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Re: Frame buffer use on Coldfire problem

On Wed, 19 Dec 2007, jkimble@one.net wrote:
> I'm running a 2.6.10 kernel on a Coldfire (M5484) and I'm trying to
> get some frame buffer graphics going. The video chip I'm using is a
> Epson S1D13a04 and there was actually a driver for Linux kernel 2.6.8
> from Epson that I was able to port to my kernel. Thought life was good
> but I have yet to get anything on the screen at all. My first attempt
> is listed below. The problem occurs on the memory map (mmap) command.
> Thought the /dev/fb0 device opens and the call to ioctl returns valid
> information, when I call mmap to set up the memory the call fails
> (returns -1). The device resides at physical address 0x44040000.

>     screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;
>     fbp = mmap((caddr_t)0, screensize, PROT_READ|PROT_WRITE, MAP_SHARED,
> fbfd, 0);

I guess it fails because screensize is not a multiple of the page size?

For testing frame buffer devices, you can always try fbtest (CVS module
FBdev/utlilities/fbtest (yes, spelling typo in the path name ;-) from
project linux-fbdev.sf.net, cfr.



Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

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