Xfbdev resolution

Forum: X and Fluxbox
Topic: Xfbdev resolution
started by: wireframewolf

Posted by wireframewolf on July 04 2007,08:19
Well, I got DSL installed onto a Libretto 110ct very easily via transplant installing, but the video was pretty screwed up. So I switched to Xfbdev, and it looks great... except that the res is way to high for the 800x480 screen, and I can't seem to change the resolution.

I tried running Xfbdev -screen 800x480x24x60(75, 85), not quite sure what the proper refresh rate is but I think it's one of those. That never quite works, as I just get a grey screen with an X for a cursor, and when I ctrl-alt-backspace out of that, I get a brief message flashed: overriden by ACPI (I think... the message is very quick).

I tried running it at first just from a terminal, and realized that I am probably trying to run one X server on top of another, which would be silly. But then I closed out the first x server and tried to run it again from the command line, but it did the same thing.

So.... can someone be kind enough to tell me how to properly change xfbdev's resolution? I'm so close to having this little guy ready to go, and I'm very excited, but I can't seem to figure this hurdle out. Help would be greatly appreciated.

Posted by curaga on July 04 2007,08:51

add a bootcode vga=808 and you will have 800x480x24bits

Posted by andrewb on July 05 2007,00:09

< http://damnsmalllinux.org/wiki/index.php/Libretto_100CT >

as well for a brief run-down on other settings useful for the L100/110 series.

I anything isn't clear let me know & I'll check the settings on my L100

Posted by wireframewolf on July 05 2007,16:20
Ah, well, I got it working. Thanks for your help. With that other post I was also able to get my sound working easily (only to realize that the audio jack is about a mm too small for a conventional plug >.>) Just out of curiosity, are you the same andewb that inhabits the Doomworld forums?
Posted by andrewb on July 05 2007,23:32
No - not me!

You may want to change the version of torsmo in DSL. v0.17 is included, but it can't access the battery status on the L100/110 series as the battery state is in a directory clled MBAT & v0.17 can only cope with names like BAT0, BAT1,... I have a binary of v0.18 wich seems to work OK on my L100, but gives a floating point exception when I use it with an emulator on WinXp. I could post this for testing, or the code is available from the sourceforge page for torsmo.

Posted by lucky13 on July 06 2007,12:21
Andrew, have you tried setting a symlink between what torsmo (0.17) is looking for and where your battery status is? Works for me on my laptop.
Posted by stupid_idiot on July 07 2007,17:17
The commands below will only work if you use a hardware-specific framebuffer module, and NOT vesafb - vesafb is what you get by default on DSL where the choice of framebuffer resolution is fixed at boot-time by boot codes such as 'vga=791'. If you want to adjust framebuffer resolution from the text console when DSL is running, you should avoid using such a boot code. However, it is not enough to simply avoid using 'vga=7xx', because vesafb will still be loaded - only it will autodetect a suitable video mode. You MUST override the loading of vesafb by using the 'vga=normal' boot code, so that no framebuffer modules whatsoever are loaded at startup. After DSL has booted up, you can modprobe the framebuffer module that matches your hardware. The available modules are found in '/lib/modules/2.4.26/kernel/drivers/video/'. Once you have decided which module is suitable, load it with `modprobe`:
`modprobe atyfb` (older ati cards up to 'rage' series)
`modprobe aty128fb` (ati 'rage128' only)
`modprobe radeonfb` (ati radeon series)
`modprobe rivafb` (nvidia cards)
etc etc.

You can adjust the framebuffer resolution from the text console using the `fbset` program. It is not very big, just a small little program. You can get the deb or the source < here >. Then, set the resolution:
`fbset -a [mode_name]`
(`-a` means to apply mode to all ttys - it's optional.
The [mode_name] comes from the textfile '/etc/fb.modes'. This file comes standard with the fbset Debian package.)

'/etc/fb.modes' contains entries like this:
mode "640x480-60"
   # D: 25.175 MHz, H: 31.469 kHz, V: 59.94 Hz
   geometry 640 480 640 480 8
   timings 39722 48 16 33 10 96 2

mode "640x480-75"
   # D: 31.50 MHz, H: 37.500 kHz, V: 75.00 Hz
   geometry 640 480 640 480 8
   timings 31747 120 16 16 1 64 3

etc etc (800x600, 1024x768, and others)

The last number in 'geometry' (8 - emphasis mine) refers to the color depth. Depths like 32, 24, and 16 can be used.
After you've edited the mode to your liking, load the mode (THIS MUST BE DONE FROM THE TEXT CONSOLE!!):
`fbset -a 1024x768-75`
The text console should switch to the mode specified.
Then start the framebuffer Xserver:
1. Select 'Xfbdev' in xsetup.sh if you have not done so.
2. `startx`

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