Add a build flag to disable specific USART IRQ handlers defined in the core

[Santynolo]

Is your feature request/improvement related to a problem? Please describe.

Without a way to undefine specific USARTx_IRQHandlers defined in the core, custom implementations of USART while keeping Serial functionality in others is not possible.

Describe the solution you'd like

I would like an additional build flag like "HAL_DISABLE_USART2IRQHANDLER" to disable specific USARTx_IRQHandler functions that are defined in the core, so they can be defined in the user's code instead, while keeping other USARTx_IRQHandler definitions to be able to use HardwareSerial on them.

Additional context
Here's a photo of the USART2_IRQHandler. For example, i would like to disable this specific handler, so i can use my own definition in my code, to write a custom use case, and be able to leave USART1 as is, so i can use HardwareSerial to print messages to the monitor.

Here is my suggested implementation: (I do not know if this will cause issues)

Thanks. This could also be implemented in other IRQHandlers, for example to disable specific ADC IRQHandlers, without disabling the entire ADC arduino implementation.

[fpistm]

Hi @Santynolo
I see why but don't like the fact to mix Arduino and pure HAL.
Anyway feel free to provide a PR.

[Santynolo]

I would like to but i'm wondering if my suggested implementation can cause issues. If not i'll do it

[fpistm]

What is your goal exactly?

[Santynolo]

I have a custom USART2 and USART3 implementation that uses a clock signal. I need access to the IRQHandlers because the way they're implemented in the core it only services UART, and not USART.

Here you can see that the core is using HAL_UART_IRQHandler instead of HAL_USART_IRQHandler. This causes a hang on my MCU (STM32G431RBT6). The only way i found to fix this hang is to undefine this snippet and use my own implementation here:

(Ignore the fact it's USART3 for now it's the quickest example i had)
This fixes the hang and my MCU is no longer reset by the watchdog.
I also need to keep the HardwareSerial class working because i use USART1 as my debugging serial port, and i use another library that needs the class for debugging. (SimpleFOC)

Another possible fix would be a build flag that leaves the USART2_IRQHandler definition, but allows it to switch from HAL_UART_IRQHandler to HAL_USART_IRQHandler