Where's VESA Framebuffer module (vesafb)?

[David Becker]

I'd like to use the VESA framebuffer (vesafb), but the module doesn't seem to be present. The config for the installed kernel (2.6.20-1.2948) says Y to CONFIG_VESA_FB. Has the name changed? I'm looking for 'vesafb' but can't find it.

Thanks,

David

[RupertPupkin]

If the kernel's .config file says "Y" for CONFIG_VESA_FB then that means the vesafb driver was built directly in the kernel, not as a module. So you just have to tell the kernel to use it. On the line in your /boot/grub/grub.conf file that loads your kernel, try something like this:

kernel /vmlinuz-2.6.20-1.2948 ro root=... video=vesafb:1024x768-8@76

where the "..." part is whatever your current options are. The "1024x768-8@76" part says to run the vesafb framebuffer console at 1024x768 resolution in 8-bit color depth at a 76Hz vertical refresh rate. You may have to experiment with those numbers to get a combination that works for your video card and monitor (the ones above work for mine). Usually it's the refresh rate that you'll need to play with, I had to try several values before finding one that worked for me.

[David Becker]

Originally Posted by RupertPupkin

If the kernel's .config file says "Y" for CONFIG_VESA_FB then that means the vesafb driver was built directly in the kernel, not as a module.

You're absolutely right, I hadn't even considered that. Strange that all the other framebuffer devices are available as a module.

Originally Posted by RupertPupkin

So you just have to tell the kernel to use it. On the line in your /boot/grub/grub.conf file that loads your kernel, try something like this:

kernel /vmlinuz-2.6.20-1.2948 ro root=... video=vesafb:1024x768-8@76

where the "..." part is whatever your current options are. The "1024x768-8@76" part says to run the vesafb framebuffer console at 1024x768 resolution in 8-bit color depth at a 76Hz vertical refresh rate. You may have to experiment with those numbers to get a combination that works for your video card and monitor (the ones above work for mine). Usually it's the refresh rate that you'll need to play with, I had to try several values before finding one that worked for me.

Thanks for this. I don't understand why this particular device is builtin rather than a module. Is there another module specifically for S3 (Virge DX/GX) cards?

Thanks,

David

[RupertPupkin]

In the 2.6.20-rc2-mm1 kernel there was a patch for a new S3 framebuffer called s3fb. I don't know if that made it into the 2.6.20 kernel you're using. Look in your kernel source directory, under Documentation/fb there may be a file called s3fb.txt. If not then you're probably stuck with vesafb. The generic VESA console framebuffer should work for you, but it definitely is better to use one for your specific card. I know that the radeonfb driver I use for my Radeon 9250 is much better than vesafb.

[David Becker]

Originally Posted by RupertPupkin

In the 2.6.20-rc2-mm1 kernel there was a patch for a new S3 framebuffer called s3fb. I don't know if that made it into the 2.6.20 kernel you're using. Look in your kernel source directory, under Documentation/fb there may be a file called s3fb.txt. If not then you're probably stuck with vesafb. The generic VESA console framebuffer should work for you, but it definitely is better to use one for your specific card. I know that the radeonfb driver I use for my Radeon 9250 is much better than vesafb.

Strange that a framebuffer driver is only now being featured for such an old card (S3), though performance is not of importance.

I'd rather work with modules than configuring/enabling the fb at boot time. There's so many other module based framebuffer drivers it makes you wonder why vesa got builtin. Maybe it's unstable otherwise, who knows?

I'm using fbtv which doesn't work with VGA16 (which would be sufficient for my purposes). Any suggestions welcome on console output from v4l devices (other than setting up X).

Thanks,

David

[RupertPupkin]

My guess is that the vesafb is built in to the kernel because virtually every video card is VESA-compliant and hence can use vesafb. Also, it gives you the console framebuffer with the nice little color Tux logo at boot time, which I don't think you get by using a module, IIRC. In fact, I think the Fedora installer uses vesafb.

For fbtv to work you need a console framebuffer, period. It won't work in standard VGA16 console mode. If you don't need the framebuffer at boot time then you could just load the appropriate framebuffer module with the options I mentioned before, and then run fbtv.

[David Becker]

Originally Posted by RupertPupkin

My guess is that the vesafb is built in to the kernel because virtually every video card is VESA-compliant and hence can use vesafb. Also, it gives you the console framebuffer with the nice little color Tux logo at boot time, which I don't think you get by using a module, IIRC. In fact, I think the Fedora installer uses vesafb.

I was expecting something like this as the reason for building it into the kernel.

Originally Posted by RupertPupkin

For fbtv to work you need a console framebuffer, period. It won't work in standard VGA16 console mode. If you don't need the framebuffer at boot time then you could just load the appropriate framebuffer module with the options I mentioned before, and then run fbtv.

Forgive me but isn't the VGA16 (vga16fb) a console framebuffer?

The problem is that there doesn't seem to be an appropriate framebuffer module at hand for the S3 card. The closest (module) was VGA16 but fbtv complains 'can handle only packed pixel frame buffers' . The vesafb will probably work but requires a reboot to change settings or enable/disable the framebuffer.

All I want to do is output a webcam picture to change the focus. I used to do this with a matrox g400 card which is well supported and for which a module exists. Regretfully that card is in another machine.

Many roads lead to Rome. Is there an easier route to focusing a webcam?

Thanks,

David