Add PlatformIO support (#250)

* Add package.json

To make package easily integratable with PlatformIO

* Correct name back to original one

* Format package.json

* Add first shot at builder script

* Add USB stack flags, fix compile flags

* Formatting

* Add more link & USB flags

* Build Boot2 bootloader

* Formatting

* Generate linkerscript, linker fixes

* Fix linkflags, make firmware runnable

* Update USB flags and RAM size

* Correct USB flags, add dynamic sketch partitioning

* Restructure filesystem size and flash size logic into platform code

* Move C++ only flags to CXXFLAGS

* Add PlatformIO documentation

* Link to new platform.io document in the docs TOC

* Fix typos in platformio docs

* Fix one additional typo in platformio.rst

* Update docs

* Remove wrongly commited build folder

docs/index.rst

@@ -20,6 +20,8 @@ For the latest version, always check https://github.com/earlephilhower/arduino-p
    Installation <install>
    IDE Menus <ide>
 
+   Platform.IO Integration <platformio>
+
    Pin (Re)Assignment <pins>
 
    Analog I/O <analog>

docs/platformio.rst

@@ -0,0 +1,219 @@
+Using this core with PlatformIO
+===============================
+
+What is PlatformIO? 
+-------------------
+
+`PlatformIO <https://platformio.org/>`__  is a free, open-source build-tool written in Python, which also integrates into VSCode code as an extension.
+
+PlatformIO significantly simplifies writing embedded software by offering a unified build system, yet being able to create project files for many different IDEs, including VSCode, Eclipse, CLion, etc. 
+Through this, PlatformIO can offer extensive features such as IntelliSense (autocomplete), debugging, unit testing etc., which not available in the standard Arduino IDE.
+
+The Arduino IDE experience:
+
+.. image:: images/the_arduinoide_experience.png
+
+The PlatformIO experience:
+
+.. image:: images/the_platformio_experience.png
+
+Refer to the general documentation at https://docs.platformio.org/.
+
+Especially useful is the `Getting started with VSCode + PlatformIO <https://docs.platformio.org/en/latest/integration/ide/vscode.html#installation), [CLI reference](https://docs.platformio.org/en/latest/core/index.html) and [platformio.ini options](https://docs.platformio.org/en/latest/projectconf/index.html)>`__ page.
+
+Hereafter it is assumed that you have a basic understanding of PlatformIO in regards to project creation, project file structure and building and uploading PlatformIO projects, through reading the above pages.
+
+Current state of development
+----------------------------
+
+At the time of writing, PlatformIO integration for this core is a work-in-progress and not yet merged into mainline PlatformIO. This is subject to change soon.
+
+If you want to use the PlatformIO integration right now, make sure you first create a standard Raspberry Pi Pico + Arduino project within PlatformIO. 
+This will give you a project with the ``platformio.ini`` 
+
+.. code:: ini
+
+    [env:pico]
+    platform = raspberrypi
+    board = pico
+    framework = arduino
+
+Here, you need to change the `platform` to take advantage of the features described hereunder. 
+You *also* need to inject two PlatformIO packages, one for the compiler toolchain and one for the Arduino core package.
+
+.. code:: ini
+
+    [env:pico]
+    platform = https://github.com/maxgerhardt/platform-raspberrypi.git
+    board = pico
+    framework = arduino
+    ; note that download link for toolchain is specific for OS. see https://github.com/earlephilhower/pico-quick-toolchain/releases.
+    platform_packages = 
+        maxgerhardt/framework-arduinopico@https://github.com/earlephilhower/arduino-pico.git
+        maxgerhardt/toolchain-pico@https://github.com/earlephilhower/pico-quick-toolchain/releases/download/1.3.1-a/x86_64-w64-mingw32.arm-none-eabi-7855b0c.210706.zip
+    
+When the support for this core has been merged into mainline PlatformIO, this notice will be removed and a standard `platformio.ini` as shown above will work as a base.
+
+Selecting the new core
+----------------------
+
+Prerequisite for using this core is to tell PlatformIO to switch to it.
+There will be board definition files where the Earle-Philhower core will
+be the default since it's a board that only exists in this core (and not
+the other https://github.com/arduino/ArduinoCore-mbed). To switch boards
+for which this is not the default core (e.g. the standard
+``board = pico``), the directive
+
+.. code:: ini
+
+    board_build.core = earlephilhower
+
+must be added to the ``platformio.ini``. This controls the `core
+switching
+logic <https://github.com/maxgerhardt/platform-raspberrypi/blob/77e0d3a29d1dbf00fd3ec3271104e3bf4820869c/builder/frameworks/arduino/arduino.py#L27-L32>`__.
+
+Flash size
+----------
+
+Controlled via specifying the size allocated for the filesystem.
+Available sketch size is calculated accordingly by using (as in
+``makeboards.py``) that number and the (constant) EEPROM size (4096
+bytes) and the total flash size as known to PlatformIO via the board
+definition file. The expression on the right can involve "b","k","m"
+(bytes/kilobytes/megabytes) and floating point numbers. This makes it
+actually more flexible than in the Arduino IDE where there is a finite
+list of choices. Calculations happen in `the
+platform <https://github.com/maxgerhardt/platform-raspberrypi/blob/77e0d3a29d1dbf00fd3ec3271104e3bf4820869c/builder/main.py#L118-L184>`__.
+
+.. code:: ini
+
+    ; in reference to a board = pico config (2MB flash)
+    ; Flash Size: 2MB (Sketch: 1MB, FS:1MB)
+    board_build.filesystem_size = 1m
+    ; Flash Size: 2MB (No FS)
+    board_build.filesystem_size = 0m
+    ; Flash Size: 2MB (Sketch: 0.5MB, FS:1.5MB)
+    board_build.filesystem_size = 1.5m
+
+CPU Speed
+---------
+
+As for all other PlatformIO platforms, the ``f_cpu`` macro value (which
+is passed to the core) can be changed as
+`documented <https://docs.platformio.org/en/latest/boards/raspberrypi/pico.html#configuration>`__
+
+.. code:: ini
+
+    ; 133MHz
+    board_build.f_cpu = 133000000L
+
+Debug Port
+----------
+
+Via
+`build_flags <https://docs.platformio.org/en/latest/projectconf/section_env_build.html#build-flags>`__
+as done for many other cores
+(`example <https://docs.platformio.org/en/latest/platforms/ststm32.html#configuration>`__).
+
+.. code:: ini
+
+    ; Debug Port: Serial
+    build_flags = -DDEBUG_RP2040_PORT=Serial
+    ; Debug Port: Serial 1
+    build_flags = -DDEBUG_RP2040_PORT=Serial1
+    ; Debug Port: Serial 2
+    build_flags = -DDEBUG_RP2040_PORT=Serial2
+
+Debug Level
+-----------
+
+Done again by directly adding the needed `build
+flags <https://github.com/earlephilhower/arduino-pico/blob/05356da2c5552413a442f742e209c6fa92823666/boards.txt#L104-L114>`__.
+When wanting to define multiple build flags, they must be accumulated in
+either a sing line or a newline-separated expression.
+
+.. code:: ini
+
+    ; Debug level: Core
+    build_flags = -DDEBUG_RP2040_CORE
+    ; Debug level: SPI
+    build_flags = -DDEBUG_RP2040_SPI
+    ; Debug level: Wire
+    build_flags = -DDEBUG_RP2040_WIRE
+    ; Debug level: All
+    build_flags = -DDEBUG_RP2040_WIRE -DDEBUG_RP2040_SPI -DDEBUG_RP2040_CORE
+    ; Debug level: NDEBUG
+    build_flags = -DNDEBUG
+
+    ; example: Debug port on serial 2 and all debug output
+    build_flags = -DDEBUG_RP2040_WIRE -DDEBUG_RP2040_SPI -DDEBUG_RP2040_CORE -DDEBUG_RP2040_PORT=Serial2
+    ; equivalent to above
+    build_flags = 
+       -DDEBUG_RP2040_WIRE
+       -DDEBUG_RP2040_SPI
+       -DDEBUG_RP2040_CORE
+       -DDEBUG_RP2040_PORT=Serial2
+
+USB Stack
+---------
+
+Not specifying any special build flags regarding this gives one the
+default Pico SDK USB stack. To change it, add
+
+.. code:: ini
+
+    ; Adafruit TinyUSB
+    build_flags = -DUSE_TINYUSB
+    ; No USB stack
+    build_flags = -DPIO_FRAMEWORK_ARDUINO_NO_USB
+
+Note that the special "No USB" setting is also supported, through the
+shortcut-define ``PIO_FRAMEWORK_ARDUINO_NO_USB``.
+
+
+Selecting a different core version
+----------------------------------
+
+If you wish to use a different version of the core, e.g., the latest git
+``master`` version, you can use a
+`platform_packages <https://docs.platformio.org/en/latest/projectconf/section_env_platform.html#platform-packages>`__
+directive to do so. Simply specify that the framework package
+(``framework-arduinopico``) comes from a different source.
+
+.. code:: ini
+
+    platform_packages =
+       framework-arduinopico@https://github.com/earlephilhower/arduino-pico.git#master
+
+Whereas the ``#master`` can also be replaced by a ``#branchname`` or a
+``#commithash``. If left out, it will pull the default branch, which is ``master``.
+
+The ``file://`` pseudo-protocol can also be used instead of ``https://`` to point to a
+local copy of the core (with e.g. some modifications) on disk.
+
+Note that this can only be done for versions that have the PlatformIO
+builder script it in, so versions before 1.9.2 are not supported.
+
+Examples 
+--------
+
+The following example ``platformio.ini`` can be used for a Raspberry Pi Pico
+and 0.5MByte filesystem. 
+
+.. code:: ini
+
+    [env:pico]
+    platform = https://github.com/maxgerhardt/platform-raspberrypi.git
+    board = pico
+    framework = arduino
+    build_board.core = earlephilhower
+    board_build.filesystem_size = 0.5m
+    ; note that download link for toolchain is specific for OS. see https://github.com/earlephilhower/pico-quick-toolchain/releases.
+    platform_packages = 
+        maxgerhardt/framework-arduinopico@https://github.com/earlephilhower/arduino-pico.git
+        maxgerhardt/toolchain-pico@https://github.com/earlephilhower/pico-quick-toolchain/releases/download/1.3.1-a/x86_64-w64-mingw32.arm-none-eabi-7855b0c.210706.zip
+
+
+The initial project structure should be generated just creating a new
+project for the Pico and the Arduino framework, after which the
+auto-generated ``platformio.ini`` can be adapted per above.

package.json

@@ -1,6 +1,17 @@
 {
-    "name": "framework-arduinopico",
-    "description": "Arduino Wiring-based Framework (RPi Pico RP2040)",
-    "url": "https://github.com/earlephilhower/arduino-pico",
-    "version": "0.9.2"
+  "name": "framework-arduinopico",
+  "version": "1.10903.0",
+  "description": "Arduino Wiring-based Framework (RPi Pico RP2040)",
+  "keywords": [
+    "framework",
+    "arduino",
+    "Cortex-M",
+    "Raspberry Pi",
+    "RP2040"
+  ],
+  "homepage": "https://arduino-pico.readthedocs.io/en/latest/",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/earlephilhower/arduino-pico"
+  }
 }