Add basic esp32p4 support

[playfulFence]

Submission Checklist 📝

• I have updated existing examples or added new ones (if applicable).
• I have used cargo xtask fmt-packages command to ensure that all changed code is formatted correctly.
• My changes were added to the CHANGELOG.md in the proper section.
• I have added necessary changes to user code to the Migration Guide.
• My changes are in accordance to the esp-rs API guidelines

Extra:

• I have read the CONTRIBUTING.md guide and followed its instructions.

Pull Request Details 📖

Description

For now, there're still some TODOs left. They'll be incrementally removed as p4 support grows. For example, for now some of checks in CI are off, some code sections and so on.

related to #2285

⚠️ Before merging this PR, make sure that esp-rs/esp-pacs#301 is landed too

Testing

advanced_serial example, some more basic tests like:

//% CHIPS: esp32p4

#![no_std]
#![no_main]

use esp_backtrace as _;
use esp_hal::prelude::*;

#[entry]
fn main() -> ! {
    esp_println::println!("Hello world, from ESP32-P4 :)");

    loop {}
}

[jessebraham]

I don't think we want to include this in this release, so converting to draft for now.

[MabezDev]

Thanks! I have some initial comments, mostly around the maintainability of adding more support in the future - we don't want to spend a bunch of time working on something only to realise the function that should be doing something is stubbed out to do nothing :D.

I'll dig out my P4 rev1 board and try the examples soon.

[playfulFence]

Regarding dma stuff: currently we have a lot of drivers which are tightly coupled to dma. UART is one of them, create_peripheral macro as well, so as soon as you exclude gdma from metadata, you'll immediately get an unknown amount of errors.

[bugadani]

Yeah let's have those errors, I'll move PeripheralMarker to a better place. Alternatively, you could define an axi_gdma and ahb_gdma symbol pair, and cfg-enable dma for those without gdma/pdma parts.

[MabezDev]

Did systimer and timg work out of the box? Can we enable the examples/tests(I know we can't run them yet) for them?

[playfulFence]

I think we can get the examples to even work, but we need to implement interrupt handling. I'm starting to do that right now.

[MabezDev]

Nit pick: We probably still want to use the stub for other chips, can we duplicate this and specify target = "riscv32imafc-unknown-none-elf" to only pass --no-stub on the P4?

[playfulFence]

Honestly, I'm not even sure why is it there.
It doesn't affect a program run/flash in any sense 🤷

[playfulFence]

At this point we're getting this panic message when trying to work with interrupts on esp32p4

In general, the interrupts functionality is implemented and works, if you uncomment the code in the _start_trap_rust_hal function, everything will be pretty much fully operational. In actual state, esp32p4 gets inside the above mentioned function even when interrupt is not jumping to the vec handlers from esp-riscv-rt. I have tried to modify the vector_table as needed, however it still does not work properly.

I will switch to other work for now, will come back here a little later. In case someone wants to work on this, you're welcome too!