Reducing video mode switching during Linux boot
- by Zack
When I boot up my desktop computer, which only has Linux on it, the video mode and/or console font gets switched four times:
When GRUB starts, it switches from 80x25 text to a graphical mode so it can draw a pretty background behind its menu;
GRUB then goes back to 80x25 text after I pick something from the menu;
When the KMS driver for my video card loads, it switches to a much higher-resolution text mode (I don't know if this is a hardware text mode or not);
Finally X starts and it goes graphics and stays that way. I think this last switch does not change the resolution of the video mode, only the graphicalness.
I'd like to get rid of as many of these mode switches as possible. Ideally, when GRUB takes over from the BIOS it would go directly to the same high-resolution text mode that the KMS driver selects, and the display would stay in that mode till X starts and brings up graphics. I am under the impression that this is possible by mucking with the kernel command line and/or the GRUB console module load parameters, but I don't know the details.
GRUB 1.98+20100706, kernel 2.6.32.15 using Nouveau video drivers. Distro is Debian unstable. Please no answers that involve recompiling anything or cobbling together bleeding-edge kernel/driver combinations, I don't care enough about this to go to that much trouble.
EDIT: Tobu suggests setting GRUB_GFXMODE to the full pixel resolution of the monitor, and GRUB_GFXPAYLOAD_LINUX=keep to avoid the mode switch after the menu goes away. This does part of what I want, but winds up being worse overall. There's no mode switch after the menu, but there's still a painfully-slow screen repaint (I should probably just give up on GRUB's gfxmode, it's waaaay too slow at 1920x1200). More seriously, there's now a double mode switch when nouveaufb loads, along with fun-looking error messages in dmesg
[ 5.923798] [drm] nouveau 0000:02:00.0: allocated 1920x1200 fb: 0x40250000, bo ffff8801ba5f4600
[ 5.923802] fb: conflicting fb hw usage nouveaufb vs EFI VGA - removing generic driver
[ 5.923821] [drm] nouveau 0000:02:00.0: PFIFO_INTR 0x00000010 - Ch 1
("PFIFO_INTR" message repeats 400+ times)
[ 5.925609] Console: switching to colour dummy device 80x25
[ 5.925802] Console: switching to colour frame buffer device 240x75
