_enable(const pin_t pin) {}
+
+  // Begin ADC sampling on the given pin. Called from Temperature::isr!
+  static void adc_start(const pin_t pin);
+
+  // Is the ADC ready for reading?
+  static bool adc_ready() { return true; }
+
+  // The current value of the ADC register
+  static uint16_t adc_value() { return adc_result; }
+
+  /**
+   * If not already allocated, allocate a hardware PWM channel
+   * to the pin and set the duty cycle..
+   * Optionally invert the duty cycle [default = false]
+   * Optionally change the scale of the provided value to enable finer PWM duty control [default = 255]
+   */
+  static void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size=255, const bool invert=false);
+
+  /**
+   * Allocate and set the frequency of a hardware PWM pin
+   * Returns -1 if no pin available.
+   */
+  static int8_t set_pwm_frequency(const pin_t pin, const uint32_t f_desired);
+
+};
@@ -31,20 +31,18 @@
 // so we only allocate servo channels up high to avoid side effects with regards to analogWrite (fans, leds, laser pwm etc.)
 int Servo::channel_next_free = 12;

-Servo::Servo() {
-  channel = channel_next_free++;
-}
+Servo::Servo() {}

 int8_t Servo::attach(const int inPin) {
-  if (channel >= CHANNEL_MAX_NUM) return -1;
  if (inPin > 0) pin = inPin;
-
-  ledcSetup(channel, 50, 16); // channel X, 50 Hz, 16-bit depth
-  ledcAttachPin(pin, channel);
-  return true;
+  channel = get_pwm_channel(pin, 50u, 16u);
+  return channel; // -1 if no PWM avail.
 }

-void Servo::detach() { ledcDetachPin(pin); }
+// leave channel connected to servo - set duty to zero
+void Servo::detach() {
+  if (channel >= 0) ledcWrite(channel, 0);
+}

 int Servo::read() { return degrees; }

@@ -52,7 +50,7 @@ void Servo::write(int inDegrees) {
  degrees = constrain(inDegrees, MIN_ANGLE, MAX_ANGLE);
  int us = map(degrees, MIN_ANGLE, MAX_ANGLE, MIN_PULSE_WIDTH, MAX_PULSE_WIDTH);
  int duty = map(us, 0, TAU_USEC, 0, MAX_COMPARE);
-  ledcWrite(channel, duty);
+  if (channel >= 0) ledcWrite(channel, duty); // don't save duty for servos!
 }

 void Servo::move(const int value) {
@@ -30,8 +30,7 @@ class Servo {
                   MAX_PULSE_WIDTH = 2400,  // Longest pulse sent to a servo
                   TAU_MSEC = 20,
                   TAU_USEC = (TAU_MSEC * 1000),
-                   MAX_COMPARE = _BV(16) - 1, // 65535
-                   CHANNEL_MAX_NUM = 16;
+                   MAX_COMPARE = _BV(16) - 1; // 65535

 public:
  Servo();
@@ -35,7 +35,7 @@
 static pin_t tone_pin;
 volatile static int32_t toggles;

-void tone(const pin_t _pin, const unsigned int frequency, const unsigned long duration) {
+void tone(const pin_t _pin, const unsigned int frequency, const unsigned long duration/*=0*/) {
  tone_pin = _pin;
  toggles = 2 * frequency * duration / 1000;
  HAL_timer_start(MF_TIMER_TONE, 2 * frequency);
@@ -65,4 +65,10 @@ void setup_endstop_interrupts() {
  TERN_(HAS_J_MIN, _ATTACH(J_MIN_PIN));
  TERN_(HAS_K_MAX, _ATTACH(K_MAX_PIN));
  TERN_(HAS_K_MIN, _ATTACH(K_MIN_PIN));
+  TERN_(HAS_U_MAX, _ATTACH(U_MAX_PIN));
+  TERN_(HAS_U_MIN, _ATTACH(U_MIN_PIN));
+  TERN_(HAS_V_MAX, _ATTACH(V_MAX_PIN));
+  TERN_(HAS_V_MIN, _ATTACH(V_MIN_PIN));
+  TERN_(HAS_W_MAX, _ATTACH(W_MAX_PIN));
+  TERN_(HAS_W_MIN, _ATTACH(W_MIN_PIN));
 }
@@ -139,22 +139,40 @@ static void IRAM_ATTR i2s_intr_handler_default(void *arg) {
 }

 void stepperTask(void *parameter) {
-  uint32_t remaining = 0;
+  uint32_t nextMainISR = 0;
+  #if ENABLED(LIN_ADVANCE)
+    uint32_t nextAdvanceISR = Stepper::LA_ADV_NEVER;
+  #endif

-  while (1) {
+  for (;;) {
    xQueueReceive(dma.queue, &dma.current, portMAX_DELAY);
    dma.rw_pos = 0;

    while (dma.rw_pos < DMA_SAMPLE_COUNT) {
      // Fill with the port data post pulse_phase until the next step
-      if (remaining) {
+      if (nextMainISR && TERN1(LIN_ADVANCE, nextAdvanceISR))
        i2s_push_sample();
-        remaining--;
-      }
-      else {
+
+      // i2s_push_sample() is also called from Stepper::pulse_phase_isr() and Stepper::advance_isr()
+      // in a rare case where both are called, we need to double decrement the counters
+      const uint8_t push_count = 1 + (!nextMainISR && TERN0(LIN_ADVANCE, !nextAdvanceISR));
+
+      #if ENABLED(LIN_ADVANCE)
+        if (!nextAdvanceISR) {
+          Stepper::advance_isr();
+          nextAdvanceISR = Stepper::la_interval;
+        }
+        else if (nextAdvanceISR == Stepper::LA_ADV_NEVER)
+          nextAdvanceISR = Stepper::la_interval;
+      #endif
+
+      if (!nextMainISR) {
        Stepper::pulse_phase_isr();
-        remaining = Stepper::block_phase_isr();
+        nextMainISR = Stepper::block_phase_isr();
      }
+
+      nextMainISR -= push_count;
+      TERN_(LIN_ADVANCE, nextAdvanceISR -= push_count);
    }
  }
 }
@@ -337,6 +355,26 @@ uint8_t i2s_state(uint8_t pin) {
 }

 void i2s_push_sample() {
+  // Every 4µs (when space in DMA buffer) toggle each expander PWM output using
+  // the current duty cycle/frequency so they sync with any steps (once
+  // through the DMA/FIFO buffers).  PWM signal inversion handled by other functions
+  LOOP_L_N(p, MAX_EXPANDER_BITS) {
+    if (hal.pwm_pin_data[p].pwm_duty_ticks > 0) { // pin has active pwm?
+      if (hal.pwm_pin_data[p].pwm_tick_count == 0) {
+        if (TEST32(i2s_port_data, p)) {  // hi->lo
+          CBI32(i2s_port_data, p);
+          hal.pwm_pin_data[p].pwm_tick_count = hal.pwm_pin_data[p].pwm_cycle_ticks - hal.pwm_pin_data[p].pwm_duty_ticks;
+        }
+        else { // lo->hi
+          SBI32(i2s_port_data, p);
+          hal.pwm_pin_data[p].pwm_tick_count = hal.pwm_pin_data[p].pwm_duty_ticks;
+        }
+      }
+      else
+        hal.pwm_pin_data[p].pwm_tick_count--;
+    }
+  }
+
  dma.current[dma.rw_pos++] = i2s_port_data;
 }

@@ -20,3 +20,10 @@
 *
 */
 #pragma once
+
+//
+// Board-specific options need to be defined before HAL.h
+//
+#if MB(MKS_TINYBEE)
+  #define MAX_EXPANDER_BITS 24  // TinyBee has 3 x HC595
+#endif
@@ -25,8 +25,8 @@
  #error "EMERGENCY_PARSER is not yet implemented for ESP32. Disable EMERGENCY_PARSER to continue."
 #endif

-#if ENABLED(FAST_PWM_FAN) || SPINDLE_LASER_FREQUENCY
-  #error "Features requiring Hardware PWM (FAST_PWM_FAN, SPINDLE_LASER_FREQUENCY) are not yet supported on ESP32."
+#if (ENABLED(SPINDLE_LASER_USE_PWM) && SPINDLE_LASER_FREQUENCY > 78125) || (ENABLED(FAST_PWM_FAN_FREQUENCY) && FAST_PWM_FAN_FREQUENCY > 78125)
+  #error "SPINDLE_LASER_FREQUENCY and FAST_PWM_FREQUENCY maximum value is 78125Hz for ESP32."
 #endif

 #if HAS_TMC_SW_SERIAL
@@ -40,3 +40,19 @@
 #if ENABLED(POSTMORTEM_DEBUGGING)
  #error "POSTMORTEM_DEBUGGING is not yet supported on ESP32."
 #endif
+
+#if MB(MKS_TINYBEE) && ENABLED(FAST_PWM_FAN)
+  #error "FAST_PWM_FAN is not available on TinyBee."
+#endif
+
+#if BOTH(I2S_STEPPER_STREAM, BABYSTEPPING) && DISABLED(INTEGRATED_BABYSTEPPING)
+  #error "BABYSTEPPING on I2S stream requires INTEGRATED_BABYSTEPPING."
+#endif
+
+#if USING_PULLDOWNS
+  #error "PULLDOWN pin mode is not available on ESP32 boards."
+#endif
+
+#if BOTH(I2S_STEPPER_STREAM, LIN_ADVANCE) && DISABLED(EXPERIMENTAL_I2S_LA)
+  #error "I2S stream is currently incompatible with LIN_ADVANCE."
+#endif
@@ -81,7 +81,7 @@ void IRAM_ATTR timer_isr(void *para) {
 * @param timer_num timer number to initialize
 * @param frequency frequency of the timer
 */
-void HAL_timer_start(const uint8_t timer_num, uint32_t frequency) {
+void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency) {
  const tTimerConfig timer = timer_config[timer_num];

  timer_config_t config;
@@ -127,7 +127,7 @@ extern const tTimerConfig timer_config[];
 // Public functions
 // ------------------------

-void HAL_timer_start (const uint8_t timer_num, uint32_t frequency);
+void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency);
 void HAL_timer_set_compare(const uint8_t timer_num, const hal_timer_t count);
 hal_timer_t HAL_timer_get_compare(const uint8_t timer_num);
 hal_timer_t HAL_timer_get_count(const uint8_t timer_num);
@@ -136,5 +136,5 @@ void HAL_timer_enable_interrupt(const uint8_t timer_num);
 void HAL_timer_disable_interrupt(const uint8_t timer_num);
 bool HAL_timer_interrupt_enabled(const uint8_t timer_num);

-#define HAL_timer_isr_prologue(T)
-#define HAL_timer_isr_epilogue(T)
+#define HAL_timer_isr_prologue(T) NOOP
+#define HAL_timer_isr_epilogue(T) NOOP
@@ -0,0 +1,106 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * Copypaste of SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#ifdef ARDUINO_ARCH_ESP32
+
+#include "../../inc/MarlinConfig.h"
+
+#if EITHER(MKS_MINI_12864, FYSETC_MINI_12864_2_1)
+
+#include <U8glib-HAL.h>
+#include "../shared/HAL_SPI.h"
+#include "HAL.h"
+#include "SPI.h"
+
+#if ENABLED(SDSUPPORT)
+  #include "../../sd/cardreader.h"
+  #if ENABLED(ESP3D_WIFISUPPORT)
+    #include "sd_ESP32.h"
+  #endif
+#endif
+
+static SPISettings spiConfig;
+
+
+#ifndef LCD_SPI_SPEED
+  #ifdef SD_SPI_SPEED
+    #define LCD_SPI_SPEED SD_SPI_SPEED    // Assume SPI speed shared with SD
+  #else
+    #define LCD_SPI_SPEED SPI_FULL_SPEED  // Use full speed if SD speed is not supplied
+  #endif
+#endif
+
+uint8_t u8g_eps_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr) {
+  static uint8_t msgInitCount = 2; // Ignore all messages until 2nd U8G_COM_MSG_INIT
+
+  #if ENABLED(PAUSE_LCD_FOR_BUSY_SD)
+    if (card.flag.saving || card.flag.logging || TERN0(ESP3D_WIFISUPPORT, sd_busy_lock == true)) return 0;
+  #endif
+
+  if (msgInitCount) {
+    if (msg == U8G_COM_MSG_INIT) msgInitCount--;
+    if (msgInitCount) return -1;
+  }
+
+  switch (msg) {
+    case U8G_COM_MSG_STOP: break;
+
+    case U8G_COM_MSG_INIT:
+      OUT_WRITE(DOGLCD_CS, HIGH);
+      OUT_WRITE(DOGLCD_A0, HIGH);
+      OUT_WRITE(LCD_RESET_PIN, HIGH);
+      u8g_Delay(5);
+      spiBegin();
+      spiInit(LCD_SPI_SPEED);
+      break;
+
+    case U8G_COM_MSG_ADDRESS:           /* define cmd (arg_val = 0) or data mode (arg_val = 1) */
+      WRITE(DOGLCD_A0, arg_val ? HIGH : LOW);
+      break;
+
+    case U8G_COM_MSG_CHIP_SELECT:       /* arg_val == 0 means HIGH level of U8G_PI_CS */
+      WRITE(DOGLCD_CS, arg_val ? LOW : HIGH);
+      break;
+
+    case U8G_COM_MSG_RESET:
+      WRITE(LCD_RESET_PIN, arg_val);
+      break;
+
+    case U8G_COM_MSG_WRITE_BYTE:
+      spiSend((uint8_t)arg_val);
+      break;
+
+    case U8G_COM_MSG_WRITE_SEQ:
+      uint8_t *ptr = (uint8_t*) arg_ptr;
+      while (arg_val > 0) {
+        spiSend(*ptr++);
+        arg_val--;
+      }
+      break;
+  }
+  return 1;
+}
+
+#endif // EITHER(MKS_MINI_12864, FYSETC_MINI_12864_2_1)
+
+#endif // ARDUINO_ARCH_ESP32
@@ -1,42 +0,0 @@
-/**
- * Marlin 3D Printer Firmware
- * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- *
- * Based on Sprinter and grbl.
- * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- *
- */
-#ifdef ARDUINO_ARCH_ESP32
-
-#include "../../inc/MarlinConfig.h"
-
-#if ENABLED(USE_WATCHDOG)
-
-#define WDT_TIMEOUT_US TERN(WATCHDOG_DURATION_8S, 8000000, 4000000) // 4 or 8 second timeout
-
-#include "watchdog.h"
-
-void watchdogSetup() {
-  // do whatever. don't remove this function.
-}
-
-void watchdog_init() {
-  // TODO
-}
-
-#endif // USE_WATCHDOG
-
-#endif // ARDUINO_ARCH_ESP32
@@ -28,6 +28,7 @@
 #endif

 #include HAL_PATH(.,HAL.h)
+extern MarlinHAL hal;

 #define HAL_ADC_RANGE _BV(HAL_ADC_RESOLUTION)

@@ -44,7 +45,3 @@
 #ifndef PGMSTR
  #define PGMSTR(NAM,STR) const char NAM[] = STR
 #endif
-
-inline void watchdog_refresh() {
-  TERN_(USE_WATCHDOG, HAL_watchdog_refresh());
-}
@@ -24,6 +24,10 @@
 #include "../../inc/MarlinConfig.h"
 #include "../shared/Delay.h"

+// ------------------------
+// Serial ports
+// ------------------------
+
 MSerialT usb_serial(TERN0(EMERGENCY_PARSER, true));

 // U8glib required functions
@@ -37,42 +41,21 @@ extern "C" {
 //************************//

 // return free heap space
-int freeMemory() {
-  return 0;
-}
+int freeMemory() { return 0; }

 // ------------------------
 // ADC
 // ------------------------

-void HAL_adc_init() {
+uint8_t MarlinHAL::active_ch = 0;

-}
-
-void HAL_adc_enable_channel(const uint8_t ch) {
-
-}
-
-uint8_t active_ch = 0;
-void HAL_adc_start_conversion(const uint8_t ch) {
-  active_ch = ch;
-}
-
-bool HAL_adc_finished() {
-  return true;
-}
-
-uint16_t HAL_adc_get_result() {
-  pin_t pin = analogInputToDigitalPin(active_ch);
+uint16_t MarlinHAL::adc_value() {
+  const pin_t pin = analogInputToDigitalPin(active_ch);
  if (!VALID_PIN(pin)) return 0;
-  uint16_t data = ((Gpio::get(pin) >> 2) & 0x3FF);
+  const uint16_t data = ((Gpio::get(pin) >> 2) & 0x3FF);
  return data;    // return 10bit value as Marlin expects
 }

-void HAL_pwm_init() {
-
-}
-
-void HAL_reboot() { /* Reset the application state and GPIO */ }
+void MarlinHAL::reboot() { /* Reset the application state and GPIO */ }

 #endif // __PLAT_LINUX__
@@ -21,25 +21,42 @@
 */
 #pragma once

-#define CPU_32_BIT
+#include "../../inc/MarlinConfigPre.h"

-#define F_CPU 100000000UL
-#define SystemCoreClock F_CPU
 #include <iostream>
 #include <stdint.h>
 #include <stdarg.h>
-
 #undef min
 #undef max
-
 #include <algorithm>

-void _printf (const  char *format, ...);
+#include "hardware/Clock.h"
+#include "../shared/Marduino.h"
+#include "../shared/math_32bit.h"
+#include "../shared/HAL_SPI.h"
+#include "fastio.h"
+#include "serial.h"
+
+// ------------------------
+// Defines
+// ------------------------
+
+#define CPU_32_BIT
+#define SHARED_SERVOS HAS_SERVOS  // Use shared/servos.cpp
+
+#define F_CPU 100000000UL
+#define SystemCoreClock F_CPU
+
+#define DELAY_CYCLES(x) Clock::delayCycles(x)
+
+#define CPU_ST7920_DELAY_1 600
+#define CPU_ST7920_DELAY_2 750
+#define CPU_ST7920_DELAY_3 750
+
+void _printf(const  char *format, ...);
 void _putc(uint8_t c);
 uint8_t _getc();

-//extern "C" volatile uint32_t _millis;
-
 //arduino: Print.h
 #define DEC 10
 #define HEX 16
@@ -49,36 +66,27 @@ uint8_t _getc();
 #define B01 1
 #define B10 2

-#include "hardware/Clock.h"
-
-#include "../shared/Marduino.h"
-#include "../shared/math_32bit.h"
-#include "../shared/HAL_SPI.h"
-#include "fastio.h"
-#include "watchdog.h"
-#include "serial.h"
-
-#define SHARED_SERVOS HAS_SERVOS
+// ------------------------
+// Serial ports
+// ------------------------

 extern MSerialT usb_serial;
 #define MYSERIAL1 usb_serial

-#define CPU_ST7920_DELAY_1 600
-#define CPU_ST7920_DELAY_2 750
-#define CPU_ST7920_DELAY_3 750
-
 //
 // Interrupts
 //
 #define CRITICAL_SECTION_START()
 #define CRITICAL_SECTION_END()
-#define ISRS_ENABLED()
-#define ENABLE_ISRS()
-#define DISABLE_ISRS()

-inline void HAL_init() {}
+// ADC
+#define HAL_ADC_VREF           5.0
+#define HAL_ADC_RESOLUTION    10
+
+// ------------------------
+// Class Utilities
+// ------------------------

-// Utility functions
 #pragma GCC diagnostic push
 #if GCC_VERSION <= 50000
  #pragma GCC diagnostic ignored "-Wunused-function"
@@ -88,29 +96,70 @@ int freeMemory();

 #pragma GCC diagnostic pop

-// ADC
-#define HAL_ADC_VREF           5.0
-#define HAL_ADC_RESOLUTION    10
-#define HAL_ANALOG_SELECT(ch) HAL_adc_enable_channel(ch)
-#define HAL_START_ADC(ch)     HAL_adc_start_conversion(ch)
-#define HAL_READ_ADC()        HAL_adc_get_result()
-#define HAL_ADC_READY()       true
+// ------------------------
+// MarlinHAL Class
+// ------------------------

-void HAL_adc_init();
-void HAL_adc_enable_channel(const uint8_t ch);
-void HAL_adc_start_conversion(const uint8_t ch);
-uint16_t HAL_adc_get_result();
+class MarlinHAL {
+public:

-// PWM
-inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
+  // Earliest possible init, before setup()
+  MarlinHAL() {}

-// Reset source
-inline void HAL_clear_reset_source(void) {}
-inline uint8_t HAL_get_reset_source(void) { return RST_POWER_ON; }
+  // Watchdog
+  static void watchdog_init() {}
+  static void watchdog_refresh() {}

-void HAL_reboot(); // Reset the application state and GPIO
+  static void init() {}        // Called early in setup()
+  static void init_board() {}  // Called less early in setup()
+  static void reboot();        // Reset the application state and GPIO

-/* ---------------- Delay in cycles */
-FORCE_INLINE static void DELAY_CYCLES(uint64_t x) {
-  Clock::delayCycles(x);
-}
+  // Interrupts
+  static bool isr_state() { return true; }
+  static void isr_on()  {}
+  static void isr_off() {}
+
+  static void delay_ms(const int ms) { _delay_ms(ms); }
+
+  // Tasks, called from idle()
+  static void idletask() {}
+
+  // Reset
+  static constexpr uint8_t reset_reason = RST_POWER_ON;
+  static uint8_t get_reset_source() { return reset_reason; }
+  static void clear_reset_source() {}
+
+  // Free SRAM
+  static int freeMemory() { return ::freeMemory(); }
+
+  //
+  // ADC Methods
+  //
+
+  static uint8_t active_ch;
+
+  // Called by Temperature::init once at startup
+  static void adc_init() {}
+
+  // Called by Temperature::init for each sensor at startup
+  static void adc_enable(const uint8_t) {}
+
+  // Begin ADC sampling on the given channel
+  static void adc_start(const uint8_t ch) { active_ch = ch; }
+
+  // Is the ADC ready for reading?
+  static bool adc_ready() { return true; }
+
+  // The current value of the ADC register
+  static uint16_t adc_value();
+
+  /**
+   * Set the PWM duty cycle for the pin to the given value.
+   * No option to change the resolution or invert the duty cycle.
+   */
+  static void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) {
+    analogWrite(pin, v);
+  }
+
+  static void set_pwm_frequency(const pin_t, int) {}
+};
@@ -31,9 +31,7 @@ void cli() { } // Disable
 void sei() { } // Enable

 // Time functions
-void _delay_ms(const int delay_ms) {
-  delay(delay_ms);
-}
+void _delay_ms(const int ms) { delay(ms); }

 uint32_t millis() {
  return (uint32_t)Clock::millis();
@@ -69,12 +69,12 @@ bool PersistentStore::write_data(int &pos, const uint8_t *value, size_t size, ui
  std::size_t bytes_written = 0;

  for (std::size_t i = 0; i < size; i++) {
-    buffer[pos+i] = value[i];
-    bytes_written ++;
+    buffer[pos + i] = value[i];
+    bytes_written++;
  }

  crc16(crc, value, size);
-  pos = pos + size;
+  pos += size;
  return (bytes_written != size);  // return true for any error
 }

@@ -82,21 +82,21 @@ bool PersistentStore::read_data(int &pos, uint8_t *value, const size_t size, uin
  std::size_t bytes_read = 0;
  if (writing) {
    for (std::size_t i = 0; i < size; i++) {
-      value[i] = buffer[pos+i];
-      bytes_read ++;
+      value[i] = buffer[pos + i];
+      bytes_read++;
    }
    crc16(crc, value, size);
  }
  else {
    uint8_t temp[size];
    for (std::size_t i = 0; i < size; i++) {
-      temp[i] = buffer[pos+i];
-      bytes_read ++;
+      temp[i] = buffer[pos + i];
+      bytes_read++;
    }
    crc16(crc, temp, size);
  }

-  pos = pos + size;
+  pos += size;
  return bytes_read != size;  // return true for any error
 }

@@ -26,8 +26,8 @@
 struct LowpassFilter {
  uint64_t data_delay = 0;
  uint16_t update(uint16_t value) {
-    data_delay = data_delay - (data_delay >> 6) + value;
-    return (uint16_t)(data_delay >> 6);
+    data_delay += value - (data_delay >> 6);
+    return uint16_t(data_delay >> 6);
  }
 };

@@ -59,10 +59,9 @@ typedef uint8_t byte;
 #endif

 #define sq(v) ((v) * (v))
-#define square(v) sq(v)
 #define constrain(value, arg_min, arg_max) ((value) < (arg_min) ? (arg_min) :((value) > (arg_max) ? (arg_max) : (value)))

-//Interrupts
+// Interrupts
 void cli(); // Disable
 void sei(); // Enable
 void attachInterrupt(uint32_t pin, void (*callback)(), uint32_t mode);
@@ -74,8 +73,8 @@ extern "C" {
 }

 // Time functions
-extern "C" void delay(const int milis);
-void _delay_ms(const int delay);
+extern "C" void delay(const int ms);
+void _delay_ms(const int ms);
 void delayMicroseconds(unsigned long);
 uint32_t millis();

@@ -92,5 +92,5 @@ void HAL_timer_enable_interrupt(const uint8_t timer_num);
 void HAL_timer_disable_interrupt(const uint8_t timer_num);
 bool HAL_timer_interrupt_enabled(const uint8_t timer_num);

-#define HAL_timer_isr_prologue(T)
-#define HAL_timer_isr_epilogue(T)
+#define HAL_timer_isr_prologue(T) NOOP
+#define HAL_timer_isr_epilogue(T) NOOP
@@ -1,37 +0,0 @@
-/**
- * Marlin 3D Printer Firmware
- * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- *
- * Based on Sprinter and grbl.
- * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- *
- */
-#ifdef __PLAT_LINUX__
-
-#include "../../inc/MarlinConfig.h"
-
-#if ENABLED(USE_WATCHDOG)
-
-#include "watchdog.h"
-
-#define WDT_TIMEOUT_US TERN(WATCHDOG_DURATION_8S, 8000000, 4000000) // 4 or 8 second timeout
-
-void watchdog_init() {}
-void HAL_watchdog_refresh() {}
-
-#endif
-
-#endif // __PLAT_LINUX__
@@ -25,13 +25,9 @@
 #include "../shared/Delay.h"
 #include "../../../gcode/parser.h"

-#if ENABLED(USE_WATCHDOG)
-  #include "watchdog.h"
-#endif
-
 DefaultSerial1 USBSerial(false, UsbSerial);

-uint32_t HAL_adc_reading = 0;
+uint32_t MarlinHAL::adc_result = 0;

 // U8glib required functions
 extern "C" {
@@ -41,8 +37,6 @@ extern "C" {
  void u8g_Delay(uint16_t val)       { delay(val); }
 }

-//************************//
-
 // return free heap space
 int freeMemory() {
  char stack_end;
@@ -54,7 +48,71 @@ int freeMemory() {
  return result;
 }

-// scan command line for code
+void MarlinHAL::reboot() { NVIC_SystemReset(); }
+
+uint8_t MarlinHAL::get_reset_source() {
+  #if ENABLED(USE_WATCHDOG)
+    if (watchdog_timed_out()) return RST_WATCHDOG;
+  #endif
+  return RST_POWER_ON;
+}
+
+void MarlinHAL::clear_reset_source() { watchdog_clear_timeout_flag(); }
+
+void flashFirmware(const int16_t) {
+  delay(500);          // Give OS time to disconnect
+  USB_Connect(false);  // USB clear connection
+  delay(1000);         // Give OS time to notice
+  hal.reboot();
+}
+
+#if ENABLED(USE_WATCHDOG)
+
+  #include <lpc17xx_wdt.h>
+
+  #define WDT_TIMEOUT_US TERN(WATCHDOG_DURATION_8S, 8000000, 4000000) // 4 or 8 second timeout
+
+  void MarlinHAL::watchdog_init() {
+    #if ENABLED(WATCHDOG_RESET_MANUAL)
+      // We enable the watchdog timer, but only for the interrupt.
+
+      // Configure WDT to only trigger an interrupt
+      // Disable WDT interrupt (just in case, to avoid triggering it!)
+      NVIC_DisableIRQ(WDT_IRQn);
+
+      // We NEED memory barriers to ensure Interrupts are actually disabled!
+      // ( https://dzone.com/articles/nvic-disabling-interrupts-on-arm-cortex-m-and-the )
+      __DSB();
+      __ISB();
+
+      // Configure WDT to only trigger an interrupt
+      // Initialize WDT with the given parameters
+      WDT_Init(WDT_CLKSRC_IRC, WDT_MODE_INT_ONLY);
+
+      // Configure and enable WDT interrupt.
+      NVIC_ClearPendingIRQ(WDT_IRQn);
+      NVIC_SetPriority(WDT_IRQn, 0); // Use highest priority, so we detect all kinds of lockups
+      NVIC_EnableIRQ(WDT_IRQn);
+    #else
+      WDT_Init(WDT_CLKSRC_IRC, WDT_MODE_RESET);
+    #endif
+    WDT_Start(WDT_TIMEOUT_US);
+  }
+
+  void MarlinHAL::watchdog_refresh() {
+    WDT_Feed();
+    #if DISABLED(PINS_DEBUGGING) && PIN_EXISTS(LED)
+      TOGGLE(LED_PIN);  // heartbeat indicator
+    #endif
+  }
+
+  // Timeout state
+  bool MarlinHAL::watchdog_timed_out() { return TEST(WDT_ReadTimeOutFlag(), 0); }
+  void MarlinHAL::watchdog_clear_timeout_flag() { WDT_ClrTimeOutFlag(); }
+
+#endif // USE_WATCHDOG
+
+// For M42/M43, scan command line for pin code
 //   return index into pin map array if found and the pin is valid.
 //   return dval if not found or not a valid pin.
 int16_t PARSED_PIN_INDEX(const char code, const int16_t dval) {
@@ -63,24 +121,4 @@ int16_t PARSED_PIN_INDEX(const char code, const int16_t dval) {
  return ind > -1 ? ind : dval;
 }

-void flashFirmware(const int16_t) {
-  delay(500);          // Give OS time to disconnect
-  USB_Connect(false);  // USB clear connection
-  delay(1000);         // Give OS time to notice
-  HAL_reboot();
-}
-
-void HAL_clear_reset_source(void) {
-  TERN_(USE_WATCHDOG, watchdog_clear_timeout_flag());
-}
-
-uint8_t HAL_get_reset_source(void) {
-  #if ENABLED(USE_WATCHDOG)
-    if (watchdog_timed_out()) return RST_WATCHDOG;
-  #endif
-  return RST_POWER_ON;
-}
-
-void HAL_reboot() { NVIC_SystemReset(); }
-
 #endif // TARGET_LPC1768
@@ -28,8 +28,6 @@

 #define CPU_32_BIT

-void HAL_init();
-
 #include <stdint.h>
 #include <stdarg.h>
 #include <algorithm>
@@ -40,19 +38,15 @@ extern "C" volatile uint32_t _millis;
 #include "../shared/math_32bit.h"
 #include "../shared/HAL_SPI.h"
 #include "fastio.h"
-#include "watchdog.h"
 #include "MarlinSerial.h"

 #include <adc.h>
 #include <pinmapping.h>
 #include <CDCSerial.h>

-//
-// Default graphical display delays
-//
-#define CPU_ST7920_DELAY_1 600
-#define CPU_ST7920_DELAY_2 750
-#define CPU_ST7920_DELAY_3 750
+// ------------------------
+// Serial ports
+// ------------------------

 typedef ForwardSerial1Class< decltype(UsbSerial) > DefaultSerial1;
 extern DefaultSerial1 USBSerial;
@@ -114,26 +108,12 @@ extern DefaultSerial1 USBSerial;
 //
 // Interrupts
 //
-#define CRITICAL_SECTION_START()  uint32_t primask = __get_PRIMASK(); __disable_irq()
-#define CRITICAL_SECTION_END()    if (!primask) __enable_irq()
-#define ISRS_ENABLED() (!__get_PRIMASK())
-#define ENABLE_ISRS()  __enable_irq()
-#define DISABLE_ISRS() __disable_irq()
+
+#define CRITICAL_SECTION_START()  const bool irqon = !__get_PRIMASK(); __disable_irq()
+#define CRITICAL_SECTION_END()    if (irqon) __enable_irq()

 //
-// Utility functions
-//
-#pragma GCC diagnostic push
-#if GCC_VERSION <= 50000
-  #pragma GCC diagnostic ignored "-Wunused-function"
-#endif
-
-int freeMemory();
-
-#pragma GCC diagnostic pop
-
-//
-// ADC API
+// ADC
 //

 #define ADC_MEDIAN_FILTER_SIZE (23) // Higher values increase step delay (phase shift),
@@ -152,20 +132,9 @@ int freeMemory();
 #define HAL_ADC_RESOLUTION     12   // 15 bit maximum, raw temperature is stored as int16_t
 #define HAL_ADC_FILTERED            // Disable oversampling done in Marlin as ADC values already filtered in HAL

-using FilteredADC = LPC176x::ADC<ADC_LOWPASS_K_VALUE, ADC_MEDIAN_FILTER_SIZE>;
-extern uint32_t HAL_adc_reading;
-[[gnu::always_inline]] inline void HAL_adc_start_conversion(const pin_t pin) {
-  HAL_adc_reading = FilteredADC::read(pin) >> (16 - HAL_ADC_RESOLUTION); // returns 16bit value, reduce to required bits
-}
-[[gnu::always_inline]] inline uint16_t HAL_adc_get_result() {
-  return HAL_adc_reading;
-}
-
-#define HAL_adc_init()
-#define HAL_ANALOG_SELECT(pin) FilteredADC::enable_channel(pin)
-#define HAL_START_ADC(pin)     HAL_adc_start_conversion(pin)
-#define HAL_READ_ADC()         HAL_adc_get_result()
-#define HAL_ADC_READY()        (true)
+//
+// Pin Mapping for M42, M43, M226
+//

 // Test whether the pin is valid
 constexpr bool VALID_PIN(const pin_t pin) {
@@ -192,32 +161,107 @@ int16_t PARSED_PIN_INDEX(const char code, const int16_t dval);
 // P0.6 thru P0.9 are for the onboard SD card
 #define HAL_SENSITIVE_PINS P0_06, P0_07, P0_08, P0_09,

-#define HAL_IDLETASK 1
-void HAL_idletask();
+// ------------------------
+// Defines
+// ------------------------

 #define PLATFORM_M997_SUPPORT
 void flashFirmware(const int16_t);

 #define HAL_CAN_SET_PWM_FREQ   // This HAL supports PWM Frequency adjustment

-/**
- * set_pwm_frequency
- *  Set the frequency of the timer corresponding to the provided pin
- *  All Hardware PWM pins run at the same frequency and all
- *  Software PWM pins run at the same frequency
- */
-void set_pwm_frequency(const pin_t pin, const uint16_t f_desired);
+// Default graphical display delays
+#define CPU_ST7920_DELAY_1 600
+#define CPU_ST7920_DELAY_2 750
+#define CPU_ST7920_DELAY_3 750

-/**
- * set_pwm_duty
- *  Set the PWM duty cycle of the provided pin to the provided value
- *  Optionally allows inverting the duty cycle [default = false]
- *  Optionally allows changing the maximum size of the provided value to enable finer PWM duty control [default = 255]
- */
-void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size=255, const bool invert=false);
+// ------------------------
+// Free Memory Accessor
+// ------------------------

-// Reset source
-void HAL_clear_reset_source(void);
-uint8_t HAL_get_reset_source(void);
+#pragma GCC diagnostic push
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif

-void HAL_reboot();
+int freeMemory();
+
+#pragma GCC diagnostic pop
+
+// ------------------------
+// MarlinHAL Class
+// ------------------------
+
+class MarlinHAL {
+public:
+
+  // Earliest possible init, before setup()
+  MarlinHAL() {}
+
+  static void init();          // Called early in setup()
+  static void init_board() {}  // Called less early in setup()
+  static void reboot();        // Restart the firmware from 0x0
+
+  // Interrupts
+  static bool isr_state() { return !__get_PRIMASK(); }
+  static void isr_on()  { __enable_irq(); }
+  static void isr_off() { __disable_irq(); }
+
+  static void delay_ms(const int ms) { _delay_ms(ms); }
+
+  // Watchdog
+  static void watchdog_init() IF_DISABLED(USE_WATCHDOG, {});
+  static void watchdog_refresh() IF_DISABLED(USE_WATCHDOG, {});
+  static bool watchdog_timed_out() IF_DISABLED(USE_WATCHDOG, { return false; });
+  static void watchdog_clear_timeout_flag() IF_DISABLED(USE_WATCHDOG, {});
+
+  // Tasks, called from idle()
+  static void idletask();
+
+  // Reset
+  static uint8_t get_reset_source();
+  static void clear_reset_source();
+
+  // Free SRAM
+  static int freeMemory() { return ::freeMemory(); }
+
+  //
+  // ADC Methods
+  //
+
+  using FilteredADC = LPC176x::ADC<ADC_LOWPASS_K_VALUE, ADC_MEDIAN_FILTER_SIZE>;
+
+  // Called by Temperature::init once at startup
+  static void adc_init() {}
+
+  // Called by Temperature::init for each sensor at startup
+  static void adc_enable(const pin_t pin) {
+    FilteredADC::enable_channel(pin);
+  }
+
+  // Begin ADC sampling on the given pin. Called from Temperature::isr!
+  static uint32_t adc_result;
+  static void adc_start(const pin_t pin) {
+    adc_result = FilteredADC::read(pin) >> (16 - HAL_ADC_RESOLUTION); // returns 16bit value, reduce to required bits
+  }
+
+  // Is the ADC ready for reading?
+  static bool adc_ready() { return true; }
+
+  // The current value of the ADC register
+  static uint16_t adc_value() { return uint16_t(adc_result); }
+
+  /**
+   * Set the PWM duty cycle for the pin to the given value.
+   * Optionally invert the duty cycle [default = false]
+   * Optionally change the scale of the provided value to enable finer PWM duty control [default = 255]
+   */
+  static void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size=255, const bool invert=false);
+
+  /**
+   * Set the frequency of the timer corresponding to the provided pin
+   * All Hardware PWM pins will run at the same frequency and
+   * All Software PWM pins will run at the same frequency
+   */
+  static void set_pwm_frequency(const pin_t pin, const uint16_t f_desired);
+};
@@ -26,7 +26,7 @@

 #if ENABLED(POSTMORTEM_DEBUGGING)

-#include "../shared/HAL_MinSerial.h"
+#include "../shared/MinSerial.h"
 #include <debug_frmwrk.h>

 static void TX(char c) { _DBC(c); }
@@ -65,4 +65,5 @@ class libServo: public Servo {
  }
 };

-#define HAL_SERVO_LIB libServo
+class libServo;
+typedef libServo hal_servo_t;
@@ -34,7 +34,7 @@
 #include "../shared/eeprom_api.h"

 #ifndef MARLIN_EEPROM_SIZE
-  #define MARLIN_EEPROM_SIZE           0x8000 // 32KB‬
+  #define MARLIN_EEPROM_SIZE           0x8000 // 32K
 #endif
 size_t PersistentStore::capacity()    { return MARLIN_EEPROM_SIZE; }

@@ -155,4 +155,37 @@ void setup_endstop_interrupts() {
    #endif
    _ATTACH(K_MIN_PIN);
  #endif
+  #if HAS_U_MAX
+    #if !LPC1768_PIN_INTERRUPT_M(U_MAX_PIN)
+      #error "U_MAX_PIN is not INTERRUPT-capable."
+    #endif
+    _ATTACH(U_MAX_PIN);
+  #elif HAS_U_MIN
+    #if !LPC1768_PIN_INTERRUPT_M(U_MIN_PIN)
+      #error "U_MIN_PIN is not INTERRUPT-capable."
+    #endif
+    _ATTACH(U_MIN_PIN);
+  #endif
+  #if HAS_V_MAX
+    #if !LPC1768_PIN_INTERRUPT_M(V_MAX_PIN)
+      #error "V_MAX_PIN is not INTERRUPT-capable."
+    #endif
+    _ATTACH(V_MAX_PIN);
+  #elif HAS_V_MIN
+    #if !LPC1768_PIN_INTERRUPT_M(V_MIN_PIN)
+      #error "V_MIN_PIN is not INTERRUPT-capable."
+    #endif
+    _ATTACH(V_MIN_PIN);
+  #endif
+  #if HAS_W_MAX
+    #if !LPC1768_PIN_INTERRUPT_M(W_MAX_PIN)
+      #error "W_MAX_PIN is not INTERRUPT-capable."
+    #endif
+    _ATTACH(W_MAX_PIN);
+  #elif HAS_W_MIN
+    #if !LPC1768_PIN_INTERRUPT_M(W_MIN_PIN)
+      #error "W_MIN_PIN is not INTERRUPT-capable."
+    #endif
+    _ATTACH(W_MIN_PIN);
+  #endif
 }
@@ -21,16 +21,16 @@
 */
 #ifdef TARGET_LPC1768

-#include "../../inc/MarlinConfigPre.h"
+#include "../../inc/MarlinConfig.h"
 #include <pwm.h>

-void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
+void MarlinHAL::set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
  if (!LPC176x::pin_is_valid(pin)) return;
  if (LPC176x::pwm_attach_pin(pin))
    LPC176x::pwm_write_ratio(pin, invert ? 1.0f - (float)v / v_size : (float)v / v_size);  // map 1-254 onto PWM range
 }

-void set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {
+void MarlinHAL::set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {
  LPC176x::pwm_set_frequency(pin, f_desired);
 }

@@ -29,6 +29,6 @@

 // LPC1768 boards seem to lose steps when saving to EEPROM during print (issue #20785)
 // TODO: Which other boards are incompatible?
-#if defined(MCU_LPC1768) && PRINTCOUNTER_SAVE_INTERVAL > 0
+#if defined(MCU_LPC1768) && ENABLED(FLASH_EEPROM_EMULATION) && PRINTCOUNTER_SAVE_INTERVAL > 0
  #define PRINTCOUNTER_SYNC 1
 #endif
@@ -29,7 +29,7 @@

 #include "../../../inc/MarlinConfigPre.h"

-#if MB(MKS_SBASE)
+#if ENABLED(DIGIPOT_MCP4451) && MB(MKS_SBASE)

 #ifdef __cplusplus
  extern "C" {
@@ -37,35 +37,6 @@

 #include "digipot_mcp4451_I2C_routines.h"

-// These two routines are exact copies of the lpc17xx_i2c.c routines.  Couldn't link to
-// to the lpc17xx_i2c.c routines so had to copy them into this file & rename them.
-
-static uint32_t _I2C_Start(LPC_I2C_TypeDef *I2Cx) {
-  // Reset STA, STO, SI
-  I2Cx->I2CONCLR = I2C_I2CONCLR_SIC|I2C_I2CONCLR_STOC|I2C_I2CONCLR_STAC;
-
-  // Enter to Master Transmitter mode
-  I2Cx->I2CONSET = I2C_I2CONSET_STA;
-
-  // Wait for complete
-  while (!(I2Cx->I2CONSET & I2C_I2CONSET_SI));
-  I2Cx->I2CONCLR = I2C_I2CONCLR_STAC;
-  return (I2Cx->I2STAT & I2C_STAT_CODE_BITMASK);
-}
-
-static void _I2C_Stop(LPC_I2C_TypeDef *I2Cx) {
-  // Make sure start bit is not active
-  if (I2Cx->I2CONSET & I2C_I2CONSET_STA)
-    I2Cx->I2CONCLR = I2C_I2CONCLR_STAC;
-
-  I2Cx->I2CONSET = I2C_I2CONSET_STO|I2C_I2CONSET_AA;
-  I2Cx->I2CONCLR = I2C_I2CONCLR_SIC;
-}
-
-I2C_M_SETUP_Type transferMCfg;
-
-#define I2C_status (LPC_I2C1->I2STAT & I2C_STAT_CODE_BITMASK)
-
 uint8_t digipot_mcp4451_start(uint8_t sla) {  // send slave address and write bit
  // Sometimes TX data ACK or NAK status is returned.  That mean the start state didn't
  // happen which means only the value of the slave address was send.  Keep looping until
@@ -102,5 +73,5 @@ uint8_t digipot_mcp4451_send_byte(uint8_t data) {
  }
 #endif

-#endif // MB(MKS_SBASE)
+#endif // DIGIPOT_MCP4451 && MKS_SBASE
 #endif // TARGET_LPC1768
@@ -63,6 +63,32 @@ void configure_i2c(const uint8_t clock_option) {
  I2C_Cmd(I2CDEV_M, I2C_MASTER_MODE, ENABLE);
 }

+//////////////////////////////////////////////////////////////////////////////////////
+// These two routines are exact copies of the lpc17xx_i2c.c routines.  Couldn't link to
+// to the lpc17xx_i2c.c routines so had to copy them into this file & rename them.
+
+uint32_t _I2C_Start(LPC_I2C_TypeDef *I2Cx) {
+  // Reset STA, STO, SI
+  I2Cx->I2CONCLR = I2C_I2CONCLR_SIC|I2C_I2CONCLR_STOC|I2C_I2CONCLR_STAC;
+
+  // Enter to Master Transmitter mode
+  I2Cx->I2CONSET = I2C_I2CONSET_STA;
+
+  // Wait for complete
+  while (!(I2Cx->I2CONSET & I2C_I2CONSET_SI));
+  I2Cx->I2CONCLR = I2C_I2CONCLR_STAC;
+  return (I2Cx->I2STAT & I2C_STAT_CODE_BITMASK);
+}
+
+void _I2C_Stop(LPC_I2C_TypeDef *I2Cx) {
+  /* Make sure start bit is not active */
+  if (I2Cx->I2CONSET & I2C_I2CONSET_STA)
+    I2Cx->I2CONCLR = I2C_I2CONCLR_STAC;
+
+  I2Cx->I2CONSET = I2C_I2CONSET_STO|I2C_I2CONSET_AA;
+  I2Cx->I2CONCLR = I2C_I2CONCLR_SIC;
+}
+
 #ifdef __cplusplus
  }
 #endif
@@ -51,6 +51,11 @@

 void configure_i2c(const uint8_t clock_option);

+uint32_t _I2C_Start(LPC_I2C_TypeDef *I2Cx);
+void _I2C_Stop(LPC_I2C_TypeDef *I2Cx);
+
+#define I2C_status (LPC_I2C1->I2STAT & I2C_STAT_CODE_BITMASK)
+
 #ifdef __cplusplus
  }
 #endif
@@ -48,7 +48,7 @@ void SysTick_Callback() { disk_timerproc(); }

 TERN_(POSTMORTEM_DEBUGGING, extern void install_min_serial());

-void HAL_init() {
+void MarlinHAL::init() {

  // Init LEDs
  #if PIN_EXISTS(LED)
@@ -130,7 +130,7 @@ void HAL_init() {
  const millis_t usb_timeout = millis() + 2000;
  while (!USB_Configuration && PENDING(millis(), usb_timeout)) {
    delay(50);
-    HAL_idletask();
+    idletask();
    #if PIN_EXISTS(LED)
      TOGGLE(LED_PIN);     // Flash quickly during USB initialization
    #endif
@@ -142,7 +142,7 @@ void HAL_init() {
 }

 // HAL idle task
-void HAL_idletask() {
+void MarlinHAL::idletask() {
  #if HAS_SHARED_MEDIA
    // If Marlin is using the SD card we need to lock it to prevent access from
    // a PC via USB.
@@ -170,4 +170,4 @@ FORCE_INLINE static void HAL_timer_isr_prologue(const uint8_t timer_num) {
  }
 }

-#define HAL_timer_isr_epilogue(T)
+#define HAL_timer_isr_epilogue(T) NOOP
@@ -36,40 +36,7 @@ extern int millis();

 //////////////////////////////////////////////////////////////////////////////////////

-// These two routines are exact copies of the lpc17xx_i2c.c routines.  Couldn't link to
-// to the lpc17xx_i2c.c routines so had to copy them into this file & rename them.
-
-static uint32_t _I2C_Start(LPC_I2C_TypeDef *I2Cx) {
-  // Reset STA, STO, SI
-  I2Cx->I2CONCLR = I2C_I2CONCLR_SIC|I2C_I2CONCLR_STOC|I2C_I2CONCLR_STAC;
-
-  // Enter to Master Transmitter mode
-  I2Cx->I2CONSET = I2C_I2CONSET_STA;
-
-  // Wait for complete
-  while (!(I2Cx->I2CONSET & I2C_I2CONSET_SI));
-  I2Cx->I2CONCLR = I2C_I2CONCLR_STAC;
-  return (I2Cx->I2STAT & I2C_STAT_CODE_BITMASK);
-}
-
-static void _I2C_Stop (LPC_I2C_TypeDef *I2Cx) {
-  /* Make sure start bit is not active */
-  if (I2Cx->I2CONSET & I2C_I2CONSET_STA)
-    I2Cx->I2CONCLR = I2C_I2CONCLR_STAC;
-
-  I2Cx->I2CONSET = I2C_I2CONSET_STO|I2C_I2CONSET_AA;
-  I2Cx->I2CONCLR = I2C_I2CONCLR_SIC;
-}
-
-//////////////////////////////////////////////////////////////////////////////////////
-
-#define I2CDEV_S_ADDR   0x78  // from SSD1306  //actual address is 0x3C - shift left 1 with LSB set to 0 to indicate write
-
-#define BUFFER_SIZE                     0x1  // only do single byte transfers with LCDs
-
-I2C_M_SETUP_Type transferMCfg;
-
-#define I2C_status (LPC_I2C1->I2STAT & I2C_STAT_CODE_BITMASK)
+#define I2CDEV_S_ADDR   0x78  // From SSD1306 (actual address is 0x3C - shift left 1 with LSB set to 0 to indicate write)

 // Send slave address and write bit
 uint8_t u8g_i2c_start(const uint8_t sla) {
@@ -115,7 +82,6 @@ uint8_t u8g_i2c_send_byte(uint8_t data) {
 void u8g_i2c_stop() {
 }

-
 #ifdef __cplusplus
  }
 #endif
@@ -9,119 +9,127 @@ from __future__ import print_function
 import pioutil
 if pioutil.is_pio_build():

-	target_filename = "FIRMWARE.CUR"
-	target_drive = "REARM"
+    target_filename = "FIRMWARE.CUR"
+    target_drive = "REARM"

-	import os,getpass,platform
+    import platform

-	current_OS = platform.system()
-	Import("env")
+    current_OS = platform.system()
+    Import("env")

-	def print_error(e):
-		print('\nUnable to find destination disk (%s)\n' \
-			  'Please select it in platformio.ini using the upload_port keyword ' \
-			  '(https://docs.platformio.org/en/latest/projectconf/section_env_upload.html) ' \
-			  'or copy the firmware (.pio/build/%s/firmware.bin) manually to the appropriate disk\n' \
-			  %(e, env.get('PIOENV')))
+    def print_error(e):
+        print('\nUnable to find destination disk (%s)\n' \
+              'Please select it in platformio.ini using the upload_port keyword ' \
+              '(https://docs.platformio.org/en/latest/projectconf/section_env_upload.html) ' \
+              'or copy the firmware (.pio/build/%s/firmware.bin) manually to the appropriate disk\n' \
+              %(e, env.get('PIOENV')))

-	def before_upload(source, target, env):
-		try:
-			#
-			# Find a disk for upload
-			#
-			upload_disk = 'Disk not found'
-			target_file_found = False
-			target_drive_found = False
-			if current_OS == 'Windows':
-				#
-				# platformio.ini will accept this for a Windows upload port designation: 'upload_port = L:'
-				#   Windows - doesn't care about the disk's name, only cares about the drive letter
-				import subprocess,string
-				from ctypes import windll
+    def before_upload(source, target, env):
+        try:
+            from pathlib import Path
+            #
+            # Find a disk for upload
+            #
+            upload_disk = 'Disk not found'
+            target_file_found = False
+            target_drive_found = False
+            if current_OS == 'Windows':
+                #
+                # platformio.ini will accept this for a Windows upload port designation: 'upload_port = L:'
+                #   Windows - doesn't care about the disk's name, only cares about the drive letter
+                import subprocess,string
+                from ctypes import windll
+                from pathlib import PureWindowsPath

-				# getting list of drives
-				# https://stackoverflow.com/questions/827371/is-there-a-way-to-list-all-the-available-drive-letters-in-python
-				drives = []
-				bitmask = windll.kernel32.GetLogicalDrives()
-				for letter in string.ascii_uppercase:
-					if bitmask & 1:
-						drives.append(letter)
-					bitmask >>= 1
+                # getting list of drives
+                # https://stackoverflow.com/questions/827371/is-there-a-way-to-list-all-the-available-drive-letters-in-python
+                drives = []
+                bitmask = windll.kernel32.GetLogicalDrives()
+                for letter in string.ascii_uppercase:
+                    if bitmask & 1:
+                        drives.append(letter)
+                    bitmask >>= 1

-				for drive in drives:
-					final_drive_name = drive + ':\\'
-					# print ('disc check: {}'.format(final_drive_name))
-					try:
-						volume_info = str(subprocess.check_output('cmd /C dir ' + final_drive_name, stderr=subprocess.STDOUT))
-					except Exception as e:
-						print ('error:{}'.format(e))
-						continue
-					else:
-						if target_drive in volume_info and not target_file_found:  # set upload if not found target file yet
-							target_drive_found = True
-							upload_disk = final_drive_name
-						if target_filename in volume_info:
-							if not target_file_found:
-								upload_disk = final_drive_name
-							target_file_found = True
+                for drive in drives:
+                    final_drive_name = drive + ':'
+                    # print ('disc check: {}'.format(final_drive_name))
+                    try:
+                        volume_info = str(subprocess.check_output('cmd /C dir ' + final_drive_name, stderr=subprocess.STDOUT))
+                    except Exception as e:
+                        print ('error:{}'.format(e))
+                        continue
+                    else:
+                        if target_drive in volume_info and not target_file_found:  # set upload if not found target file yet
+                            target_drive_found = True
+                            upload_disk = PureWindowsPath(final_drive_name)
+                        if target_filename in volume_info:
+                            if not target_file_found:
+                                upload_disk = PureWindowsPath(final_drive_name)
+                            target_file_found = True

-			elif current_OS == 'Linux':
-				#
-				# platformio.ini will accept this for a Linux upload port designation: 'upload_port = /media/media_name/drive'
-				#
-				drives = os.listdir(os.path.join(os.sep, 'media', getpass.getuser()))
-				if target_drive in drives:  # If target drive is found, use it.
-					target_drive_found = True
-					upload_disk = os.path.join(os.sep, 'media', getpass.getuser(), target_drive) + os.sep
-				else:
-					for drive in drives:
-						try:
-							files = os.listdir(os.path.join(os.sep, 'media', getpass.getuser(), drive))
-						except:
-							continue
-						else:
-							if target_filename in files:
-								upload_disk = os.path.join(os.sep, 'media', getpass.getuser(), drive) + os.sep
-								target_file_found = True
-								break
-				#
-				# set upload_port to drive if found
-				#
+            elif current_OS == 'Linux':
+                #
+                # platformio.ini will accept this for a Linux upload port designation: 'upload_port = /media/media_name/drive'
+                #
+                import getpass
+                user = getpass.getuser()
+                mpath = Path('/media', user)
+                drives = [ x for x in mpath.iterdir() if x.is_dir() ]
+                if target_drive in drives:  # If target drive is found, use it.
+                    target_drive_found = True
+                    upload_disk = mpath / target_drive
+                else:
+                    for drive in drives:
+                        try:
+                            fpath = mpath / drive
+                            filenames = [ x.name for x in fpath.iterdir() if x.is_file() ]
+                        except:
+                            continue
+                        else:
+                            if target_filename in filenames:
+                                upload_disk = mpath / drive
+                                target_file_found = True
+                                break
+                #
+                # set upload_port to drive if found
+                #

-				if target_file_found or target_drive_found:
-					env.Replace(
-						UPLOAD_FLAGS="-P$UPLOAD_PORT"
-					)
+                if target_file_found or target_drive_found:
+                    env.Replace(
+                        UPLOAD_FLAGS="-P$UPLOAD_PORT"
+                    )

-			elif current_OS == 'Darwin':  # MAC
-				#
-				# platformio.ini will accept this for a OSX upload port designation: 'upload_port = /media/media_name/drive'
-				#
-				drives = os.listdir('/Volumes')  # human readable names
-				if target_drive in drives and not target_file_found:  # set upload if not found target file yet
-					target_drive_found = True
-					upload_disk = '/Volumes/' + target_drive + '/'
-				for drive in drives:
-					try:
-						filenames = os.listdir('/Volumes/' + drive + '/')   # will get an error if the drive is protected
-					except:
-						continue
-					else:
-						if target_filename in filenames:
-							if not target_file_found:
-								upload_disk = '/Volumes/' + drive + '/'
-							target_file_found = True
+            elif current_OS == 'Darwin':  # MAC
+                #
+                # platformio.ini will accept this for a OSX upload port designation: 'upload_port = /media/media_name/drive'
+                #
+                dpath = Path('/Volumes')  # human readable names
+                drives = [ x for x in dpath.iterdir() if x.is_dir() ]
+                if target_drive in drives and not target_file_found:  # set upload if not found target file yet
+                    target_drive_found = True
+                    upload_disk = dpath / target_drive
+                for drive in drives:
+                    try:
+                        fpath = dpath / drive   # will get an error if the drive is protected
+                        filenames = [ x.name for x in fpath.iterdir() if x.is_file() ]
+                    except:
+                        continue
+                    else:
+                        if target_filename in filenames:
+                            upload_disk = dpath / drive
+                            target_file_found = True
+                            break

-			#
-			# Set upload_port to drive if found
-			#
-			if target_file_found or target_drive_found:
-				env.Replace(UPLOAD_PORT=upload_disk)
-				print('\nUpload disk: ', upload_disk, '\n')
-			else:
-				print_error('Autodetect Error')
+            #
+            # Set upload_port to drive if found
+            #
+            if target_file_found or target_drive_found:
+                env.Replace(UPLOAD_PORT=str(upload_disk))
+                print('\nUpload disk: ', upload_disk, '\n')
+            else:
+                print_error('Autodetect Error')

-		except Exception as e:
-			print_error(str(e))
+        except Exception as e:
+            print_error(str(e))

-	env.AddPreAction("upload", before_upload)
+    env.AddPreAction("upload", before_upload)
@@ -1,72 +0,0 @@
-/**
- * Marlin 3D Printer Firmware
- * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- *
- * Based on Sprinter and grbl.
- * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- *
- */
-#ifdef TARGET_LPC1768
-
-#include "../../inc/MarlinConfig.h"
-
-#if ENABLED(USE_WATCHDOG)
-
-#include <lpc17xx_wdt.h>
-#include "watchdog.h"
-
-#define WDT_TIMEOUT_US TERN(WATCHDOG_DURATION_8S, 8000000, 4000000) // 4 or 8 second timeout
-
-void watchdog_init() {
-  #if ENABLED(WATCHDOG_RESET_MANUAL)
-    // We enable the watchdog timer, but only for the interrupt.
-
-    // Configure WDT to only trigger an interrupt
-    // Disable WDT interrupt (just in case, to avoid triggering it!)
-    NVIC_DisableIRQ(WDT_IRQn);
-
-    // We NEED memory barriers to ensure Interrupts are actually disabled!
-    // ( https://dzone.com/articles/nvic-disabling-interrupts-on-arm-cortex-m-and-the )
-    __DSB();
-    __ISB();
-
-    // Configure WDT to only trigger an interrupt
-    // Initialize WDT with the given parameters
-    WDT_Init(WDT_CLKSRC_IRC, WDT_MODE_INT_ONLY);
-
-    // Configure and enable WDT interrupt.
-    NVIC_ClearPendingIRQ(WDT_IRQn);
-    NVIC_SetPriority(WDT_IRQn, 0); // Use highest priority, so we detect all kinds of lockups
-    NVIC_EnableIRQ(WDT_IRQn);
-  #else
-    WDT_Init(WDT_CLKSRC_IRC, WDT_MODE_RESET);
-  #endif
-  WDT_Start(WDT_TIMEOUT_US);
-}
-
-void HAL_watchdog_refresh() {
-  WDT_Feed();
-  #if DISABLED(PINS_DEBUGGING) && PIN_EXISTS(LED)
-    TOGGLE(LED_PIN);  // heartbeat indicator
-  #endif
-}
-
-// Timeout state
-bool watchdog_timed_out() { return TEST(WDT_ReadTimeOutFlag(), 0); }
-void watchdog_clear_timeout_flag() { WDT_ClrTimeOutFlag(); }
-
-#endif // USE_WATCHDOG
-#endif // TARGET_LPC1768
@@ -21,18 +21,10 @@
 */
 #pragma once

-#define CPU_32_BIT
-#define HAL_IDLETASK
-void HAL_idletask();
-
-#define F_CPU 100000000
-#define SystemCoreClock F_CPU
 #include <stdint.h>
 #include <stdarg.h>
-
 #undef min
 #undef max
-
 #include <algorithm>
 #include "pinmapping.h"

@@ -40,8 +32,6 @@ void _printf (const  char *format, ...);
 void _putc(uint8_t c);
 uint8_t _getc();

-//extern "C" volatile uint32_t _millis;
-
 //arduino: Print.h
 #define DEC 10
 #define HEX 16
@@ -55,10 +45,25 @@ uint8_t _getc();
 #include "../shared/math_32bit.h"
 #include "../shared/HAL_SPI.h"
 #include "fastio.h"
-#include "watchdog.h"
 #include "serial.h"

-#define SHARED_SERVOS HAS_SERVOS
+// ------------------------
+// Defines
+// ------------------------
+
+#define CPU_32_BIT
+#define SHARED_SERVOS HAS_SERVOS  // Use shared/servos.cpp
+
+#define F_CPU 100000000
+#define SystemCoreClock F_CPU
+
+#define CPU_ST7920_DELAY_1 600
+#define CPU_ST7920_DELAY_2 750
+#define CPU_ST7920_DELAY_3 750
+
+// ------------------------
+// Serial ports
+// ------------------------

 extern MSerialT serial_stream_0;
 extern MSerialT serial_stream_1;
@@ -98,49 +103,19 @@ extern MSerialT serial_stream_3;
  #endif
 #endif

-
-#define CPU_ST7920_DELAY_1 600
-#define CPU_ST7920_DELAY_2 750
-#define CPU_ST7920_DELAY_3 750
-
-//
+// ------------------------
 // Interrupts
-//
+// ------------------------
+
 #define CRITICAL_SECTION_START()
 #define CRITICAL_SECTION_END()
-#define ISRS_ENABLED()
-#define ENABLE_ISRS()
-#define DISABLE_ISRS()
-
-inline void HAL_init() {}
-
-// Utility functions
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-function"
-int freeMemory();
-#pragma GCC diagnostic pop

+// ------------------------
 // ADC
+// ------------------------
+
 #define HAL_ADC_VREF           5.0
 #define HAL_ADC_RESOLUTION    10
-#define HAL_ANALOG_SELECT(ch) HAL_adc_enable_channel(ch)
-#define HAL_START_ADC(ch)     HAL_adc_start_conversion(ch)
-#define HAL_READ_ADC()        HAL_adc_get_result()
-#define HAL_ADC_READY()       true
-
-void HAL_adc_init();
-void HAL_adc_enable_channel(const uint8_t ch);
-void HAL_adc_start_conversion(const uint8_t ch);
-uint16_t HAL_adc_get_result();
-
-// PWM
-inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
-
-// Reset source
-inline void HAL_clear_reset_source(void) {}
-inline uint8_t HAL_get_reset_source(void) { return RST_POWER_ON; }
-
-void HAL_reboot();

 /* ---------------- Delay in cycles */

@@ -159,29 +134,22 @@ constexpr inline std::size_t strlen_constexpr(const char* str) {
  // https://github.com/gcc-mirror/gcc/blob/5c7634a0e5f202935aa6c11b6ea953b8bf80a00a/libstdc%2B%2B-v3/include/bits/char_traits.h#L329
  if (str != nullptr) {
    std::size_t i = 0;
-    while (str[i] != '\0') {
-      ++i;
-    }
-
+    while (str[i] != '\0') ++i;
    return i;
  }
-
  return 0;
 }

 constexpr inline int strncmp_constexpr(const char* lhs, const char* rhs, std::size_t count) {
  // https://github.com/gcc-mirror/gcc/blob/13b9cbfc32fe3ac4c81c4dd9c42d141c8fb95db4/libstdc%2B%2B-v3/include/bits/char_traits.h#L655
-  if (lhs == nullptr || rhs == nullptr) {
+  if (lhs == nullptr || rhs == nullptr)
    return rhs != nullptr ? -1 : 1;
-  }

-  for (std::size_t i = 0; i < count; ++i) {
-    if (lhs[i] != rhs[i]) {
+  for (std::size_t i = 0; i < count; ++i)
+    if (lhs[i] != rhs[i])
      return lhs[i] < rhs[i] ? -1 : 1;
-    } else if (lhs[i] == '\0') {
+    else if (lhs[i] == '\0')
      return 0;
-    }
-  }

  return 0;
 }
@@ -193,14 +161,11 @@ constexpr inline const char* strstr_constexpr(const char* str, const char* targe
    do {
      char sc = {};
      do {
-        if ((sc = *str++) == '\0') {
-          return nullptr;
-        }
+        if ((sc = *str++) == '\0') return nullptr;
      } while (sc != c);
    } while (strncmp_constexpr(str, target, len) != 0);
    --str;
  }
-
  return str;
 }

@@ -211,12 +176,91 @@ constexpr inline char* strstr_constexpr(char* str, const char* target) {
    do {
      char sc = {};
      do {
-        if ((sc = *str++) == '\0') {
-          return nullptr;
-        }
+        if ((sc = *str++) == '\0') return nullptr;
      } while (sc != c);
    } while (strncmp_constexpr(str, target, len) != 0);
    --str;
  }
  return str;
 }
+
+// ------------------------
+// Free Memory Accessor
+// ------------------------
+
+#pragma GCC diagnostic push
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+int freeMemory();
+
+#pragma GCC diagnostic pop
+
+// ------------------------
+// MarlinHAL Class
+// ------------------------
+
+class MarlinHAL {
+public:
+
+  // Earliest possible init, before setup()
+  MarlinHAL() {}
+
+  // Watchdog
+  static void watchdog_init()    IF_DISABLED(USE_WATCHDOG, {});
+  static void watchdog_refresh() IF_DISABLED(USE_WATCHDOG, {});
+
+  static void init() {}        // Called early in setup()
+  static void init_board() {}  // Called less early in setup()
+  static void reboot();        // Restart the firmware from 0x0
+
+  // Interrupts
+  static bool isr_state() { return true; }
+  static void isr_on()  {}
+  static void isr_off() {}
+
+  static void delay_ms(const int ms) { _delay_ms(ms); }
+
+  // Tasks, called from idle()
+  static void idletask();
+
+  // Reset
+  static constexpr uint8_t reset_reason = RST_POWER_ON;
+  static uint8_t get_reset_source() { return reset_reason; }
+  static void clear_reset_source() {}
+
+  // Free SRAM
+  static int freeMemory() { return ::freeMemory(); }
+
+  //
+  // ADC Methods
+  //
+
+  static uint8_t active_ch;
+
+  // Called by Temperature::init once at startup
+  static void adc_init();
+
+  // Called by Temperature::init for each sensor at startup
+  static void adc_enable(const uint8_t ch);
+
+  // Begin ADC sampling on the given channel. Called from Temperature::isr!
+  static void adc_start(const uint8_t ch);
+
+  // Is the ADC ready for reading?
+  static bool adc_ready();
+
+  // The current value of the ADC register
+  static uint16_t adc_value();
+
+  /**
+   * Set the PWM duty cycle for the pin to the given value.
+   * No option to invert the duty cycle [default = false]
+   * No option to change the scale of the provided value to enable finer PWM duty control [default = 255]
+   */
+  static void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) {
+    analogWrite(pin, v);
+  }
+
+};
@@ -44,7 +44,7 @@
 *
 * Now you can simply SET_OUTPUT(STEP); WRITE(STEP, HIGH); WRITE(STEP, LOW);
 *
- * Why double up on these macros? see http://gcc.gnu.org/onlinedocs/cpp/Stringification.html
+ * Why double up on these macros? see https://gcc.gnu.org/onlinedocs/cpp/Stringification.html
 */

 /// Read a pin
@@ -51,7 +51,7 @@ enum XPTCoordinate : uint8_t {
  XPT2046_Z2 = 0x40 | XPT2046_CONTROL | XPT2046_DFR_MODE,
 };

-#if !defined(XPT2046_Z1_THRESHOLD)
+#ifndef XPT2046_Z1_THRESHOLD
  #define XPT2046_Z1_THRESHOLD 10
 #endif

@@ -87,5 +87,5 @@ void HAL_timer_enable_interrupt(const uint8_t timer_num);
 void HAL_timer_disable_interrupt(const uint8_t timer_num);
 bool HAL_timer_interrupt_enabled(const uint8_t timer_num);

-#define HAL_timer_isr_prologue(T)
-#define HAL_timer_isr_epilogue(T)
+#define HAL_timer_isr_prologue(T) NOOP
+#define HAL_timer_isr_epilogue(T) NOOP
@@ -38,13 +38,13 @@
 #ifdef __cplusplus
  extern "C" {
 #endif
-void u8g_SetPinOutput(uint8_t internal_pin_number){SET_DIR_OUTPUT(internal_pin_number);}
-void u8g_SetPinInput(uint8_t internal_pin_number){SET_DIR_INPUT(internal_pin_number);}
-void u8g_SetPinLevel(uint8_t  pin, uint8_t  pin_status){WRITE_PIN(pin, pin_status);}
-uint8_t u8g_GetPinLevel(uint8_t pin){return READ_PIN(pin);}
-void usleep(uint64_t microsec){
-assert(false); // why we here?
-}
+
+void u8g_SetPinOutput(uint8_t internal_pin_number) { SET_DIR_OUTPUT(internal_pin_number); }
+void u8g_SetPinInput(uint8_t internal_pin_number) { SET_DIR_INPUT(internal_pin_number); }
+void u8g_SetPinLevel(uint8_t pin, uint8_t pin_status) { WRITE_PIN(pin, pin_status); }
+uint8_t u8g_GetPinLevel(uint8_t pin) { return READ_PIN(pin); }
+void usleep(uint64_t microsec) { assert(false); /* why we here? */ }
+
 #ifdef __cplusplus
  }
 #endif
@@ -42,10 +42,6 @@
  #endif
 #endif

-// ------------------------
-// Local defines
-// ------------------------
-
 #define GET_TEMP_0_ADC()          TERN(HAS_TEMP_ADC_0,        PIN_TO_ADC(TEMP_0_PIN),       -1)
 #define GET_TEMP_1_ADC()          TERN(HAS_TEMP_ADC_1,        PIN_TO_ADC(TEMP_1_PIN),       -1)
 #define GET_TEMP_2_ADC()          TERN(HAS_TEMP_ADC_2,        PIN_TO_ADC(TEMP_2_PIN),       -1)
@@ -61,17 +57,21 @@
 #define GET_BOARD_ADC()           TERN(HAS_TEMP_ADC_BOARD,    PIN_TO_ADC(TEMP_BOARD_PIN),   -1)
 #define GET_FILAMENT_WIDTH_ADC()  TERN(FILAMENT_WIDTH_SENSOR, PIN_TO_ADC(FILWIDTH_PIN),     -1)
 #define GET_BUTTONS_ADC()         TERN(HAS_ADC_BUTTONS,       PIN_TO_ADC(ADC_KEYPAD_PIN),   -1)
+#define GET_JOY_ADC_X()           TERN(HAS_JOY_ADC_X,         PIN_TO_ADC(JOY_X_PIN),        -1)
+#define GET_JOY_ADC_Y()           TERN(HAS_JOY_ADC_Y,         PIN_TO_ADC(JOY_Y_PIN),        -1)
+#define GET_JOY_ADC_Z()           TERN(HAS_JOY_ADC_Z,         PIN_TO_ADC(JOY_Z_PIN),        -1)

 #define IS_ADC_REQUIRED(n) ( \
     GET_TEMP_0_ADC() == n || GET_TEMP_1_ADC() == n || GET_TEMP_2_ADC() == n || GET_TEMP_3_ADC() == n \
  || GET_TEMP_4_ADC() == n || GET_TEMP_5_ADC() == n || GET_TEMP_6_ADC() == n || GET_TEMP_7_ADC() == n \
-  || GET_BED_ADC() == n            \
-  || GET_CHAMBER_ADC() == n        \
-  || GET_PROBE_ADC() == n          \
-  || GET_COOLER_ADC() == n         \
-  || GET_BOARD_ADC() == n          \
+  || GET_BED_ADC() == n \
+  || GET_CHAMBER_ADC() == n \
+  || GET_PROBE_ADC() == n \
+  || GET_COOLER_ADC() == n \
+  || GET_BOARD_ADC() == n \
  || GET_FILAMENT_WIDTH_ADC() == n \
-  || GET_BUTTONS_ADC() == n        \
+  || GET_BUTTONS_ADC() == n \
+  || GET_JOY_ADC_X() == n || GET_JOY_ADC_Y() == n || GET_JOY_ADC_Z() == n \
 )

 #if IS_ADC_REQUIRED(0)
@@ -91,6 +91,152 @@
  #define DMA_IS_REQUIRED 1
 #endif

+enum ADCIndex {
+  #if GET_TEMP_0_ADC() == 0
+    TEMP_0,
+  #endif
+  #if GET_TEMP_1_ADC() == 0
+    TEMP_1,
+  #endif
+  #if GET_TEMP_2_ADC() == 0
+    TEMP_2,
+  #endif
+  #if GET_TEMP_3_ADC() == 0
+    TEMP_3,
+  #endif
+  #if GET_TEMP_4_ADC() == 0
+    TEMP_4,
+  #endif
+  #if GET_TEMP_5_ADC() == 0
+    TEMP_5,
+  #endif
+  #if GET_TEMP_6_ADC() == 0
+    TEMP_6,
+  #endif
+  #if GET_TEMP_7_ADC() == 0
+    TEMP_7,
+  #endif
+  #if GET_BED_ADC() == 0
+    TEMP_BED,
+  #endif
+  #if GET_CHAMBER_ADC() == 0
+    TEMP_CHAMBER,
+  #endif
+  #if GET_PROBE_ADC() == 0
+    TEMP_PROBE,
+  #endif
+  #if GET_COOLER_ADC() == 0
+    TEMP_COOLER,
+  #endif
+  #if GET_BOARD_ADC() == 0
+    TEMP_BOARD,
+  #endif
+  #if GET_FILAMENT_WIDTH_ADC() == 0
+    FILWIDTH,
+  #endif
+  #if GET_BUTTONS_ADC() == 0
+    ADC_KEY,
+  #endif
+  #if GET_JOY_ADC_X() == 0
+    JOY_X,
+  #endif
+  #if GET_JOY_ADC_Y() == 0
+    JOY_Y,
+  #endif
+  #if GET_JOY_ADC_Z() == 0
+    JOY_Z,
+  #endif
+  #if GET_TEMP_0_ADC() == 1
+    TEMP_0,
+  #endif
+  #if GET_TEMP_1_ADC() == 1
+    TEMP_1,
+  #endif
+  #if GET_TEMP_2_ADC() == 1
+    TEMP_2,
+  #endif
+  #if GET_TEMP_3_ADC() == 1
+    TEMP_3,
+  #endif
+  #if GET_TEMP_4_ADC() == 1
+    TEMP_4,
+  #endif
+  #if GET_TEMP_5_ADC() == 1
+    TEMP_5,
+  #endif
+  #if GET_TEMP_6_ADC() == 1
+    TEMP_6,
+  #endif
+  #if GET_TEMP_7_ADC() == 1
+    TEMP_7,
+  #endif
+  #if GET_BED_ADC() == 1
+    TEMP_BED,
+  #endif
+  #if GET_CHAMBER_ADC() == 1
+    TEMP_CHAMBER,
+  #endif
+  #if GET_PROBE_ADC() == 1
+    TEMP_PROBE,
+  #endif
+  #if GET_COOLER_ADC() == 1
+    TEMP_COOLER,
+  #endif
+  #if GET_BOARD_ADC() == 1
+    TEMP_BOARD,
+  #endif
+  #if GET_FILAMENT_WIDTH_ADC() == 1
+    FILWIDTH,
+  #endif
+  #if GET_BUTTONS_ADC() == 1
+    ADC_KEY,
+  #endif
+  #if GET_JOY_ADC_X() == 1
+    JOY_X,
+  #endif
+  #if GET_JOY_ADC_Y() == 1
+    JOY_Y,
+  #endif
+  #if GET_JOY_ADC_Z() == 1
+    JOY_Z,
+  #endif
+  ADC_COUNT
+};
+
+#if ENABLED(USE_WATCHDOG)
+
+  #define WDT_TIMEOUT_REG TERN(WATCHDOG_DURATION_8S, WDT_CONFIG_PER_CYC8192, WDT_CONFIG_PER_CYC4096) // 4 or 8 second timeout
+
+  void MarlinHAL::watchdog_init() {
+    // The low-power oscillator used by the WDT runs at 32,768 Hz with
+    // a 1:32 prescale, thus 1024 Hz, though probably not super precise.
+
+    // Setup WDT clocks
+    MCLK->APBAMASK.bit.OSC32KCTRL_ = true;
+    MCLK->APBAMASK.bit.WDT_ = true;
+    OSC32KCTRL->OSCULP32K.bit.EN1K = true;  // Enable out 1K (this is what WDT uses)
+
+    WDT->CTRLA.bit.ENABLE = false;          // Disable watchdog for config
+    SYNC(WDT->SYNCBUSY.bit.ENABLE);
+
+    WDT->INTENCLR.reg = WDT_INTENCLR_EW;    // Disable early warning interrupt
+    WDT->CONFIG.reg = WDT_TIMEOUT_REG;      // Set a 4s or 8s period for chip reset
+
+    hal.watchdog_refresh();
+
+    WDT->CTRLA.reg = WDT_CTRLA_ENABLE;      // Start watchdog now in normal mode
+    SYNC(WDT->SYNCBUSY.bit.ENABLE);
+  }
+
+  // Reset watchdog. MUST be called at least every 4 seconds after the
+  // first watchdog_init or SAMD will go into emergency procedures.
+  void MarlinHAL::watchdog_refresh() {
+    SYNC(WDT->SYNCBUSY.bit.CLEAR);        // Test first if previous is 'ongoing' to save time waiting for command execution
+    WDT->CLEAR.reg = WDT_CLEAR_CLEAR_KEY;
+  }
+
+#endif
+
 // ------------------------
 // Types
 // ------------------------
@@ -108,12 +254,10 @@
 // Private Variables
 // ------------------------

-uint16_t HAL_adc_result;
-
 #if ADC_IS_REQUIRED

  // Pins used by ADC inputs. Order must be ADC0 inputs first then ADC1
-  const uint8_t adc_pins[] = {
+  static constexpr uint8_t adc_pins[ADC_COUNT] = {
    // ADC0 pins
    #if GET_TEMP_0_ADC() == 0
      TEMP_0_PIN,
@@ -160,6 +304,15 @@ uint16_t HAL_adc_result;
    #if GET_BUTTONS_ADC() == 0
      ADC_KEYPAD_PIN,
    #endif
+    #if GET_JOY_ADC_X() == 0
+      JOY_X_PIN,
+    #endif
+    #if GET_JOY_ADC_Y() == 0
+      JOY_Y_PIN,
+    #endif
+    #if GET_JOY_ADC_Z() == 0
+      JOY_Z_PIN,
+    #endif
    // ADC1 pins
    #if GET_TEMP_0_ADC() == 1
      TEMP_0_PIN,
@@ -206,15 +359,23 @@ uint16_t HAL_adc_result;
    #if GET_BUTTONS_ADC() == 1
      ADC_KEYPAD_PIN,
    #endif
+    #if GET_JOY_ADC_X() == 1
+      JOY_X_PIN,
+    #endif
+    #if GET_JOY_ADC_Y() == 1
+      JOY_Y_PIN,
+    #endif
+    #if GET_JOY_ADC_Z() == 1
+      JOY_Z_PIN,
+    #endif
  };

-  uint16_t HAL_adc_results[COUNT(adc_pins)];
+  static uint16_t adc_results[ADC_COUNT];

  #if ADC0_IS_REQUIRED
-    Adafruit_ZeroDMA adc0DMAProgram,
-                     adc0DMARead;
+    Adafruit_ZeroDMA adc0DMAProgram, adc0DMARead;

-    const HAL_DMA_DAC_Registers adc0_dma_regs_list[] = {
+    static constexpr HAL_DMA_DAC_Registers adc0_dma_regs_list[ADC_COUNT] = {
      #if GET_TEMP_0_ADC() == 0
        { PIN_TO_INPUTCTRL(TEMP_0_PIN) },
      #endif
@@ -260,16 +421,24 @@ uint16_t HAL_adc_result;
      #if GET_BUTTONS_ADC() == 0
        { PIN_TO_INPUTCTRL(ADC_KEYPAD_PIN) },
      #endif
+      #if GET_JOY_ADC_X() == 0
+        { PIN_TO_INPUTCTRL(JOY_X_PIN) },
+      #endif
+      #if GET_JOY_ADC_Y() == 0
+        { PIN_TO_INPUTCTRL(JOY_Y_PIN) },
+      #endif
+      #if GET_JOY_ADC_Z() == 0
+        { PIN_TO_INPUTCTRL(JOY_Z_PIN) },
+      #endif
    };

    #define ADC0_AINCOUNT   COUNT(adc0_dma_regs_list)
  #endif // ADC0_IS_REQUIRED

  #if ADC1_IS_REQUIRED
-    Adafruit_ZeroDMA adc1DMAProgram,
-                     adc1DMARead;
+    Adafruit_ZeroDMA adc1DMAProgram, adc1DMARead;

-    const HAL_DMA_DAC_Registers adc1_dma_regs_list[] = {
+    static constexpr HAL_DMA_DAC_Registers adc1_dma_regs_list[ADC_COUNT] = {
      #if GET_TEMP_0_ADC() == 1
        { PIN_TO_INPUTCTRL(TEMP_0_PIN) },
      #endif
@@ -315,6 +484,15 @@ uint16_t HAL_adc_result;
      #if GET_BUTTONS_ADC() == 1
        { PIN_TO_INPUTCTRL(ADC_KEYPAD_PIN) },
      #endif
+      #if GET_JOY_ADC_X() == 1
+        { PIN_TO_INPUTCTRL(JOY_X_PIN) },
+      #endif
+      #if GET_JOY_ADC_Y() == 1
+        { PIN_TO_INPUTCTRL(JOY_Y_PIN) },
+      #endif
+      #if GET_JOY_ADC_Z() == 1
+        { PIN_TO_INPUTCTRL(JOY_Z_PIN) },
+      #endif
    };

    #define ADC1_AINCOUNT   COUNT(adc1_dma_regs_list)
@@ -326,9 +504,10 @@ uint16_t HAL_adc_result;
 // Private functions
 // ------------------------

-#if DMA_IS_REQUIRED
+void MarlinHAL::dma_init() {
+
+  #if DMA_IS_REQUIRED

-  void dma_init() {
    DmacDescriptor *descriptor;

    #if ADC0_IS_REQUIRED
@@ -357,7 +536,7 @@ uint16_t HAL_adc_result;
      if (adc0DMARead.allocate() == DMA_STATUS_OK) {
        adc0DMARead.addDescriptor(
          (void *)&ADC0->RESULT.reg,          // SRC
-          &HAL_adc_results,                   // DEST
+          &adc_results,                       // DEST
          ADC0_AINCOUNT,                      // CNT
          DMA_BEAT_SIZE_HWORD,
          false,                              // SRCINC
@@ -394,7 +573,7 @@ uint16_t HAL_adc_result;
      if (adc1DMARead.allocate() == DMA_STATUS_OK) {
        adc1DMARead.addDescriptor(
          (void *)&ADC1->RESULT.reg,          // SRC
-          &HAL_adc_results[ADC0_AINCOUNT],    // DEST
+          &adc_results[ADC0_AINCOUNT],        // DEST
          ADC1_AINCOUNT,                      // CNT
          DMA_BEAT_SIZE_HWORD,
          false,                              // SRCINC
@@ -407,36 +586,28 @@ uint16_t HAL_adc_result;
    #endif

    DMAC->PRICTRL0.bit.RRLVLEN0 = true;                         // Activate round robin for DMA channels required by ADCs
-  }

-#endif // DMA_IS_REQUIRED
+  #endif // DMA_IS_REQUIRED
+}

 // ------------------------
 // Public functions
 // ------------------------

 // HAL initialization task
-void HAL_init() {
+void MarlinHAL::init() {
  TERN_(DMA_IS_REQUIRED, dma_init());
  #if ENABLED(SDSUPPORT)
-    #if SD_CONNECTION_IS(ONBOARD) && PIN_EXISTS(SD_DETECT)
+    #if HAS_SD_DETECT && SD_CONNECTION_IS(ONBOARD)
      SET_INPUT_PULLUP(SD_DETECT_PIN);
    #endif
    OUT_WRITE(SDSS, HIGH);  // Try to set SDSS inactive before any other SPI users start up
  #endif
 }

-// HAL idle task
-/*
-void HAL_idletask() {
-}
-*/
-
-void HAL_clear_reset_source() { }
-
 #pragma push_macro("WDT")
 #undef WDT    // Required to be able to use '.bit.WDT'. Compiler wrongly replace struct field with WDT define
-uint8_t HAL_get_reset_source() {
+uint8_t MarlinHAL::get_reset_source() {
  RSTC_RCAUSE_Type resetCause;

  resetCause.reg = REG_RSTC_RCAUSE;
@@ -450,7 +621,7 @@ uint8_t HAL_get_reset_source() {
 }
 #pragma pop_macro("WDT")

-void HAL_reboot() { NVIC_SystemReset(); }
+void MarlinHAL::reboot() { NVIC_SystemReset(); }

 extern "C" {
  void * _sbrk(int incr);
@@ -468,9 +639,11 @@ int freeMemory() {
 // ADC
 // ------------------------

-void HAL_adc_init() {
+uint16_t MarlinHAL::adc_result;
+
+void MarlinHAL::adc_init() {
  #if ADC_IS_REQUIRED
-    memset(HAL_adc_results, 0xFF, sizeof(HAL_adc_results));                 // Fill result with invalid values
+    memset(adc_results, 0xFF, sizeof(adc_results));                         // Fill result with invalid values

    LOOP_L_N(pi, COUNT(adc_pins))
      pinPeripheral(adc_pins[pi], PIO_ANALOG);
@@ -505,17 +678,13 @@ void HAL_adc_init() {
  #endif // ADC_IS_REQUIRED
 }

-void HAL_adc_start_conversion(const uint8_t adc_pin) {
+void MarlinHAL::adc_start(const pin_t pin) {
  #if ADC_IS_REQUIRED
-    LOOP_L_N(pi, COUNT(adc_pins)) {
-      if (adc_pin == adc_pins[pi]) {
-        HAL_adc_result = HAL_adc_results[pi];
-        return;
-      }
-    }
+    LOOP_L_N(pi, COUNT(adc_pins))
+      if (pin == adc_pins[pi]) { adc_result = adc_results[pi]; return; }
  #endif

-  HAL_adc_result = 0xFFFF;
+  adc_result = 0xFFFF;
 }

 #endif // __SAMD51__
@@ -26,7 +26,6 @@
 #include "../shared/math_32bit.h"
 #include "../shared/HAL_SPI.h"
 #include "fastio.h"
-#include "watchdog.h"

 #ifdef ADAFRUIT_GRAND_CENTRAL_M4
  #include "MarlinSerial_AGCM4.h"
@@ -89,51 +88,30 @@

 typedef int8_t pin_t;

-#define SHARED_SERVOS HAS_SERVOS
-#define HAL_SERVO_LIB Servo
+#define SHARED_SERVOS HAS_SERVOS  // Use shared/servos.cpp
+
+class Servo;
+typedef Servo hal_servo_t;

 //
 // Interrupts
 //
-#define CRITICAL_SECTION_START()  uint32_t primask = __get_PRIMASK(); __disable_irq()
-#define CRITICAL_SECTION_END()    if (!primask) __enable_irq()
-#define ISRS_ENABLED() (!__get_PRIMASK())
-#define ENABLE_ISRS()  __enable_irq()
-#define DISABLE_ISRS() __disable_irq()
+#define CRITICAL_SECTION_START()  const bool irqon = !__get_PRIMASK(); __disable_irq()
+#define CRITICAL_SECTION_END()    if (irqon) __enable_irq()

-#define cli() __disable_irq()       // Disable interrupts
-#define sei() __enable_irq()        // Enable interrupts
-
-void HAL_clear_reset_source();  // clear reset reason
-uint8_t HAL_get_reset_source(); // get reset reason
-
-void HAL_reboot();
+#define cli() __disable_irq() // Disable interrupts
+#define sei() __enable_irq()  // Enable interrupts

 //
 // ADC
 //
-extern uint16_t HAL_adc_result;     // Most recent ADC conversion
-
-#define HAL_ANALOG_SELECT(pin)
-
-void HAL_adc_init();

 //#define HAL_ADC_FILTERED          // Disable Marlin's oversampling. The HAL filters ADC values.
 #define HAL_ADC_VREF         3.3
 #define HAL_ADC_RESOLUTION  10      // ... 12
-#define HAL_START_ADC(pin)  HAL_adc_start_conversion(pin)
-#define HAL_READ_ADC()      HAL_adc_result
-#define HAL_ADC_READY()     true
-
-void HAL_adc_start_conversion(const uint8_t adc_pin);

 //
-// PWM
-//
-inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) { analogWrite(pin, v); }
-
-//
-// Pin Map
+// Pin Mapping for M42, M43, M226
 //
 #define GET_PIN_MAP_PIN(index) index
 #define GET_PIN_MAP_INDEX(pin) pin
@@ -142,35 +120,97 @@ inline void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255,
 //
 // Tone
 //
-void toneInit();
 void tone(const pin_t _pin, const unsigned int frequency, const unsigned long duration=0);
 void noTone(const pin_t _pin);

-// Enable hooks into idle and setup for HAL
-void HAL_init();
-/*
-#define HAL_IDLETASK 1
-void HAL_idletask();
-*/
-
-//
-// Utility functions
-//
-FORCE_INLINE void _delay_ms(const int delay_ms) { delay(delay_ms); }
+// ------------------------
+// Class Utilities
+// ------------------------

 #pragma GCC diagnostic push
 #if GCC_VERSION <= 50000
  #pragma GCC diagnostic ignored "-Wunused-function"
 #endif

-int freeMemory();
-
-#pragma GCC diagnostic pop
-
 #ifdef __cplusplus
  extern "C" {
 #endif
+
 char *dtostrf(double __val, signed char __width, unsigned char __prec, char *__s);
+
+extern "C" int freeMemory();
+
 #ifdef __cplusplus
  }
 #endif
+
+#pragma GCC diagnostic pop
+
+// ------------------------
+// MarlinHAL Class
+// ------------------------
+
+class MarlinHAL {
+public:
+
+  // Earliest possible init, before setup()
+  MarlinHAL() {}
+
+  // Watchdog
+  static void watchdog_init()    IF_DISABLED(USE_WATCHDOG, {});
+  static void watchdog_refresh() IF_DISABLED(USE_WATCHDOG, {});
+
+  static void init();          // Called early in setup()
+  static void init_board() {}  // Called less early in setup()
+  static void reboot();        // Restart the firmware from 0x0
+
+  // Interrupts
+  static bool isr_state() { return !__get_PRIMASK(); }
+  static void isr_on()  { sei(); }
+  static void isr_off() { cli(); }
+
+  static void delay_ms(const int ms) { delay(ms); }
+
+  // Tasks, called from idle()
+  static void idletask() {}
+
+  // Reset
+  static uint8_t get_reset_source();
+  static void clear_reset_source() {}
+
+  // Free SRAM
+  static int freeMemory() { return ::freeMemory(); }
+
+  //
+  // ADC Methods
+  //
+
+  static uint16_t adc_result;
+
+  // Called by Temperature::init once at startup
+  static void adc_init();
+
+  // Called by Temperature::init for each sensor at startup
+  static void adc_enable(const uint8_t ch) {}
+
+  // Begin ADC sampling on the given pin. Called from Temperature::isr!
+  static void adc_start(const pin_t pin);
+
+  // Is the ADC ready for reading?
+  static bool adc_ready() { return true; }
+
+  // The current value of the ADC register
+  static uint16_t adc_value() { return adc_result; }
+
+  /**
+   * Set the PWM duty cycle for the pin to the given value.
+   * No option to invert the duty cycle [default = false]
+   * No option to change the scale of the provided value to enable finer PWM duty control [default = 255]
+   */
+  static void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) {
+    analogWrite(pin, v);
+  }
+
+private:
+  static void dma_init();
+};
@@ -77,7 +77,8 @@ HAL_SERVO_TIMER_ISR() {
  ;
  const uint8_t tcChannel = TIMER_TCCHANNEL(timer);

-  if (currentServoIndex[timer] < 0) {
+  int8_t cho = currentServoIndex[timer];                // Handle the prior servo first
+  if (cho < 0) {                                        // Servo -1 indicates the refresh interval completed...
    #if defined(_useTimer1) && defined(_useTimer2)
      if (currentServoIndex[timer ^ 1] >= 0) {
        // Wait for both channels
@@ -86,45 +87,37 @@ HAL_SERVO_TIMER_ISR() {
        return;
      }
    #endif
-    tc->COUNT16.COUNT.reg = TC_COUNTER_START_VAL;
+    tc->COUNT16.COUNT.reg = TC_COUNTER_START_VAL;       // ...so reset the timer
    SYNC(tc->COUNT16.SYNCBUSY.bit.COUNT);
  }
-  else if (SERVO_INDEX(timer, currentServoIndex[timer]) < ServoCount && SERVO(timer, currentServoIndex[timer]).Pin.isActive)
-    digitalWrite(SERVO(timer, currentServoIndex[timer]).Pin.nbr, LOW);      // pulse this channel low if activated
+  else if (SERVO_INDEX(timer, cho) < ServoCount)        // prior channel handled?
+    digitalWrite(SERVO(timer, cho).Pin.nbr, LOW);       // pulse the prior channel LOW

-  // Select the next servo controlled by this timer
-  currentServoIndex[timer]++;
+  currentServoIndex[timer] = ++cho;                     // go to the next channel (or 0)
+  if (cho < SERVOS_PER_TIMER && SERVO_INDEX(timer, cho) < ServoCount) {
+    if (SERVO(timer, cho).Pin.isActive)                 // activated?
+      digitalWrite(SERVO(timer, cho).Pin.nbr, HIGH);    // yes: pulse HIGH

-  if (SERVO_INDEX(timer, currentServoIndex[timer]) < ServoCount && currentServoIndex[timer] < SERVOS_PER_TIMER) {
-    if (SERVO(timer, currentServoIndex[timer]).Pin.isActive)                // check if activated
-      digitalWrite(SERVO(timer, currentServoIndex[timer]).Pin.nbr, HIGH);   // it's an active channel so pulse it high
-
-    tc->COUNT16.CC[tcChannel].reg = getTimerCount() - (uint16_t)SERVO(timer, currentServoIndex[timer]).ticks;
+    tc->COUNT16.CC[tcChannel].reg = getTimerCount() - (uint16_t)SERVO(timer, cho).ticks;
  }
  else {
    // finished all channels so wait for the refresh period to expire before starting over
-    currentServoIndex[timer] = -1;   // this will get incremented at the end of the refresh period to start again at the first channel
-
-    const uint16_t tcCounterValue = getTimerCount();
-
-    if ((TC_COUNTER_START_VAL - tcCounterValue) + 4UL < usToTicks(REFRESH_INTERVAL))  // allow a few ticks to ensure the next OCR1A not missed
-      tc->COUNT16.CC[tcChannel].reg = TC_COUNTER_START_VAL - (uint16_t)usToTicks(REFRESH_INTERVAL);
-    else
-      tc->COUNT16.CC[tcChannel].reg = (uint16_t)(tcCounterValue - 4UL);               // at least REFRESH_INTERVAL has elapsed
+    currentServoIndex[timer] = -1;                                          // reset the timer COUNT.reg on the next call
+    const uint16_t cval = getTimerCount() - 256 / (SERVO_TIMER_PRESCALER),  // allow 256 cycles to ensure the next CV not missed
+                   ival = (TC_COUNTER_START_VAL) - (uint16_t)usToTicks(REFRESH_INTERVAL); // at least REFRESH_INTERVAL has elapsed
+    tc->COUNT16.CC[tcChannel].reg = min(cval, ival);
  }
  if (tcChannel == 0) {
    SYNC(tc->COUNT16.SYNCBUSY.bit.CC0);
-    // Clear the interrupt
-    tc->COUNT16.INTFLAG.reg = TC_INTFLAG_MC0;
+    tc->COUNT16.INTFLAG.reg = TC_INTFLAG_MC0; // Clear the interrupt
  }
  else {
    SYNC(tc->COUNT16.SYNCBUSY.bit.CC1);
-    // Clear the interrupt
-    tc->COUNT16.INTFLAG.reg = TC_INTFLAG_MC1;
+    tc->COUNT16.INTFLAG.reg = TC_INTFLAG_MC1; // Clear the interrupt
  }
 }

-void initISR(timer16_Sequence_t timer) {
+void initISR(const timer16_Sequence_t timer) {
  Tc * const tc = timer_config[SERVO_TC].pTc;
  const uint8_t tcChannel = TIMER_TCCHANNEL(timer);

@@ -201,9 +194,9 @@ void initISR(timer16_Sequence_t timer) {
  }
 }

-void finISR(timer16_Sequence_t timer) {
+void finISR(const timer16_Sequence_t timer_index) {
  Tc * const tc = timer_config[SERVO_TC].pTc;
-  const uint8_t tcChannel = TIMER_TCCHANNEL(timer);
+  const uint8_t tcChannel = TIMER_TCCHANNEL(timer_index);

  // Disable the match channel interrupt request
  tc->COUNT16.INTENCLR.reg = (tcChannel == 0) ? TC_INTENCLR_MC0 : TC_INTENCLR_MC1;
--- a/Show More
+++ b/Show More