Subject: Re: Unable to mmap /dev/mem
To: Jared D. McNeill <email@example.com>
From: Matthieu Herrb <firstname.lastname@example.org>
Date: 11/13/2000 16:57:40
You wrote (in your message from Monday 13)
> On Mon, 13 Nov 2000, Matthieu Herrb wrote:
> > You should try to use ktrace on the applications in question, if you
> > haven't already done it.
> Here are the last 40 lines of the ktrace when run as root. Hope this is
> 4054 snes9x CALL mmap(0,0x800000,0x1,0x1,0,0,0xcd000000,0xffffffff)
> 4054 snes9x RET mmap -1 errno 22 Invalid argument
Yes. It's trying to mmap the framebuffer, which has a physical address
that is above the top of the RAM. /dev/mem doesn't allow this.
In this case you need to use the aperture driver and to patch the
application to try /dev/xf86 if /dev/mem fails.
The aperture driver will allow mmaping of any address above the end of
physical memory or in the BIOS VGA range.