cvs commit: src/sys/boot/i386/mbr Makefile mbr.s
yar at FreeBSD.org
Mon Aug 30 22:08:59 PDT 2004
On Mon, Aug 30, 2004 at 11:41:00AM -0400, John Baldwin wrote:
> On Saturday 28 August 2004 04:39 am, Yar Tikhiy wrote:
> > yar 2004-08-28 08:39:35 UTC
> > FreeBSD src repository
> > Modified files:
> > sys/boot/i386/mbr Makefile mbr.s
> > Log:
> > Don't be too smart, just try packet mode of INT13 first.
> > This way of operation is more robust than the "AI" used
> > before.
> > Add flags to mbr accessible from make.conf as BOOT_MBR_FLAGS.
> > Only one flag is defined now, "allow using packet mode", which
> > is 0x80 in accord with the rest of i386 boot code. The "packet"
> > flag is on by default.
> > PR: i386/70241
> > Submitted by: Valentin Nechayev <netch <@> netch.kiev.ua> (inital
> > version) Discussed with: jhb (by Valentin Nechayev)
> > Tested on: bochs (with EDD turned on or off by patching the BIOS),
> > PCs
> > Revision Changes Path
> > 1.14 +4 -0 src/sys/boot/i386/mbr/Makefile
> > 1.7 +6 -6 src/sys/boot/i386/mbr/mbr.s
> Hmm, there are no e-mails from me in the PR trail and I don't recall ever be
> in favor of these changes (though I don't care enough to ask for them to be
> backed out.. Only really old machines with pre-1995 BIOS should be broken in
> theory.) It would be nice if you wouldn't claim that I supported something
> that I didn't actually support though.
John, I try to believe people as much as possible since that saves
my time, and I believe Valentin Nechayev particularly because I know
him quite well. Here are his words straight from the PR:
Revert logic of selection between traditional and EDD reading mode
to one which prefers EDD if available (as was in the same file in revisions
1.11 and 1.12). This is supported by John Baldwin (private conversation
after thread in hackers@):
The problem is that there are BIOS's out there that claim to support EDD but
still don't work correctly. I don't remember all the details at this point,
but I think it had to do with sysinstall not always being in sync with the
BIOS about how sectors were in a cylinder. I guess though we could just turn
EDD on by default in 5.x or perhaps 6.0. 5.x doesn't really run well on a
386 or even a 486, and that is the class of machine that has problems with
I know it could be hard on memory to return to issues one used to
work at in the past, so I decided not to bother you to confirm if
that quote is actually yours. Please excuse me if it was a poor
idea of mine.
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