Any suggestions for troubleshooting linux embedded UEFI/slimboot boot issues?

nieknooijens

Hi all

If this is the wrong board feel free to delete it.

So, I'm having this embedded intel platform with an Intel Atom x6425RE CPU.
I compiled slimbootloader, combined and stiched it with the IFWI firmware and the UEFIBOOT.fd from the edk2 UEFIpayloadpkg, and things seem to work.

I can get an UEFI shell on my UART (pciserial, 0:30.1 / 0:1e.1 -> VID:0x8086, PID 0x4B28)

However, the moment I jump to the kernel's entry point I lose all serial output.
earlyprintk=pciserial doesn't work. I even added some code to the EFISTUB and it does print up to the point it leaves the EFI environment.

anyone having suggestions how to troubleshoot? anything is welcome!