Add STM32C0x

[Apehaenger]

In relation to #1187, I tried to add STM32C011F6P6 support for a custom PCB.

Well, somehow hard for an ungifted to jump into the internals, who's intention was to use modm for his project ;-)
However, can't become more dumb by trying :-)

Unfortunately I got stuck after a couple of lines and don't know if I missed something to hack in modm or if I made something wrong with my minimal blink example :-/
If I chose a supported MCU it compiles well, but all supported MCU's I found, do also have a board, so...

This is what I get now:

jebeling@lt-je:~/Development/OpenMowerProject/xESC_YF_rev4-adapter/firmware/ext/modm/examples/stm32c0x1/blink$ lbuild build
>> modm: Recomputing device cache...

ERROR: In 'modm:build':

Traceback (most recent call last):
  File "/home/jebeling/Development/OpenMowerProject/xESC_YF_rev4-adapter/firmware/ext/modm/tools/build_script_generator/module.lb", line 251, in post_build
    all_rams = [m for m in linkerscript.get("memories") if "w" in m["access"]]
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: 'NoneType' object is not iterable

Any hints are welcome ;-)

[salkinium]

You were just missing a dependency on modm:platform:core. That pulls in the startup code etc. Now there is a bunch of compile errors with RCC macros, the modm:platform:rcc module needs to be fixed.

[rleh]

I just created a commit very similar to 89d75c1, but was 30 seconds too late pushing it here 😆

[Apehaenger]

Many thanks for your great help @salkinium and @rleh !!
Will go on trying to fix the compile errors ;-)

[salkinium]

I was kinda wondering why RCC even gets pulled in for your minimal example, and for some reason the modm:platform:gpio module depends on RCC but doesn't use it? It's only required for the delay boot frequencies:

arm-none-eabi/bin/ld: modm/build/stm32c0x1/blink/scons-release/modm/libmodm.a(delay_ns.o): in function `modm::delay_us(unsigned long)':
./modm/src/modm/platform/core/delay_ns.cpp:54: undefined reference to `modm::platform::delay_fcpu_MHz'
arm-none-eabi/bin/ld: ./modm/src/modm/platform/core/delay_ns.cpp:54: undefined reference to `modm::platform::delay_ns_per_loop'

So I defined them in the main.cpp file as a hack, just to get you unblocked for blinky. Would probably still be good to have the RCC module to go up to 48MHz and not stay at 16MHz boot frequency.

[salkinium]

Btw, you can check the dependency graph with lbuild dependencies | dot -Tsvg -Grankdir=BT -o dependencies.svg for the example.

[Apehaenger]

Quite thanks for your quick and helpful suggestions!!

But you're to fast for me or I'm to slow/untalented.

In between I got blinky compiled well but I'm still to unfamiliar with modm and go by the docs step by step.
I currently hang with the basics :-/ scons program https://modm.io/guide/custom-project/#generate-compile-and-upload which drops me "Error: Debug Adapter has to be specified, see "adapter driver" command".

For sure, I do know how to flash the elf file with OpenOCD by hand, but thought to go the modm way, before switching over to CMake and VSCode. So still searching ;-) Turns out that the official OpenOCD 0.12.x doesn't has C0x support. My fault ;-) ... it's running now.

Yes sure! Once I get code running on it, I will try to fix the RCC issues. I also need to adapt the modules/driver for timer, uart, ADC, because my PCB needs them ;-)

Also quite thanks for hinting me to the dependency SVG. Already built one before (during work through the docs), but was shocked in the first view :-) ... but I'm pretty sure once I get it running, it will be helpful!!

[salkinium]

Did you close this on purpose? If you want to add more changes to the PR, just push more commits to the branch, the PR will update automatically.

[Apehaenger]

Yes ;-) due to frustration...
But 1/2 hour later I felt as looser and reviewed where I stuck.
Now I'm on track again... don't know if it's the right one :-) but if it's a step forward, I'll reopen and push my findings ;-)

[Apehaenger]

Okay, hard time but more clever now :-) ... or more hacky :-/

• Got RCC compile errors fixed
• stripped down my blinky sample (renamed the folder to STM32C0x)
• removed @salkinium WIP hack

As I did not know anything about modm before, I'm pretty sure that I did it somehow wrong at some places.
I also do not know if it's running at 48MHz in real or still at 16MHz boot frequency.
So please be so kind and give me a hint what should be changed.

Some questions popped up during coding:

1. If I go on and get my required drivers running for C0x, then the overview page with the supported MCUs also need to get updated (by me). I already recognized the circle sign of untested features, but how's about internal stuff like non-tested external clock or the requirement for ST's OpenOCD variant? Does such info get written down somewhere or doesn't it matter?
2. During watching around whats up with my code, I saw that the board definitions do a couple of initialization. How is it with a custom PCB like mine. Do I need to do such initialization (in special sysclock) in my main or is there some kind of custom board definition possibility which I overlooked in the docs? Yes, found modules.md in boards section which cleanly answers this question
3. What's up with the CI errors. Are they reasoned by my changes? yes

[Apehaenger]

"c0" requires an empty array for not walking through %% for id in pll_ids in rcc.cpp.in.
Is [""] a correct option?

[Apehaenger]

Reverted a couple of previous RCC hacks (like hsi48) because I felt they're wrong.

Added a custom-board.hpp to the blinky sample because I had the impression that SysClock need to be enabled/activated as ref-docs say boot frequency is HSI (48MHz) divided by 4 which is 12MHz.

But failed in RCC with PLL definitions because I'm to unknown.
Have the impression that modm-devices doesn't parsed the PLL defines out of the CMSIS header correctly, as I couldn't find any PLL defines in stm32c0x header files.

Blinky is running with a 2 second delay (instead of 0.5s), which seem to be the 1/2 boot frequency of 48MHz.

Would be nice if someone can give me a hint ;-)

[salkinium]

I'll have a look next week in more detail when I'm on holiday, under the week I'm typically too mentally exhausted from work.

[Apehaenger]

In between I did some tries with STM32CubeMX together with STM32-VScode extension. This is not an option for me 👎
So I reverted back to my initial but wrong looking 'hsi48' hacks, because it work and also the delay look correct.

With this I can go on trying to get into my project and use modm for it 👍

So @salkinium, enjoy your holiday by reading a book or doing something funny, but don't with coding. My issue has time for somewhen after holiday!

[salkinium]

I ordered a NUCLEO-C031C6 dev board, will probably end of week. I also found a super cheap (~1.5CHF) STM32C011 barebone dev board on aliexpress, but that'll arrive later.

[Apehaenger]

Oh no, don't waste money for my dev issues.
I'm pretty happy at the moment and get step by step into modm. Trying all driver (and partly build examples) which I do need for my project.
All is working great at the moment. Also sysclock stuff is working as expected since I added the HsiSysDivider stuff.
The bigger question will be: If I made it right and if it fit to your code requirements ;-)

Edit:
Took me some time to realize that the C0x doesn't has a PLL. Since that got into my brain, I'm going forward without issues 👍

[salkinium]

It's more to have a device to run the modm unit tests on. The nucleo boards are super cheap, and I need at least one device per family anyways.

[Apehaenger]

This is non-sense ATM