Date: Tue, 11 Apr 2006 07:34:39 -0700 From: Maxim Sobolev <sobomax@FreeBSD.org> To: John Baldwin <jhb@FreeBSD.org> Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/boot/i386/cdboot cdboot.s Message-ID: <443BBE7F.6060906@FreeBSD.org> In-Reply-To: <200604110818.20705.jhb@freebsd.org> References: <200604110439.k3B4dTOD072774@repoman.freebsd.org> <200604110818.20705.jhb@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
boo1 does the same - timeout loop. My small research seemingly suggests that doing A20 via the BIOS is not very reliable and may not work on all machines. -Maxim John Baldwin wrote: > On Tuesday 11 April 2006 12:39 am, Maxim Sobolev wrote: >> sobomax 2006-04-11 04:39:29 UTC >> >> FreeBSD src repository >> >> Modified files: >> sys/boot/i386/cdboot cdboot.s >> Log: >> When enabling A20 put upper limit on amount of time we wait for the >> keyboard controller to get ready (65K x ISA access time, visually around 1 >> second). If we have wait more than that amount it's likely that the >> hardware is a legacy-free one and simply doesn't have keyboard controller >> and doesn't require enabling A20 at all. >> >> This makes cdboot working for MacBook Pro with Boot Camp. > > You'll probably need to do the same for boot1 and I think BTX. > Alternatively, you should see how the loader is handling A20 and > do that in the various boot programs instead (I think there's a PR > somewhere about using a BIOS call instead of frobbing the keyboard > controller directly that supposedly fixes things like USB keyboards > in the loader.) >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?443BBE7F.6060906>