From: Christian Groessler (cpg@aladdin.de)
Date: Wed 06 Jan 1999 - 00:00:58 IST
Hi, On 22/12/98 21:47:14 Matan Ziv-Av wrote: > >I'm trying to change svgalib, so that /dev/mem can be closed at the >same time that root privileges are given up. Good idea! >The way I did it (that requires changing the drivers) is mmapping the >64k buffer at a0000 and the linear frame buffer in vga_init, and then, >wherever there was an mmap of /dev/mem, I substituted one of the >pointers. So every driver must be changed to get these things at vga_init() time :-( But it seems to be needed to fix the problem. >This works great for banked memory access (zgv, quake2). >The problem is that testlinear fails with a SegFault. I tried a >simpler program that uses linear, and found out that if I use the >exact mmap in my program, It worked, i.e. >vbuf=mmap(...); works, while >vbuf=LINEAR_POINTER; fails. What is LINEAR_POINTER? The virtual address of the linear buffer mapped at vga_init() time? >If anyone can tell me the reason, or has another idea for closing >/dev/mem at initialization time, I'd like to hear it. No idea, but a question: -) Is this modified (test-) version available. I would like to check it out, too. regards, chris
This archive was generated by hypermail 2.1.4 : Wed 21 Jan 2004 - 22:10:22 IST