Booting a linux kernel in vesa framebuffer mode

Useful when you want to run graphic apps using FB instead of X (like qemu.)

Add vga=0xnnn to the kernel boot options. The valid modes are listed in linux/Documentation/fb/vesafb.txt.

    | 640x480  800x600  1024x768 1280x1024
----+-------------------------------------
256 |  0x301    0x303    0x305    0x307  
32k |  0x310    0x313    0x316    0x319  
64k |  0x311    0x314    0x317    0x31A  
16M |  0x312    0x315    0x318    0x31B