Non-debug uarts triggering the UEFI boot gui config in Scarthgap

[conradmenchine]

Hi all, I'm running into an issue after upgrading a jetson-orin based platform to scarthgap. It seems that now during the boot process, UEFI will listen for activity on multiple (all?) uarts, and activity on a particular uart that streams data from a peripheral is now causing the device to enter the uefi config gui on boot. I assume that there must be some simple way to disable this behavior, but nothing that I've tried has worked...

Things that I've tried that have not worked

• adding a chosen configuration to the main device tree: doesn't appear to be used during UEFI?
• Setting enable_combined_uart=<0> in the mb2 dtsi: Causes boot to halt entirely
• Applying this patch to set the boot timeout to 0: Causes linux to hang for ~1 minute at the "press any key" stage, then drops into a command line interface for uefi rather than the gui

Is this something that anyone else has encountered and/or fixed? any input would be greatly appreciated.
Thanks

[cbrake]

I seem to randomly encounter this issue, and not sure exactly what triggers it. I think it might have something to do with my terminal zellij setup and stray characters getting into the serial session. But it sounds like what you are seeing is something different.

[madisongh]

If you configure your UEFI build for "single boot," the Platform boot manager (Silicon/NVIDIA/Library/PlatformBootManagerLib/PlatformBm.c in edk2-nvidia) won't listen for any keys, which should bypass the problem. The configuration I'm testing here does this. But if you actually need the boot menu, you'll need a different solution... the Kconfig file has serial port-related configs that you could try turning off, if you only need the boot menu on the video display.

[kekiefer]

The trick I use to do this is in the devicetree disable the serial ports that I wish to hide from UEFI. Then use an overlay to enable them just for linux with sw-modules = "kernel" set in the board_config.