The vga=xxx boot code is used from the boot: prompt to force a video framebuffer mode. The Xfbdev X11 server can run on top of framebuffer modes. This is best done during the boot sequence by placing the Xfbdev extension in the directory from which extensions are automatically loaded (set using the tce=hdXY boot code). The system should be started in text mode initially as the .xsession file in /home/tc will need to be edited to start xfbdev instead of xvesa. A suitable form for this line is:
Xfbdev -mouse /dev/input/mice,5 -nolisten tcp -I &>/dev/null &'' (/dev/input/mice,5 should be replaced by whatever was originally in the command line for Xvesa in .xsession)
The desktop can then be started as usual with the command
Once .xsession has been edited & a backup performed the system can be booted straight to the desktop as the edited version of .xsession will be reloaded.
Further information on using the Linux framebuffer can be found in the Framebuffer HOWTO
Here is the table of all standard supported video modes. See below for how to access non-standard modes (e.g. 800×480).
|Standard Supported Video Modes|
|256 (8 bit)||769||771||773||775|
|32000 (15 bit)||784||787||790||793|
|65000 (16 bit)||785||788||791||794|
|16.7M (24 bit)||786||789||792||795|
In some cases the modes listed in the above table are not suitable. This may be because of
unusual display resolutions or just plain garbled displays (e.g. Toshiba Libretto 100CT/110CT). On these PC's there are additional modes available. These should be used get X to display correctly.
To use these 'extra' modes do the following:
1. Boot using the 'tinycore textmode' boot code at the 'boot:' prompt
2. Issue the command 'Xvesa -listmodes' (note the capital 'X'!)
3. Make a note of the mode(s) you need & the respective hex code(s) [See example below - hex code for mode is at start of mode line]
4. Add 0x200 to the hex code of the mode you want
5. Convert to decimal
6. Boot as normal (i.e. not 'tinycore textmode') using this number in the 'vga=xxx' boot code at the 'boot:' prompt, e.g. using 'tinycore vga=808' will get you to 800×480 16.7M colours on a Toshiba Libretto 100CT as in the example below.
For example, on a Toshiba Libretto 100CT:
'Xvesa -listmodes' gives a list of modes including:
0x0127: 800x480x16 TrueColor 5:6:5:0
0x0128: 800x480x24 TrueColor 8:8:8:0
To use the 24 bit 800×480 mode the correct number to use in the 'vga=xxx' boot code is:
0x0128 + 0x0200 = 0x0328 = 808 (decimal)
Note: It has been reported that some systems use a different offset to 0x200. This is not in compliance with the Framebuffer HOWTO.