The Linux framebuffer provides a direct access to graphic cards from the linux kernel.
Support for the framebuffer is made at kernel configuration time. Configuration of the framebuffer in Gentoo is done with
cd /usr/src/linux
make menuconfig
There, in the kernel configuration menus choose:
Code maturity level options --->
[*] Prompt for development and/or incomplete code/drivers
Processor type and features --->
[*] MTRR (Memory Type Range Register) support
Device Drivers --->
Block devices --->
<*> Loopback device support
<*> RAM disk support
(4096) Default RAM disk size
[*] Initial RAM disk (initrd) support
Graphics support --->
[*] Support for frame buffer devices
[*] VESA VGA graphics support
Console display driver support --->
[*] Video mode selection support
<*> Framebuffer Console support
After this configuration step, compile the kernel and reboot:
make && make modules_install (incremental system update)
make clean bzImage modules (fresh system)
mount /boot/
cp arch/i386/boot/bzImage /boot/
cp System.map /boot/
cp .config /boot/config
lilo
reboot
You can check your video mode boot information with:
dmesg | grep vesa
You can check your video mode with:
fbset
You might have to emerge fbset first.
You can't change video settings with fbset:
it is the vga mode in /etc/lilo.conf which determines them.
The Xorg X11 X-windows server is the one recommended by Gentoo.
Select the usage of the framebuffer driver by editing /etc/X11/xorg.conf:
Section "Device"
Identifier "Card0"
Driver "fbdev"
Option "fbdev" "/dev/fb0"
VendorName "Unknown"
BoardName "Unknown"
EndSection
Section "Screen"
...
Device "Card0"
...
EndSection