From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pa0-f53.google.com ([209.85.220.53]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UP0ZQ-00050O-8s for kexec@lists.infradead.org; Mon, 08 Apr 2013 01:08:28 +0000 Received: by mail-pa0-f53.google.com with SMTP id bh4so2951535pad.40 for ; Sun, 07 Apr 2013 18:08:25 -0700 (PDT) Date: Mon, 8 Apr 2013 09:08:04 +0800 From: Wang YanQing Subject: Re: [PATCH] i386:kexec-bzImage: Use "\0" as command line instead of empty command line Message-ID: <20130408010804.GA2241@udknight> References: <20130403094356.GA7259@udknight> <515FB809.3020103@gmail.com> <20130407010103.GA2176@udknight> <51610A32.6080200@cn.fujitsu.com> <20130407093540.GA4046@udknight> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20130407093540.GA4046@udknight> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: Zhang Yanfei Cc: jbarnes@sgi.com, tjd21@cl.cam.ac.uk, khalid.aziz@hp.com, kexec@lists.infradead.org, horms@verge.net.au, ebiederm@xmission.com, hari@in.ibm.com, Zhang Yanfei On Sun, Apr 07, 2013 at 05:35:40PM +0800, Wang YanQing wrote: > On Sun, Apr 07, 2013 at 01:54:58PM +0800, Zhang Yanfei wrote: > > With no commandline, can the new kernel boot? > > I tried in my box and the new kernel just panicked for it cannot > > find a root= argument in its commandline. > I am sure the kernel boot, > rootfs_initcall(populate_rootfs) in initramfs.c > well populate the root fs, and there is a /init > in initramfs, this /init will mount the really > root device, and the system is running. Your kernel panic, because the below line in init/main.c failed: if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) kernel then run into prepare_namespace, but prepare_namespace failed too, then the kernel panic. I don't know why, but if rootfs_initcall(populate_rootfs) works ok, kernel don't need to call prepare_namespace, because the decompressed initramfs will become the root fs and sys_access will success. Sorry for I forget to mention my test kernel is v3.8.6, but if my memory don't lie me, I can boot v2.6.32 without a root= parameter, we had use v2.6.32 as product kernel still more than one year two years ago. Thanks _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec