Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965199AbWLUKdi (ORCPT ); Thu, 21 Dec 2006 05:33:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965195AbWLUKdi (ORCPT ); Thu, 21 Dec 2006 05:33:38 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:40560 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965199AbWLUKdh (ORCPT ); Thu, 21 Dec 2006 05:33:37 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Jean Delvare Cc: Vivek Goyal , Andi Kleen , LKML Subject: Re: Patch "i386: Relocatable kernel support" causes instant reboot 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> Date: Thu, 21 Dec 2006 03:32:33 -0700 In-Reply-To: <20061221102232.5a10bece.khali@linux-fr.org> (Jean Delvare's message of "Thu, 21 Dec 2006 10:22:32 +0100") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2790 Lines: 83 Jean Delvare writes: > On Thu, 21 Dec 2006 10:12:40 +0100, Jean Delvare wrote: >> On Wed, 20 Dec 2006 15:22:20 -0700, Eric W. Biederman wrote: >> > Ok. Here is a small diff that inserts the infinite loops, between >> > each section of code in head.S Procedurally please trying booting >> > this unmodified and see if it boots, then remove the infinite loop >> > until you come to the one where the system reboots instead of hangs. >> > >> > That should at least give me a good idea of where to look. >> > If 20 hangs and 21 still reboots we are into misc.c and the >> > decompressor. And I will have to ask something different. >> >> OK, I'll start the tests now, I'll let you know the outcome when I'm >> done. > > Hm, that was quick... Even with your unmodified patch, the machine > still reboots. Does that make any sense to you? > > I can try installing a more recent system on the same hardware if it > helps. Grr. I guessed the problem was to late in the game it seems the problem is in setup.S Before we switch to 32bit mode. Ok. There is almost enough for inference but here is a patch of stops for setup.S let's see if one of those will stop the reboots. I have a strong feeling that we are going to find a tool chain issue, but I'd like to find where we ware having problems before we declare that to be the case. Eric diff --git a/arch/i386/boot/setup.S b/arch/i386/boot/setup.S index 06edf1c..2868020 100644 --- a/arch/i386/boot/setup.S +++ b/arch/i386/boot/setup.S @@ -795,6 +795,7 @@ a20_done: #endif /* CONFIG_X86_VOYAGER */ # set up gdt and idt and 32bit start address +10: jmp 10b lidt idt_48 # load idt with 0,0 xorl %eax, %eax # Compute gdt_base movw %ds, %ax # (Convert %ds:gdt to a linear ptr) @@ -846,6 +847,7 @@ flush_instr: subw $DELTA_INITSEG, %si shll $4, %esi # Convert to 32-bit pointer +11: jmp 11b # jump to startup_32 in arch/i386/boot/compressed/head.S # # NOTE: For high loaded big kernels we need a @@ -862,6 +864,7 @@ code32: .long startup_32 # will be set to %cs+startup_32 .word __BOOT_CS .code32 startup_32: +12: jmp 12b movl $(__BOOT_DS), %eax movl %eax, %ds movl %eax, %es @@ -869,12 +872,14 @@ startup_32: movl %eax, %gs movl %eax, %ss +13: jmp 13b 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 +14: jmp 14b # Jump to the 32bit entry point jmpl *(code32_start - start + (DELTA_INITSEG << 4))(%esi) .code16 - 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/