Flushing of /dev/fb0 in X before gets overwritten ??

umang gupta umang.ece at gmail.com
Mon May 4 06:23:22 PDT 2009


Hi All ,

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 .



Umang


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