On 03.01.19 09:24, galla rao wrote:
Video Mode in Coreboot
coreboot video frame buffer information
0x400 x 0x300 is exactly 1024x768.
GOP UEFI driver (Tiano payload) is expected to report 4 modes
GOP should report MaxMode 4 *0:
1600x900 BGRReserved Pixels 1600 1:
640x480 BGRReserved Pixels 640 2:
800x600 BGRReserved Pixels 800 3:
1024x768 BGRReserved Pixels 1024
Unlike legacy firmware, coreboot doesn't stay active after handing
execution over to its payload. So there is no coreboot code that
could change to a different mode afterwards. If you have to switch
modes in Tianocore, you should disable the coreboot framebuffer and
add a GOP driver to Tianocore instead.
With open-source graphics init, you could also set a fixed mode in
coreboot. Alas, there is no open-source solution for Bay Trail that
I know of. Though, existing solutions (e.g. libgfxinit) for other
Intel platforms could be extended for Bay Trail (and could also be
used to write an open-source GOP driver).