Date: Sat, 9 Nov 2002 13:41:41 -0800 From: David Schultz <dschultz@uclink.Berkeley.EDU> To: Mitsuru IWASAKI <iwasaki@jp.FreeBSD.org> Cc: gallatin@cs.duke.edu, petry@NetMasters.Com, julian@elischer.org, sidcarter@symonds.net, current@FreeBSD.ORG Subject: Re: Kernel not booting....Immediate crash Message-ID: <20021109214141.GA8555@HAL9000.homeunix.com> In-Reply-To: <20021108.135430.68032362.iwasaki@jp.FreeBSD.org> References: <Pine.BSF.4.21.0211071023530.5860-100000@InterJet.elischer.org> <200211071859.gA7IxbEV075350@netwolf.NetMasters.Com> <15818.50698.91676.542116@grasshopper.cs.duke.edu> <20021108.135430.68032362.iwasaki@jp.FreeBSD.org>
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Thus spake Mitsuru IWASAKI <iwasaki@jp.FreeBSD.org>: > Hmmm, I didn't notice that there is a BIOS which requires > memory area below 640K even when calling INT 15H/E820. > > We cannot trust that today's BOISes have INT 12H, so it's > difficult to determine base memory size w/o INT 15H/E820. You keep saying this, which really surprises me, because the int 12h interface has been standard for over two decades. I have not heard any great clammoring that DOS and NetBSD fail to boot on modern machines, and yet they both use int 12h. Are you *sure* int 12h is really broken, or do you think perhaps the breakage you're seeing is a side-effect of another bug? Does int 12h work in real mode? Exactly what hardware has this problem? Also, you mentioneded earlier that Linux doesn't use int 12h anymore. But notice that they call 15:E820 in real mode, rather than turning on virtual memory and then temporarily mapping an arbitrary chunk of the first 640K of RAM. Why don't you just put the memory size detection code in locore.s? I'd be happy to help out with this, although my time is constrained after Monday. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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