dmpogo
Advocate
Joined: 02 Sep 2004
Posts: 3468
Location: Canada
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 Posted: Thu Feb 15, 2024 1:42 am Post subject: Framebuffer at boot and tty, grub etc. |
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I have a rather ancient desktop connect to more modern display having issues with resolution during boot process, and on getty terminals later on.
Desktop has NVIDIA Geforce 8500 which maximum supported resolution is 1920x1200, which is connected via DVI link to 16:9 aspect DELL monitor with native resolutions of 2560x1440
Here is the output of xrandr, which supposedly shows something about the monitor EDID
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Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 8192 x 8192
DVI-I-0 disconnected primary (normal left inverted right x axis y axis)
VGA-0 disconnected (normal left inverted right x axis y axis)
TV-0 disconnected (normal left inverted right x axis y axis)
DVI-I-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 600mm x 340mm
2560x1440 59.95 +
1920x1200 59.88
1920x1080 60.00*
1680x1050 59.95
1600x1200 60.00
1280x1024 75.02 60.02
1280x800 59.81
1152x864 75.00
1024x768 75.03 60.00
800x600 75.00 60.32
640x480 75.00 59.94
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Kernel is compiled with VESA framebuffer, and the card shows the following framebuffer modes
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# hwinfo --framebuffer
02: None 00.0: 11001 VESA Framebuffer
[Created at bios.459]
Unique ID: rdCR.OqaYRAmdZv6
Hardware Class: framebuffer
Model: "NVIDIA G86 Board - p403h20"
Vendor: "NVIDIA Corporation"
Device: "G86 Board - p403h20"
SubVendor: "NVIDIA"
SubDevice:
Revision: "Chip Rev"
Memory Size: 14 MB
Memory Range: 0x01000000-0x01dfffff (rw)
Mode 0x0300: 640x400 (+640), 8 bits
Mode 0x0301: 640x480 (+640), 8 bits
Mode 0x0303: 800x600 (+800), 8 bits
Mode 0x0305: 1024x768 (+1024), 8 bits
Mode 0x0307: 1280x1024 (+1280), 8 bits
Mode 0x030e: 320x200 (+640), 16 bits
Mode 0x030f: 320x200 (+1280), 24 bits
Mode 0x0311: 640x480 (+1280), 16 bits
Mode 0x0312: 640x480 (+2560), 24 bits
Mode 0x0314: 800x600 (+1600), 16 bits
Mode 0x0315: 800x600 (+3200), 24 bits
Mode 0x0317: 1024x768 (+2048), 16 bits
Mode 0x0318: 1024x768 (+4096), 24 bits
Mode 0x031a: 1280x1024 (+2560), 16 bits
Mode 0x031b: 1280x1024 (+5120), 24 bits
Mode 0x0330: 320x200 (+320), 8 bits
Mode 0x0331: 320x400 (+320), 8 bits
Mode 0x0332: 320x400 (+640), 16 bits
Mode 0x0333: 320x400 (+1280), 24 bits
Mode 0x0334: 320x240 (+320), 8 bits
Mode 0x0335: 320x240 (+640), 16 bits
Mode 0x0336: 320x240 (+1280), 24 bits
Mode 0x033d: 640x400 (+1280), 16 bits
Mode 0x033e: 640x400 (+2560), 24 bits
Mode 0x0345: 1600x1200 (+1600), 8 bits
Mode 0x0346: 1600x1200 (+3200), 16 bits
Mode 0x0347: 1400x1050 (+1400), 8 bits
Mode 0x0348: 1400x1050 (+2800), 16 bits
Mode 0x0349: 1400x1050 (+5600), 24 bits
Mode 0x034a: 1600x1200 (+6400), 24 bits
Mode 0x0352: 2048x1536 (+8192), 24 bits
Mode 0x0360: 1280x800 (+1280), 8 bits
Mode 0x0361: 1280x800 (+5120), 24 bits
Mode 0x0362: 768x480 (+768), 8 bits
Mode 0x0364: 1440x900 (+1440), 8 bits
Mode 0x0365: 1440x900 (+5760), 24 bits
Mode 0x0368: 1680x1050 (+1680), 8 bits
Mode 0x0369: 1680x1050 (+6720), 24 bits
Mode 0x037c: 1920x1200 (+1920), 8 bits
Mode 0x037d: 1920x1200 (+7680), 24bits
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As can be seem, X is set to 1920x1080 and everything is working fine under X
But not at boot.
1) The dispay at POST is readable, but not properly working. You can read BIOS settings, but forground is flickering and purple, same as when I set X mode beyond card capability
This is at the level of driver in firmware and probably can't be helped
2) However same happens when grub takes over, and then sets the console and terminal. I would like to be able to solve it as close to POST issues as possible and is failing.
When I condifure grub to use any mode that is present in both lists, such as 1280x800, I can read the text, but on flickering background. Chaniging the mode changes the size of the text (so it works), but background still flickers. It flickkers even in pure console text mode. Only X displays properly.
What could be the idea with setting framebuffer to initialize display properly ? ( I am overall confused of what is responsible for what here)
PS, sometime in the past with earlier kernels same setup gave proper text tty's without flicker/purple hint.
It all looks like display is always in its native resolution, which is beyong card capability. |
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Kernel & Hardware
