Framebuffer device
Wed, 2006-09-06 05:01
It started when I wanted to use the penguin logo at boot time on a Linux distro I was using . I looked for information on how to enable it and then i started to see lots of references to a "framebuffer device" but i never really understood it. I know that it is the "basic" graphics device for Linux wich does not use hardware acceleration. Is it enbled by the X? Or it is possible to use it without X? I am building my own linux distribuition with LFS (Linux From Scratch), actually i'm reading BLFS (Beyond Linux From Scratch) and i'm now installing X, does the fbdev driver has anything to do with it? Explain The whole framebuffer story to me please!
While I'm far from being an expert on this I am quite sure framebuffer is separate from X. You usually start x only after you boot up and log in while framebuffer can be used to display boot images before you actually boot (well duh!).
Maybe someone else can help further.
Btw, I'm moving this thread to "software support" forum. The "questions and suggestions" forum is for topics specific to this site. Oh and btw, welcome aboard!
The framebuffer is another name for the video output. It doesn't require X. See the Wikipedia article for more.
to enable a framebuffer console, you need to select "Framebuffer Console" and a driver (usually VESA will do fine) in Drivers/Graphics (I'm not sure of the exact name). for the penguin. you need to select "Bootup Logo" as well.
For it actually to appear, yoy need to pass a parametre vga=... to the kernel in your grub or lilo configuration file. for 1280x1024, I use vga=0x31A or vga=794 (they are equivalent). a table with these modes can be found, among other places, here
X11 can be set up to use the linux framebuffer device for output (driver "fbdev"), but usually is not due to acceleration.
THANK YOU ALL!! i'm very gratefull to you!!!
Thank you for asking.