Flushing of linux frame buffer issue on each write ?

[umanggupta]

I have a little query regarding the frame buffer initialization part
in X . Does X reset the /dev/fb0 [flush the buffer ] whenever it get
written by some process ??
If it is , then where it is done in xorg-X11 code ??.

After starting of X , I m using following line in one of my scripts to
redirect my img0 image to screen .
dd if=/etc/xdg/icons/img0 of=/dev/fb0

I m observing a <2 sec blank screen before img0 shown on screen
[written to /dev/fb0]

Even when my mouse cursor is shown on screen , before cursor comes up
, a 0.5 ms blank screen comes up .

Can I prevent my fb0 to get cleared before anydata get written onto
it ?? where should I look for this ?

In xorg.conf , I have :

Section "Device"
Identifier "fb0"
Driver "fbdev"
Option "fbdev" "/dev/fb0"
EndSection


Section "Screen"
Identifier "Screen 1"
Device "fb0"
EndSection


Any help would be appreciated.

[GNU-Fan]

Hello,

I don't know much specifics about the fbdev, but the location of the code you search would be distribution specific anyway. (Debian for example has most part of it in the xserver-xorg-video-fbdev package, which is the driver for the main xorg package.)
The upstream XOrg distributes everything in one big package but it is very hard work to get this compiled.


So my recommendation is to go ask on xorg Info Page.
You might meet the very persons who wrote the code in question there.
But keep in mind they are not Linux only, so mention it explicitly.