From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: Extboot Option ROM rewritten in C - v3 Date: Fri, 18 Apr 2008 08:19:08 -0500 Message-ID: <48089FCC.6030006@us.ibm.com> References: <9cde8bff0804161830j74ad21f9r7fb1bc5b1e7ab28e@mail.gmail.com> <4806E77D.7070100@zytor.com> <9cde8bff0804180400p73d268e4y34ba48d3c2b6d533@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel@lists.sourceforge.net, "H. Peter Anvin" To: Nguyen Anh Quynh Return-path: In-Reply-To: <9cde8bff0804180400p73d268e4y34ba48d3c2b6d533@mail.gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org Nguyen Anh Quynh wrote: > On Thu, Apr 17, 2008 at 3:00 PM, H. Peter Anvin wrote: > >>> + .globl linux_boot >>> +linux_boot: >>> + cli >>> + cld >>> + mov $0x9000, %ax >>> + mov %ax, %ds >>> + mov %ax, %es >>> + mov %ax, %fs >>> + mov %ax, %gs >>> + mov %ax, %ss >>> + mov $0x8ffe, %sp >>> + ljmp $0x9000 + 0x20, $0 >>> >>> >> The hard use of segment 9000 is really highly unfortunate for bzImage, >> since it restricts its heap more than necessary. I suggest following the >> patterns used by the (new) Qemu loader. >> > > Actually, this code is left from the original code of Anthony, and it > seems he took it from qemu 0.8 version. > > Anthony, may you explain why you want to hijact the linux boot process > here? If I understand correctly, we can just let the original int19 > execute, and if linux boot is desired, it would work in normal way. So > why you want to do this? > The thinking is to eliminate the need to hijack the boot sector when using the -kernel option. However, the linux boot stuff in extboot has been broken since hpa rewrote the boot code. It can be removed for now and I'll eventually revisit it. Regards, Anthony Liguori > Thanks, > Q > ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone