Talos II/Two kernel GPU solution
Talos_II Two kernel GPU solution.
Until a solution can be found to take advantage of booting using the onboard AST GPU -or- a GPU you have installed in a PCIe slot this workaround can be used.
It requires building two kernels to use the same installed Linux system. When issuing the update-grub command after having located your new kernel, and initrd.img plus System.map, into the boot directory, GRUB will boot the kernel with the highest local number first. So the kernel for the PCIe slot GPU must have a higher number than the kernel for the AST chip.
For example; 4.18.12a3 = AST 4.18.12k4 = AMD
To use the AMD GPU the AST VGA jumper must be ON and you will see no video output until the login screen appears.
If you need to use the AST VGA for Petitboot functions then the VGA jumper must first be removed. You can then manually select the lower numbered kernel to boot into your system.
Instead of messing around with the jumper a mini toggle switch can be connected to the board pins and located most anywhere.
The only difference in the kernels is the selection of Graphics Driver. One will select only the AMDGPU driver and the other, lower numbered kernel, will only select the AST driver. Both kernels will have any firmware blobs needed for the AMDGPU but they will simply not be used for the AST kernel.
There is no need to make a xorg.conf.d file or to blacklist the AST.
Unfortunatly this only works for one Linux distribution on your Talos II. Additional distros will need to use the Xorg.conf.d and blacklist.