Feat: Add uart support

[Dzarda7]

Description

This PR adds support for UART and makes soc_utils.h part of public API as we need it in esp-flasher-stub.

Testing

Tested with esp-flasher-stub. Receive in interrupt and response works.

Checklist

Before submitting a Pull Request, please ensure the following:

• 🚨 This PR does not introduce breaking changes.
• All CI checks (GH Actions) pass.
• Documentation is updated as needed.
• Tests are updated or added as necessary.
• Code is well-commented, especially in complex areas.
• Git history is clean — commits are squashed to the minimum necessary.

[github-actions]

Warnings

⚠️

Some issues found for the commit messages in this PR: the commit message "Apply automatic fixes from pre-commit hooks": summary looks empty type/action looks empty the commit message "feat: Add UART support": summary looks too short Please fix these commit messages - here are some basic tips: follow Conventional Commits style correct format of commit message should be: <type/action>(<scope/component>): <summary>, for example fix(esp32): Fixed startup timeout issue allowed types are: change,ci,docs,feat,fix,refactor,remove,revert,test sufficiently descriptive message summary should be between 20 to 72 characters and start with upper case letter avoid Jira references in commit messages (unavailable/irrelevant for our customers) TIP: Install pre-commit hooks and run this check when committing (uses the Conventional Precommit Linter).

	Messages
📖	You might consider squashing your 3 commits (simplifying branch history).
📖	This PR seems to be quite large (total lines of code: 2044), you might consider splitting it into smaller PRs

👋 Hello Dzarda7, we appreciate your contribution to this project!

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[Dzarda7]

@antmak @erhankur WDYT? I implemented only the stuff we need, feel free to suggest changes or request other features. Few things that came to my mind during this:

• I am wondering what to use from ROM and what to implement again as for example uart_tx_switch changes where uart_tx_one_char sends data.
• Should we move UART related rom wrapper functions move to uart.h?
• There will be many functions (not only UART ones) that are common across most of the chips, only with different registers and I believe it is not good to define them for all chips and I would like to avoid using many ifdefs. Did you already talk about the way you want to solve this? I have some ideas (weak functions or some kind of structure with pointers to functions), just making sure to not do something you already decided on.

Thanks!

[erhankur]

@Dzarda7 check it out. #31

Similar to your proposal in esp-flasher-stub PR.

[erhankur]

@Dzarda7 #32
I can't add you as a reviewer.

[Dzarda7]

Similar to your proposal in esp-flasher-stub PR.

Thanks, yes, that is exactly what I meant. We might want to adapt the runtime approach for some functions too I believe, for example large vs normal flashing, but there might be simpler solution for that, we will see.

I can't add you as a reviewer.

Yes, the issue is that I have no role in this repo. Thanks for letting me know.

[antmak]

@Dzarda7

In view of #32 some points become clearer

I am wondering what to use from ROM and what to implement again as for example uart_tx_switch changes where uart_tx_one_char sends data.

I'm not aware many details, but I'd take newer chips into account, as their implementation is usually more mature. So looks good to implement things in common/, the rest in chip-specific dirs. Although during development, it may be convenient to implement some chips and then extract common parts.

Should we move UART related rom wrapper functions move to uart.h?

If it is not a stub-lib interface, then it makes sense