VFS: Cannot open root device ...
I'm trying to port a 2.6 kernel to a V2Pro-based board that I've got. I get the following output when trying to boot: RAMDISK: Compressed image found at block 0 VFS: Mounted root (ext2 filesystem). VFS: Cannot open root device NULL or unknown-block(0,0) Please append a correct root= boot option Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) I'm trying to use an initrd RAMDISK, and I've made sure that RAMDISK and initrd support are both enabled in the kernel configuration. Any ideas would be appreciated. Cheers, Chris Dumoulin -- *--Christopher Dumoulin--* Software Team Leader http://ics-ltd.com/ http://ics-ltd.com/ Interactive Circuits and Systems Ltd. 5430 Canotek Road Ottawa, ON K1J 9G2 (613)749-9241 1-800-267-9794 (USA only) This e-mail is private and confidential and is for the addressee only. If misdirected, please notify us by telephone and confirm that it has been deleted from your system and any hard copies destroyed. You are strictly prohibited from using, printing, distributing or disseminating it or any information contained in it save to the intended recipient.
VFS: Cannot open root device ...
On 6/8/06, Chris Dumoulin cdumoulin at ics-ltd.com wrote: I'm trying to port a 2.6 kernel to a V2Pro-based board that I've got. I get the following output when trying to boot: RAMDISK: Compressed image found at block 0 VFS: Mounted root (ext2 filesystem). VFS: Cannot open root device NULL or unknown-block(0,0) Please append a correct root= boot option Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) What boot loader are you using? In the boot loader where does it think the root fs is located? My guess is /dev/ram0 or something like that? So I'd check your ramdisk to see that it has a /dev/ram0. Make sure you have rights to it. -stv I'm trying to use an initrd RAMDISK, and I've made sure that RAMDISK and initrd support are both enabled in the kernel configuration. Any ideas would be appreciated. Cheers, Chris Dumoulin -- *--Christopher Dumoulin--* Software Team Leader http://ics-ltd.com/ http://ics-ltd.com/ Interactive Circuits and Systems Ltd. 5430 Canotek Road Ottawa, ON K1J 9G2 (613)749-9241 1-800-267-9794 (USA only) This e-mail is private and confidential and is for the addressee only. If misdirected, please notify us by telephone and confirm that it has been deleted from your system and any hard copies destroyed. You are strictly prohibited from using, printing, distributing or disseminating it or any information contained in it save to the intended recipient. ___ Linuxppc-embedded mailing list Linuxppc-embedded at ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded
VFS: Cannot open root device 31:03 or unknown-block(31,3)
On Friday 06 January 2006 16:08, Wolfgang Denk wrote: This is a serious misunderstanding. There is no such thing like a specific kernel version which is supported by the ELDK. True, but not entirely. ELDK-3.1.1 has a glibc compiled with support of a certain version of the kernel (I guess it's 2.4.xx), so newer kernels might run (because they are obviously backwards compatible), but some features of 2.6 cannot be used (e.g. support for the latest syscalls, different HZ, etc...) A second issue is the boot procedure. If you are a beginner with linux, you'd probably start booting from NFS root as it gets installed in the ELDK/ppc_xxx directory. That probably won't work very well with latest 2.6 kernels (device files missing, sysfs not mounted, shmfs has different name, etc...) A third issue is the compiler issue. Some newer kernels might not compile correctly anymore with older compilers. These three things are what I meant with supported or not supported. The ELDK is primarily a *toolkit* which works with arbitrary C and C++ programs and with any version of the kernel tree (at least in theory; very recent version s of the Linux kernel [ 2.6.14] cannot be compiled with ELDK 3.1.x any more, but this is a different issue). See what I mean? HappyPhot did just that: compile 2.6.14.2 with ELDK 3.1.1!!! Do you know where to get the infomation about which kernel version it supports? The ELDK supports *any* kernel version. Ok, let's talk about recommended kernel then. I would never recommend someone unexperienced to start with a combination of ELDK-3.1.1 and kernel 2.6.xx. The one that comes with that version of ELDK? Just a guess ;-) Wrong guess. But it'd still be the one with most chances of success unless there are known problems with that kernel on a Sandpoint board. Greetings, -- David Jander Protonic Holland.
VFS: Cannot open root device 31:03 or unknown-block(31,3)
In message 200601090945.22564.david.jander at protonic.nl you wrote: ELDK-3.1.1 has a glibc compiled with support of a certain version of the kernel (I guess it's 2.4.xx), so newer kernels might run (because they are They do run. obviously backwards compatible), but some features of 2.6 cannot be used (e.g. support for the latest syscalls, different HZ, etc...) You can also change HZ if you like. A second issue is the boot procedure. If you are a beginner with linux, you'd probably start booting from NFS root as it gets installed in the ELDK/ppc_xxx directory. That probably won't work very well with latest 2.6 kernels (device files missing, sysfs not mounted, shmfs has different name, etc...) You can (mis-) configre a 2.4 kernel too. Using a sane kernel configuration ther ewill be no problems. We have been using ELDK 3.1.1 for a long time ourself developing 2.6 kernel code. C++ programs and with any version of the kernel tree (at least in theory; very recent version s of the Linux kernel [ 2.6.14] cannot be compiled with ELDK 3.1.x any more, but this is a different issue). See what I mean? HappyPhot did just that: compile 2.6.14.2 with ELDK 3.1.1!!! I wrote 2.6.14; 2.6.14.2 is just a branch off 2.6.14 and is fine AFAICT. The ELDK supports *any* kernel version. Ok, let's talk about recommended kernel then. I would never recommend There is no recommended kernel version. On contrary, we take great efforts to keep the ELDK independent of speicfic kernelk versions as far as possible. Best regards, Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de Quantum particles: The dreams that stuff is made of.
VFS: Cannot open root device 31:03 or unknown-block(31,3)
in your .config: CONFIG_JFFS2_FS=m This is wrong. You have to choose y, not m (for module). This way jffs2 is compiled as a module. That means, that jffs2 filesystem will not be available until the module is loaded with insmod jffs2 of something similar. That in turn means that your system has to start up first in order to be able to do this, but since you can't start because your root filesystem is on jffs2, you have created yourself a chicken and egg problem. If you choose y then jffs2 support will be compiled into the kernel, and thus be available before booting. Hi, David, Yes, you are right. After changing it to 'y', the VFS: Cannot open root... message was gone. I'm so happy and thank you very much. Now it is another problem again. (something like: Oops: kernel access of bad area. sig:11...). I am going to check what happened. In your bootlog: Linux version 2.6.14.2 (happy at sddlinux1) (gcc version 3.3.3 (DENX ELDK 3.1.1 3.3.3-10)) #29 Sun Jan 1 22:34:28 CST 2006 Motorola SPS Sandpoint Test Platform I see you are using DENX ELDK 3.1.1 and a kernel which AFAIK is not supported by this version of ELDK. Are you sure this is supposed to work? It probably will, but I don't know what the Sandpoint is (it looks like a PowerPC processor of the MPC7xx series to me), so I couldn't tell. Do you know where to get the infomation about which kernel version it supports? thank you, /HappyPhot
VFS: Cannot open root device 31:03 or unknown-block(31,3)
On Friday 06 January 2006 15:09, HappyPhot wrote: I see you are using DENX ELDK 3.1.1 and a kernel which AFAIK is not supported by this version of ELDK. Are you sure this is supposed to work? It probably will, but I don't know what the Sandpoint is (it looks like a PowerPC processor of the MPC7xx series to me), so I couldn't tell. Do you know where to get the infomation about which kernel version it supports? The one that comes with that version of ELDK? Just a guess ;-) Greetings, -- David Jander
VFS: Cannot open root device 31:03 or unknown-block(31,3)
In message 200601061519.14550.david.jander at protonic.nl you wrote: I see you are using DENX ELDK 3.1.1 and a kernel which AFAIK is not supported This is a serious misunderstanding. There is no such thing like a specific kernel version which is supported by the ELDK. You don't talk about any specific version of a C programm that is supported by the GNU compiler either. The ELDK is primarily a *toolkit* which works with arbitrary C and C++ programs and with any version of the kernel tree (at least in theory; very recent version s of the Linux kernel [ 2.6.14] cannot be compiled with ELDK 3.1.x any more, but this is a different issue). Do you know where to get the infomation about which kernel version it supports? The ELDK supports *any* kernel version. The one that comes with that version of ELDK? Just a guess ;-) Wrong guess. Best regards, Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de I've seen it. It's rubbish. - Marvin the Paranoid Android
VFS: Cannot open root device 31:03 or unknown-block(31,3)
On Monday 02 January 2006 15:48, HappyPhot wrote: Hi, I've suffered for many days and google almost every where. I would like to boot from the flash with jffs2 (i.e. using jffs2 as my root /) . But it alyaws shows: VFS: Cannot open root device. (whole message is as below) Anybody knows what may cause this ? Please help and thank you. [...] You omitted the interesting part of the log output, the bootarguments at the very beginning. What is the value of root= ? Maybe you made the typical mistake of specifying /dev/mtd3 instead of /dev/mtdblock3, or you didn't compile in support for mtd access as a block device? Hi, David and all, I've tried root=/dev/mtdblock3, root=/dev/mtd3, root=31:03 etc. And Caching block device access to MTD devices was also selected when 'make menuconfig'. The results were the same. I use phys_mapped_flash and mtdparts=phys_mapped_flash:2M(k4),2M(k6), 4M(rd),4M(jffs2),-(User_Data). What is the root= I should use ? Also, I am wondering how the kernel knows /dev/mtdblock3 is in my flash ? I think I never do any setting about this thank you , /HappyPhot
VFS: Cannot open root device 31:03 or unknown-block(31,3)
Hi, I've suffered for many days and google almost every where. I would like to boot from the flash with jffs2 (i.e. using jffs2 as my root /) . But it alyaws shows: VFS: Cannot open root device. (whole message is as below) Anybody knows what may cause this ? Please help and thank you. /HappyPhot ==(booting message)== ... physmap flash device: 100 at 7000 phys_mapped_flash: Found 2 x8 devices at 0x0 in 16-bit bank Intel/Sharp Extended Query Table at 0x0031 Using buffer write method cfi_cmdset_0001: Erase suspend on write enabled 5 cmdlinepart partitions found on MTD device phys_mapped_flash Creating 5 MTD partitions on phys_mapped_flash: 0x-0x0020 : k4 mtd: Giving out device 0 to k4 0x0020-0x0040 : k6 mtd: Giving out device 1 to k6 0x0040-0x0080 : rd mtd: Giving out device 2 to rd 0x0080-0x00c0 : jffs2 mtd: Giving out device 3 to jffs2 0x00c0-0x0200 : others mtd: Giving out device 4 to others VFS: Cannot open root device 31:03 or unknown-block(31,3) Please append a correct root= boot option Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,3) 0Rebooting in 180 seconds.. ==
VFS: Cannot open root device 31:03 or unknown-block(31,3)
On Monday 02 January 2006 15:48, HappyPhot wrote: Hi, I've suffered for many days and google almost every where. I would like to boot from the flash with jffs2 (i.e. using jffs2 as my root /) . But it alyaws shows: VFS: Cannot open root device. (whole message is as below) Anybody knows what may cause this ? Please help and thank you. [...] You omitted the interesting part of the log output, the bootarguments at the very beginning. What is the value of root= ? Maybe you made the typical mistake of specifying /dev/mtd3 instead of /dev/mtdblock3, or you didn't compile in support for mtd access as a block device? Greetings, -- David Jander
