Date: Sun, 27 Apr 2003 08:04:35 +1000 (EST) From: Andy Farkas <andyf@speednet.com.au> To: Ruslan Ermilov <ru@freebsd.org> Cc: current@freebsd.org Subject: Re: i386/loader compiled with NOFORTH Message-ID: <20030427075835.Q42886-100000@hewey.af.speednet.com.au> In-Reply-To: <20030426204542.GD66677@sunbay.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sat, 26 Apr 2003, Ruslan Ermilov wrote: > On Fri, Apr 25, 2003 at 02:46:26PM -0700, Terry Lambert wrote: > > John Baldwin wrote: > > > > > > > > John, is there a way to fix btx/loader/whatever so that > > > > heap memory is not limited to 640K? > > > > > > Not really. At least, not easily. We load the kernel up above 1mb, > > > but we don't know how much memory lives up above 1mb and we assume > > > that there is enough for the kernel and that's it. > > > > You are limited to what you can access in real mode, without > > Gate A20 (16M, at which point the address space wraps). > > > Shhh, don't tell this anyone! ;-) > > A20 (21th address line) allows one to access up to ffff:ffff > byte, that is (1M + 64K - 16) bytes of memory. Actually, you can access the entire 4GB of memory in "unreal" mode. <http://x86.ddj.com/ddj/aug98/aug98.htm>; -- :{ andyf@speednet.com.au Andy Farkas System Administrator Speednet Communications http://www.speednet.com.au/
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030427075835.Q42886-100000>