[Libdlo] Draw fbX number on the green screen

Alexander Todorov atodorov at otb.bg
Mon Nov 8 11:41:41 PST 2010


On 8.11.2010 21:17, Bernie Thompson wrote:
>
> Very cool!  Something to think about:  Hardcoding that font data, etc.
> probably won't be accepted back into the Linux kernel tree, but do you
> think it would be possible to do this from user mode as a udev rule?
> A small program to scribble on /dev/fbX when that device arrives?
>


Hmm, haven't thought about that since my knowledge about fbdev drivers is 
limited. If you can give me some directions I'll poke around in the code:

1) The user space program will write to a file under /sys I guess. What is it 
supposed to write ? A blob with the device number doesn't seem better than an 
array with the same data in the code. It's just not in the kernel.

2) Are there any functions for drawing text/shapes on the DisplayLink device or 
other fbdev devices? I can use primitive functions and draw the characters out 
of individual components.

3) Any other way of identifying the device/display (i.e. draw 3 circles for the 
3rd device) is also welcome if it's short to implement and is easily 
recognizable by humans.

Thanks,
Alexander.


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