Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964973AbWLUO0V (ORCPT ); Thu, 21 Dec 2006 09:26:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965020AbWLUO0U (ORCPT ); Thu, 21 Dec 2006 09:26:20 -0500 Received: from e4.ny.us.ibm.com ([32.97.182.144]:54296 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964973AbWLUO0T (ORCPT ); Thu, 21 Dec 2006 09:26:19 -0500 Date: Thu, 21 Dec 2006 09:24:58 +0530 From: Vivek Goyal To: "Eric W. Biederman" Cc: Jean Delvare , Andi Kleen , LKML Subject: Re: Patch "i386: Relocatable kernel support" causes instant reboot Message-ID: <20061221035458.GE30299@in.ibm.com> Reply-To: vgoyal@in.ibm.com References: <20061220141808.e4b8c0ea.khali@linux-fr.org> <20061220214340.f6b037b1.khali@linux-fr.org> <20061221101240.f7e8f107.khali@linux-fr.org> <20061221102232.5a10bece.khali@linux-fr.org> <20061221010814.GA30299@in.ibm.com> <20061221022601.GB30299@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061221022601.GB30299@in.ibm.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1698 Lines: 44 On Thu, Dec 21, 2006 at 07:56:01AM +0530, Vivek Goyal wrote: [..] > > # Manual, Mixing 16-bit and 32-bit code, page 16-6) > > > > .byte 0x66, 0xea # prefix + jmpi-opcode > > -code32: .long 0x1000 # will be set to 0x100000 > > - # for big kernels > > +code32: .long startup_32 # will be set to %cs+startup_32 > > .word __BOOT_CS > > +.code32 > > +startup_32: > > + movl $(__BOOT_DS), %eax > > + movl %eax, %ds > > + movl %eax, %es > > + movl %eax, %fs > > + movl %eax, %gs > > + movl %eax, %ss > > + > > + xorl %eax, %eax > > +1: incl %eax # check that A20 really IS enabled > > + movl %eax, 0x00000000 # loop forever if it isn't > > + cmpl %eax, 0x00100000 > > + je 1b > > + > > + # Jump to the 32bit entry point > > + jmpl *(code32_start - start + (DELTA_INITSEG << 4))(%esi) > > Hi Eric, > > I got a basic query. Why have we introduced this additional jump to > startup_32 in the same file? Won't it work if we stick to old method of > enabling protected mode and then directly taking a jmp to startup_32 in > arch/i386/kernel/head.S. Am I missing something obivious? > Sorry, I meant arch/i386/boot/compressed/head.S and not arch/i386/kernel/head.S Thanks Vivek - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/