Opened 5 years ago

Last modified 3 months ago

#10570 new enhancement

Native video mode with VESA through vesa bios live patching

Reported by: pulkomandy Owned by: nobody
Priority: normal Milestone: Unscheduled
Component: Drivers/Graphics/VESA Version: R1/Development
Keywords: PatchVBios Cc:
Blocked By: Blocking:
Has a Patch: no Platform: All

Description (last modified by diver)

This is a trick used in the Clover bootloader to get native video modes from VESA. The idea is to patch the VESA BIOS (which is shadowed in RAM) and replace the video mode tables with the EDID data.

This gets native video mode on ATI, NVidia and Intel cards, without the need to write an actual driver. Their Vesa BIOS is smart enough to accept any resolution in the table.

http://forum.voodooprojects.org/index.php/topic,1227.0.html

http://sourceforge.net/p/cloverefiboot/code/HEAD/tree/BiosVideo/

Change History (5)

comment:1 Changed 5 years ago by diver

Description: modified (diff)

comment:2 Changed 2 years ago by waddlesplash

Component: Drivers/GraphicsDrivers/Graphics/VESA
Keywords: PatchVBios added

comment:4 Changed 3 months ago by waddlesplash

Ha, it seems the VBE driver for NewOS that was donated to us (but left unused) in #7172 supports this also.

comment:5 Changed 3 months ago by pulkomandy

Note that the support is for specific BIOS kinds (one has to know how the resolutions are encoded to find what looks reasonably like modelines in the BIOS), I guess that driver only supports old nVidia cards. So the code in Clover is probably more useful these days?

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