[coreboot] No external PCIe GPU possible/working on Gigabyte g41m-es2l

[Stefan Reinauer]

* i1w5d7gf38keg at tutanota.com <i1w5d7gf38keg at tutanota.com> [170226 21:59]:
> Hardware: Gigabyte g41m-es2l, latest coreboot git, latest seabios git, two
> nvidia gpu cards tested
> 
> I tried to use some external GPU on a g41m-es2l to get some digial screen
> output. It does not seem to work. When having build coreboot with native
> vga-init for the internal intel gpu, i never get a output from the nvidia card.
> When i connect the analog VGA cable to the internal intel gpu and boot up i can
> see many nouveau (memory-space?) errors. Both GPUs (nvidia and intel) are then
> enabled at once. Kernel 4.10 cant boot.
> 
> I tried removing the native vga-init. The only change is then that the Intel
> GPU works only when the kernel have load. Nvidia card deliver still same
> errors.
> 
> With OEM-bios the intel card gets disabled and a PCIe GPU works fine.

Please provide coreboot boot logs.

Stefan