Hi,
On Sun, Feb 10, 2019 at 2:18 PM Nico Huber nico.h@gmx.de wrote:
The usual workaround is to add a predicate that is selected by the board. e.g.
config FRAMEBUFFER_VESA_DEFAULT_118 bool choice default FRAMEBUFFER_VESA_MODE_118 ifFRAMEBUFFER_VESA_DEFAULT_118
Not pretty either, but generally accepted. src/mainboard/Kconfig starts with an example of this pattern.
Thank you very much for your advice and inspiration! I just made a new change https://review.coreboot.org/c/coreboot/+/31324 , and you are welcome for review.
I don't understand the current 117 default. I remember it was a common mode in the legacy BIOS days. But for legacy boot, you wouldn't want to run the VGA BIOS in coreboot. It might be worth to test (with all currently integrated payloads) if 118 isn't a better default. Assuming 118 means 4-byte pixels? I would expect it to be more compatible.
The main difference between 117h and 118h modes is the number of colors: 117h = 16-bit (2 byte) pixel - 64k colors, 118h = 24-bit (3-byte) pixel - 16M colors.
To be honest I don't know how the number of colors affect the compatibility, especially for the older coreboot boards, so I think the safer approach would be to leave the default as 117h while maybe choosing the other better defaults for the boards where they have been tested.
We already tested 118h mode at G505S and it's working well there, although with VGABIOS added (no native graphics init yet) :
On Sat, Nov 3, 2018 at 8:42 PM Hans Jürgen Kitter wrote: Coreboot config: std. g505s build, but both run oprom & load oprom was enabled (native mode), also display was set to FB, 1024x768 16.8M color 8:8:8, legacy VGA → this provides console output even if eg. GRUB is the payload).
( the message above is related to HJK patches for making a dGPU working at G505S, currently I'm looking through these patches and hope to upstream them in the near future)
So I'm suggesting these Kconfig options for G505S ( FRAMEBUFFER_SET_VESA_MODE and FRAMEBUFFER_VESA_DEFAULT_118 ) at another new https://review.coreboot.org/c/coreboot/+/31325 change
Best regards, Mike Banon