Re: Gives Bus error in memcpy() in coping /dev/fb0 to a file.

["Antonino A. Daplas" <adaplas@gmail.com>]

On Wed, 2007-03-07 at 17:20 +0530, Vishal Soni wrote:
> hello,
> 
> I am trying to get the snapshot of the screen through a c program by mmaping
> the framebuffer device /dev/fb0 .
> For this i compiled kernel with virtual framebuffer support and passing
> vga=791 as boot line argument.
> 
> Though i am able to get snapshot by
> [root@tw pcapp]# cat /dev/fb0 > frame
> 
> and see it on the screen by
> [root@tw pcapp]# cat frame > /dev/fb0
> 
> But when i try to capture the frame buffer using the below c code, It gives
> bus error @ memcpy()
> 
> Output :::::::::
> 
> [root@tw pcapp]# ./pcapp
> 1024x768, 16bpp
> framebuffer device mapped to memory @ 0xb7db3000.
> FB_FRAME mapped to memory @ 0xb7c33000.
> Bus error

I don't think vfb's framebuffer can be mmapped.  It's fixable, but
nobody seems to have a need for it,  yet.

Tony



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