How hard would it be to add support for my stm32f411e-discovery board?

[otac0n]

I have the board but I cannot get it to run Arduino in PlatformIO, and my understanding is that adding it to stm32duino would be the correct way to add support.

[fpistm]

Hi @otac0n
I guess you talk about this one: https://www.st.com/en/evaluation-tools/32f411ediscovery.html
You can start by this:
https://github.com/stm32duino/Arduino_Core_STM32/wiki/Add-a-new-variant-%28board%29
To first add the generic from this folder:
https://github.com/stm32duino/Arduino_Core_STM32/tree/main/variants/STM32F4xx/F411V(C-E)T

[otac0n]

When I try to create a generic layout, the STM32CubeMX cannot find a clock solution for any configuration without an external input frequency. It basically says that PLL Source Mux should be HSE.

Should I enable HSE for the generic board or should I try to ignore the warning given that it reaches 48MHz for USB, etc.