Great job! Do you have a plan to adjust it for Platformio?

[vladkozlov69]

Hello Earle,

your codebase looks really great. Do you have a plan to adjust it for Platformio? i.e. adding board definition and platformio-specific packages/platforms?

[earlephilhower]

@vladkozlov69 I don’t use Platform IO but I do know of it from my other Arduino core.

It would be great if you or another user sent a PR for this. I know it’s not a big project, but doubt I’ll have time soon on my own to look at it.

[jhmaloney]

Has anyone else taken this on? If not, I can give it a shot.

[jhmaloney]

Unfortunately, after consulting with Valerii Koval from PlatformIO, I've concluded that this project is more than I care to take on, especially since I'd need to learn a lot about creating build scripts. I also found that PlatformIO does not want to support two Arduino Pico frameworks, so PlatformIO support for this package would be an ongoing community effort.

That said, PlatformIO does have a way to pull unsupported packages from GIT repositories, so adding PlatformIO support could still be useful. This community project has support for things that are not (yet?) in the official Arduino Pico framework, including the LittleFS and Servo libraries, which my project (MicroBlocks) depends on. My sincere thanks to Earle and others who have contributed to this package!

Here are the steps Valerii outlined, in case someone else wants to give this a go.

This integration might need a substantial amount of effort. Here are the steps I think will be needed.

First, the community package uses a custom toolchain with a very recent version of the newlib library, so it is not compatible with the toolchain used in the official Arduino core. That means that you will need to repack and upload to the PlatformIO registry all the necessary toolchains. (I assume there are also other auxiliary tools that should be uploaded (e.g. elf to uf2 converter, some python scripts etc.))

Second -- and most important -- is the build script. The Arduino IDE build logic must be adapted the PlatformIO build system API. This isn't going to be an easy task. All that logic will go to a new python file in this folder https://github.com/platformio/platform-raspberrypi/tree/develop/builder/frameworks/arduino . You can take a look at similar scripts in the STM32 platform, for example https://github.com/platformio/platform-ststm32/blob/develop/builder/frameworks/arduino/mxchip.py

Finally, you will need to implement some logic so users can switch between cores. Usually, we do this using the "build.core" option. Here is how it described in our docs for STM32:
https://docs.platformio.org/en/latest/platforms/ststm32.html#configuration

And here is the code responsible for switching cores (look how we change packages, their versions, build scripts, etc)
https://github.com/platformio/platform-ststm32/blob/develop/platform.py#L41

[earlephilhower]

@jhmaloney it may not be as bad as it sounds, but it's your call.

I based this core off of my work w/the ESP8266 Arduino core (https://github.com/esp8266/Arduino) and I have a feeling the actual build script there could be used here with minor mods. The toolchain packaging AFAIK isn't much, either, as I'm using the same GCC and newlib there and it didn't seem to be a big deal to the PIO-esp8266 maintainer.

[maxgerhardt]

I've opened the matching issue in platformio/platform-raspberrypi#13. I can actually also help with the needed builder script and PR into this repo.. they are not too difficult to write, mostly all the same with some core-specific configuration options added mostly.

[earlephilhower]

Cool, @maxgerhardt . If there are any changes, let me know! I've followed the ESP8266 tools and core packaging setup, which already supports it, so we should be more than half way there.

I'd do it myself, but I've never been able to get PIO working for me, except to build Marlin. There, it "just worked." But using a git repo instead of a d/l'd package, I could never get it to work...

[maxgerhardt]

FYI, today I've forked the core and added a builder script, along with the needed platform modifications to use your toolchain-pico and being able to do a core-selection in the platformio.ini in https://github.com/maxgerhardt/platform-raspberrypi. A test firmware repo is at https://github.com/maxgerhardt/pio-pico-core-earlephilhower-test.

The current state is that I can successfully build the firmware (with the linker script also generated by simplesub.py) and it runs :). Tested with a blinky and USB serial sketch.

There's also some ToDos left for being able to select the "partition table" / flash size options, and adding support for uploading files as e.g. supported in ESP8266 & ESP32. But overall, this won't be a big deal, most of the work is already done.

After that's done I'll PR into this repo and do the PRs for the platform-raspberrypi and the documentation, then we'll have it in mainstream PlatformIO.

[earlephilhower]

Great news! If you're feeling lucky, IIRC platformIO supports debugging and we distribute both GDB and OpenOCD in the tools tarball. But that's definitely a "nice to have" not a "need to have!" :)

Once your PR is in, I think it should be simple enough to add any platformIO specific packaging stages to the automated release process. So when I push a tag to generate a release, the CI system will generate whatever else is needed for PIO, too.

[maxgerhardt]

IIRC platformIO supports debugging and we distribute both GDB and OpenOCD in the tools tarball. But that's definitely a "nice to have" not a "need to have!" :)

Debugging support is handled on the platform level (platform-raspberrypi), independent of the framework, (Would also be cumbersome to re-add the same debugging logic / commands for every framework.) There, (here, here) it already has support for debugging via JLink (JLink.exe) and OpenOCD (with picotool, cmsis-dap, raspberrypi-swd or any other debug adapter). So that's actually automatically already there and PlatformIO already has the packages for it (with GDB being sourced from toolchain-pico then). I'll of course verify this with my own Pico :)

[maxgerhardt]

I am moving towards the final steps of the builder script refinements and platform code modifications.

It is now working that a user can specify the sketch and filesystem size in the platformio.ini, via a e.g. board_build.filesystem_size = 1M parameter. From that, the linker script input variables are calculated just like in this core.

Also I've added the code in the platform to create LittleFS images with the config that this core uses and the ability to flash those images via picotool to the device via the usual "Build Filesystem" and "Upload Filesystem" project tasks. It is all working pretty nicely :)

The final steps are making it work via OpenOCD / JLink.exe upload methods and verifying that debugging works.

[maxgerhardt]

I'm making progress regarding adding debugging support using Picoprobe, but it's not 100% working yet.

The stacktrace doesn't reach back to the actual user function (in the sketch I do Serial.printf() and the furthest in the stacktrace is SerialUART::write() and doesn't halt in e.g. setup() or loop(). Interestingly it sees both Cortex-M0+ cores as hardware threads and I can inspect them individually, with only Core 0 running a firmware for now.

PR #250 has been opened in the meantime for the builder script for this core.

EDIT: Hm interesting, changing the linker script to comment out that stuff is placed in RAM.. has caused all functions to be placed in RAM.. and with that debugging is working better.