third_party.pigweed.src/targets/arduino/target_docs.rst
Michael Spang c8b939009b Remove absolute paths from build command lines
The GN convention is to specify paths in command lines relative to the
build directory. Unfortunately and contrary to pigweed's expectations
this is not what rebase_path(path) does; that outputs an absolute path.

Absolute paths are not desirable in most circumstances as they contain
sources of nondeterminism such as the developer's home directory. Using
them can for example reduce hit rate in build caches.

Replace rebase_path(path) with rebase_path(path, root_build_dir) which
is the correct idiom and matches GN's builtin behavior (e.g. for
sources, include_dirs, etc).

This also removes the --directory argument to python_action(). Changing
the directory during the build while using relative paths is likely to
result in confusion and should be discouraged.

There's a couple more things to do on top of this for identical
binaries between build directories / machines / developers:

- pass options to avoid embedding the working directory
- pass options to use relative paths for the vendored clang & libc++

See [1]-[2] for how to do that.

[1] https://source.chromium.org/chromium/chromium/src/+/main:build/config/compiler/BUILD.gn;l=1170-1239;drc=ab531c265c533cba1c2f6d8240cc0bf7679f605a
[2] https://cs.opensource.google/fuchsia/fuchsia/+/main:build/config/BUILD.gn;l=145-216;drc=f6d705f0937c778d5d5f807a4580113612b02f5a

Change-Id: I17708102c03d6488d68c8571b6e9343191fd47de
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/47461
Reviewed-by: Wyatt Hepler <hepler@google.com>
Commit-Queue: Michael Spang <spang@google.com>
2021-06-09 19:15:51 +00:00

259 lines
11 KiB
ReStructuredText

.. _target-arduino:
-------
Arduino
-------
This target supports building Pigweed on a few Arduino cores.
.. seealso::
There are a few caveats when running Pigweed on top of the Arduino API. See
:ref:`module-pw_arduino_build` for details.
Supported Boards
================
Currently only Teensy 4.x and 3.x boards are supported.
+------------------------------------------------------------------+-------------------------------------------------------------------+-----------+----------+-------------+
| Core | Board Name | Compiling | Flashing | Test Runner |
+==================================================================+===================================================================+===========+==========+=============+
| `teensy <https://www.pjrc.com/teensy/td_download.html>`_ | `Teensy 4.1 <https://www.pjrc.com/store/teensy41.html>`_ | ✓ | ✓ | ✓ |
+------------------------------------------------------------------+-------------------------------------------------------------------+-----------+----------+-------------+
| `teensy <https://www.pjrc.com/teensy/td_download.html>`_ | `Teensy 4.0 <https://www.pjrc.com/store/teensy40.html>`_ | ✓ | ✓ | ✓ |
+------------------------------------------------------------------+-------------------------------------------------------------------+-----------+----------+-------------+
| `teensy <https://www.pjrc.com/teensy/td_download.html>`_ | `Teensy 3.6 <https://www.pjrc.com/store/teensy36.html>`_ | ✓ | ✓ | ✓ |
+------------------------------------------------------------------+-------------------------------------------------------------------+-----------+----------+-------------+
| `teensy <https://www.pjrc.com/teensy/td_download.html>`_ | `Teensy 3.5 <https://www.pjrc.com/store/teensy35.html>`_ | ✓ | ✓ | ✓ |
+------------------------------------------------------------------+-------------------------------------------------------------------+-----------+----------+-------------+
| `teensy <https://www.pjrc.com/teensy/td_download.html>`_ | `Teensy 3.2 <https://www.pjrc.com/store/teensy32.html>`_ | ✓ | ✓ | ✓ |
+------------------------------------------------------------------+-------------------------------------------------------------------+-----------+----------+-------------+
| `arduino-samd <https://github.com/arduino/ArduinoCore-samd>`_ | `Arduino Zero <https://store.arduino.cc/usa/arduino-zero>`_ | | | |
+------------------------------------------------------------------+-------------------------------------------------------------------+-----------+----------+-------------+
| `arduino-sam <https://github.com/arduino/ArduinoCore-sam>`_ | `Arduino Due <https://store.arduino.cc/usa/due>`_ | | | |
+------------------------------------------------------------------+-------------------------------------------------------------------+-----------+----------+-------------+
| `adafruit-samd <https://github.com/adafruit/ArduinoCore-samd>`_ | `Adafruit Feather M0 <https://www.adafruit.com/?q=feather+m0>`_ | | | |
+------------------------------------------------------------------+-------------------------------------------------------------------+-----------+----------+-------------+
| `adafruit-samd <https://github.com/adafruit/ArduinoCore-samd>`_ | `Adafruit SAMD51 Boards <https://www.adafruit.com/category/952>`_ | | | |
+------------------------------------------------------------------+-------------------------------------------------------------------+-----------+----------+-------------+
| `stm32duino <https://github.com/stm32duino/Arduino_Core_STM32>`_ | | | | |
+------------------------------------------------------------------+-------------------------------------------------------------------+-----------+----------+-------------+
Setup
=====
You must first install an Arduino core or let Pigweed know where you have cores
installed using the ``pw_arduino_build_CORE_PATH`` build arg.
Installing Arduino Cores
------------------------
The ``arduino_builder`` utility can install Arduino cores automatically. It's
recommended to install them to into ``third_party/arduino/cores/``.
.. code:: sh
# Setup pigweed environment.
source activate.sh
# Install an arduino core
arduino_builder install-core --prefix ./third_party/arduino/cores/ --core-name teensy
Building
========
To build for this Pigweed target, simply build the top-level "arduino" Ninja
target. You can set Arduino build options using ``gn args out`` or by running:
.. code:: sh
gn gen out --args='
pw_arduino_build_CORE_PATH="//third_party/arduino/cores"
pw_arduino_build_CORE_NAME="teensy"
pw_arduino_build_PACKAGE_NAME="teensy/avr"
pw_arduino_build_BOARD="teensy40"
pw_arduino_build_MENU_OPTIONS=["menu.usb.serial", "menu.keys.en-us"]'
On a Windows machine it's easier to run:
.. code:: sh
gn args out
That will open a text file where you can paste the args in:
.. code:: text
pw_arduino_build_CORE_PATH = "//third_party/arduino/cores"
pw_arduino_build_CORE_NAME = "teensy"
pw_arduino_build_PACKAGE_NAME="teensy/avr"
pw_arduino_build_BOARD = "teensy40"
pw_arduino_build_MENU_OPTIONS = ["menu.usb.serial", "menu.keys.en-us"]
Save the file and close the text editor.
Then build with:
.. code:: sh
ninja -C out arduino
To see supported boards and Arduino menu options for a given core:
.. code:: sh
arduino_builder --arduino-package-path ./third_party/arduino/cores/teensy \
--arduino-package-name teensy/avr \
list-boards
.. code:: text
Board Name Description
teensy41 Teensy 4.1
teensy40 Teensy 4.0
teensy36 Teensy 3.6
teensy35 Teensy 3.5
teensy31 Teensy 3.2 / 3.1
You may wish to set different arduino build options in
``pw_arduino_build_MENU_OPTIONS``. Run this to see what's available for your core:
.. code:: sh
arduino_builder --arduino-package-path ./third_party/arduino/cores/teensy \
--arduino-package-name teensy/avr \
list-menu-options --board teensy40
That will show all menu options that can be added to ``gn args out``.
.. code:: text
All Options
----------------------------------------------------------------
menu.usb.serial Serial
menu.usb.serial2 Dual Serial
menu.usb.serial3 Triple Serial
menu.usb.keyboard Keyboard
menu.usb.touch Keyboard + Touch Screen
menu.usb.hidtouch Keyboard + Mouse + Touch Screen
menu.usb.hid Keyboard + Mouse + Joystick
menu.usb.serialhid Serial + Keyboard + Mouse + Joystick
menu.usb.midi MIDI
...
Default Options
--------------------------------------
menu.usb.serial Serial
menu.speed.600 600 MHz
menu.opt.o2std Faster
menu.keys.en-us US English
Testing
=======
When working in upstream Pigweed, building this target will build all Pigweed
modules' unit tests. These tests can be run on-device in a few different ways.
Run a unit test
---------------
If using ``out`` as a build directory, tests will be located in
``out/arduino_debug/obj/[module name]/[test_name].elf``.
Tests can be flashed and run using the `arduino_unit_test_runner` tool. Here is
a sample bash script to run all tests on a Linux machine.
.. code:: sh
#!/bin/bash
gn gen out --export-compile-commands \
--args='pw_arduino_build_CORE_PATH="//third_party/arduino/cores"
pw_arduino_build_CORE_NAME="teensy"
pw_arduino_build_PACKAGE_NAME="teensy/avr"
pw_arduino_build_BOARD="teensy40"
pw_arduino_build_MENU_OPTIONS=["menu.usb.serial", "menu.keys.en-us"]' && \
ninja -C out arduino
for f in $(find out/arduino_debug/obj/ -iname "*.elf"); do
arduino_unit_test_runner --verbose \
--config-file ./out/arduino_debug/gen/arduino_builder_config.json \
--upload-tool teensyloader \
out/arduino_debug/obj/pw_string/test/format_test.elf
done
Using the test server
---------------------
Tests may also be run using the `pw_arduino_use_test_server = true` GN arg.
The server must be run with an `arduino_builder` config file so it can locate
the correct Arduino core, compiler path, and Arduino board used.
.. code:: sh
arduino_test_server --verbose \
--config-file ./out/arduino_debug/gen/arduino_builder_config.json
.. TODO(tonymd): Flesh out this section similar to the stm32f429i target docs.
Flashing Known Issues
---------------------
Teensy Boards
^^^^^^^^^^^^^
By default Teensyduino uses the `Teensy Loader Application
<https://www.pjrc.com/teensy/loader.html>`_ which has a couple limitations:
- Requires a GUI (or X11 on Linux).
- Can only flash one board at a time.
GN Target Example
=================
Here is an example `pw_executable` gn rule that includes some Teensyduino
libraries.
.. code:: text
import("//build_overrides/pigweed.gni")
import("$dir_pw_arduino_build/arduino.gni")
import("$dir_pw_build/target_types.gni")
_library_args = [
"--library-path",
rebase_path(arduino_core_library_path, root_build_dir),
"--library-names",
"Time",
"Wire",
]
pw_executable("my_app") {
# All Library Sources
_library_c_files = exec_script(
arduino_builder_script,
arduino_show_command_args + _library_args + [
"--library-c-files"
],
"list lines")
_library_cpp_files = exec_script(
arduino_builder_script,
arduino_show_command_args + _library_args + [
"--library-cpp-files"
],
"list lines")
sources = [ "main.cc" ] + _library_c_files + _library_cpp_files
deps = [
"$dir_pw_hex_dump",
"$dir_pw_log",
"$dir_pw_string",
]
include_dirs = exec_script(arduino_builder_script,
arduino_show_command_args + _library_args +
[ "--library-include-dirs" ],
"list lines")
# Required for using Arduino.h and any Arduino API functions
remove_configs = [ "$dir_pw_build:strict_warnings" ]
deps += [ "$dir_pw_third_party/arduino:arduino_core_sources" ]
}