Hi Chris, > I'm working with a Raspberry Pi Compute Module 5 and trying to expose a > debug UART via GPIO 8/9 (UART3 on RP1). > > In Linux this works using: > dtoverlay=uart3-pi5 > dtoverlay=stdout-uart3 > > However I cannot get U-Boot console output on these pins. > > My understanding is that access to these UARTs requires RP1 support > through the BCM2712 PCIe root complex, which does not yet appear to be > implemented in U-Boot. > > Is it currently expected that RP1 UARTs cannot be used for the U-Boot > console on Pi5 / CM5?
That is correct, ATM the uart10 which is on the main SoC is currently the only supported console option. Generally we've only supported the default console on the RPis so it's possible that even when the RP1 support lands there may be more work to be done to support non default UARTs, the driver itself is standard pl011 UART so the driver should be there. Peter
