From owner-freebsd-bugs Tue Sep 9 10:00:07 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id KAA20350 for bugs-outgoing; Tue, 9 Sep 1997 10:00:07 -0700 (PDT) Received: (from gnats@localhost) by hub.freebsd.org (8.8.7/8.8.7) id KAA20310; Tue, 9 Sep 1997 10:00:01 -0700 (PDT) Date: Tue, 9 Sep 1997 10:00:01 -0700 (PDT) Message-Id: <199709091700.KAA20310@hub.freebsd.org> To: freebsd-bugs Cc: From: Tor Egge Subject: Re: kern/4486: ahc(4) in RELENG_2_2 can't do kernel core dumps Reply-To: Tor Egge Sender: owner-freebsd-bugs@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk The following reply was made to PR kern/4486; it has been noted by GNATS. From: Tor Egge To: j@uriah.heep.sax.de Cc: FreeBSD-gnats-submit@FreeBSD.ORG Subject: Re: kern/4486: ahc(4) in RELENG_2_2 can't do kernel core dumps Date: Tue, 09 Sep 1997 18:50:44 +0200 Some S3 cards does not like accesses to the monocrome video memory address region (starting at memory address 0xb8000), and the memory dump hangs when dumping that region. With the following ugly hack/workaround, and defining SDDUMP_HANGS as an option in the kernel config file, the kernel will probably be able to perform a core dump. Index: sd.c =================================================================== RCS file: /home/ncvs/src/sys/scsi/sd.c,v retrieving revision 1.95.2.3 diff -c -r1.95.2.3 sd.c *** sd.c 1997/08/11 02:04:09 1.95.2.3 --- sd.c 1997/08/27 16:57:47 *************** *** 932,937 **** --- 932,944 ---- blknum = dumplo + blkoff; while (num > 0) { + #if defined(SDDUMP_HANGS) && defined(__i386__) + if ((vm_offset_t) addr>=0xa0000 && + (vm_offset_t) addr < 0x100000) + pmap_enter(kernel_pmap, (vm_offset_t)CADDR1, trunc_page(0), + VM_PROT_READ, TRUE); + else + #endif pmap_enter(kernel_pmap, (vm_offset_t)CADDR1, trunc_page(addr), VM_PROT_READ, TRUE); /*