Guido Guenther wrote: > > On Mon, Dec 11, 2000 at 12:28:19PM +0100, Maciej W. Rozycki wrote: > > friends) by glibc. At least XFree86 and SVGATextMode make use of these > > features. I suppose it's the same for MIPS (I haven't checked, though). > Yes. xf86MapVidMem & friends use /dev/mem to mmap videomemory & iospace > independent of architecure. > -- Guido I am surprised. I thought /dev/mem is for accessing SYSTEM RAM. (do a 'man' on /dev/mem) It is also confirmed by the code in drivers/char/mem.c. If you want to access anything beyond 'high_memory", nothing is read. Note that drivers/char/mem.c is cross-platform code. I am not sure how X would access video memory through /dev/mem on either MIPS or other platforms. That reason I want to fix /dev/kmem is that in some cases before a driver is written people want to play with the hardware directly from the userland (especially for demo purpose. :-0) Very useful for embedded systems. Potentially fixing /dev/mem can do the same job. However /dev/mem cannot differentiate cached or uncached accesses. With /dev/kmem, we just specify 0x8.. or 0xa.... Jun
