Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751736AbXICXU2 (ORCPT ); Mon, 3 Sep 2007 19:20:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750923AbXICXUV (ORCPT ); Mon, 3 Sep 2007 19:20:21 -0400 Received: from mail.tmr.com ([64.65.253.246]:39931 "EHLO gaimboi.tmr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750832AbXICXUU (ORCPT ); Mon, 3 Sep 2007 19:20:20 -0400 Message-ID: <46DC9700.7070208@tmr.com> Date: Mon, 03 Sep 2007 19:21:36 -0400 From: Bill Davidsen Organization: TMR Associates Inc, Schenectady NY User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.8) Gecko/20061105 SeaMonkey/1.0.6 MIME-Version: 1.0 To: Xu Yang CC: LKML Subject: Re: ramdisk References: <46DC2228.7080503@tmr.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4072 Lines: 127 Xu Yang wrote: > thanks for the reply. > > no , it is not decompressed. isn' t the kernel supposed to do that? As > we have tried to load this filesystem on the pc, it turns out the the > kernel can recognize it. > > concerning the root=/dev/ram0, > as the default value is root=/dev/nfs, so I just modify the nfs to > ram0. is this might be a problem? > > Hopefully someone who works with this regularly can provide some answers, the only time I used booting into a RAM-only system the tools which I had "just worked" and I followed the steps outlined without fully understanding the details. However, I just tried loop mounting a compressed filesystem and that didn't work, while decompressing into a ramdisk and mounting worked fine. That's why I asked if your tool was just copying to RAM without decompression, since I have no ides what tool you use. As for the name, your original post used "dev" without a leading "/" and while I assumed it was a typo, I thought it was worth mentioning since you were looking for suggestions. I would expect /dev/ram0 to be correct. I would try the decompressed image next, and I have no other ideas at the moment. > regards, > > > 2007/9/3, Bill Davidsen : > >> Xu Yang wrote: >> >>> Hi everyone, >>> >>> I want to use ramdisk to boot my filesystem, as I can't use NFS and harddisk. >>> >>> I have load the ramdisk into the ram memory (start address :0x4000000) >>> >>> and in the boot options I specified : root =dev/ram0 initrd=0x4000000 >>> >>> but the kernel said it can not find any file system on it. >>> >>> >> Looking at the information below, did the program which loaded the >> filesystem into RAM decompress it? It noted that it was compressed so I >> would assume so, but I am unfamiliar with ARM tools, so I ask the >> question. Also, should the boot device be "/dev/ram0" rather than >> "dev/ram0" or is that correct for your system? >> >> >>> Here is the information I can supply : >>> U-Boot 1.2.0 (Aug 31 2007 - 20:54:55) >>> >>> *** Auto-detects ethernet chip *** >>> >>> >>> >>> DRAM: 0 kB >>> ## Unknown FLASH on Bank 1 - Size = 0x00000000 = 0 MB >>> Flash: 0 kB >>> *** Warning - bad CRC, using default environment >>> >>> In: serial >>> Out: serial >>> Err: serial >>> >>> Hit any key to stop autoboot: 0 >>> ## Booting image at 00007fc0 ... >>> Image Name: Linux-2.6.19-arm2 >>> Image Type: ARM Linux Kernel Image (uncompressed) >>> Data Size: 740372 Bytes = 723 kB >>> Load Address: 00008000 >>> Entry Point: 00008000 >>> OK >>> >>> >>> ## Loading Ramdisk Image at 04000000 ... >>> Image Name: ramdisc >>> Image Type: ARM Linux RAMDisk Image (gzip compressed) >>> Data Size: 12582962 Bytes = 12 MB >>> Load Address: 04000000 >>> Entry Point: 04000000 >>> >>> Starting kernel ... >>> >>> >>> ......................................................................................... >>> >>> RAMDISK driver initialized: 16 RAM disks of 10240K size 1024 blocksize >>> <6>loop: loaded (max 8 devices) >>> <6>mice: PS/2 mouse device common for all mice >>> <6>VFP support v0.3: implementor 41 architecture 1 part 20 variant b rev 3 >>> No filesystem could mount root, tried: ext2 cramfs vfat >>> <0>Kernel panic - not syncing: VFS: Unable to mount root fs on >>> unknown-block(1,0) >>> >>> >>> Who can give me some hints ? or point me some direction to handle this. >>> >>> I appreciate this very much. >>> >>> regards, >>> >>> Yang >>> >> -- >> Bill Davidsen >> "We have more to fear from the bungling of the incompetent than from >> the machinations of the wicked." - from Slashdot >> >> > > -- bill davidsen CTO TMR Associates, Inc Doing interesting things with small computers since 1979 - 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/