From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <7b2d0cba0ec72119063d975d74e0ddae@plan9.bell-labs.com> To: 9fans@cse.psu.edu Subject: Re: [9fans] /sys/src/^(9 boot)^/pc/memory.c From: David Gordon Hogan MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 17 Sep 2002 18:04:56 -0400 Topicbox-Message-UUID: ed532b52-eaca-11e9-9e20-41e7f4b1d025 > Oops. I did not combine using the wavelan and trying > to use the i81x driver. If I do have a wavelan in the > pcmcia slot and I let aux/vga be run (trying i81x on > thinkpad R31, mouseport ps2, vgasize 640x480x8, monitor xga) > I get: > > panic: mmuwalk2: va 80526000 entry 4001E3 The i81x driver uses mmuwalk() to get the PTE of a single page that it allocates for the hardware cursor. It needs this to mark the memory as uncached, otherwise the hardware cursor won't update correctly. Unfortunately, this strategy only works if the cursor is allocated in the first 4M of memory. After that, it isn't possible to single out an individual page in the kernel virtual mapping. Hence the panic. I'm not sure how to fix this. It might be neccesary to change the page table to make the appropriate 4M region use a level 2 page table.