Problem::VFS: can't find root device (self compiled busybox)

Help with booting MiniMyth

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andy_scorpion
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Problem::VFS: can't find root device (self compiled busybox)

Post by andy_scorpion » Sun Mar 14, 2004 10:07 am

Hi,

Well, I dicided to follow instruction from URL http://www.viaarena.com/?PageID=379. but stamble at stage after mounting cramfs filesystem

RAMDISK: cramfs filesystem found at block 0
RAMDISK: Loading 1060 blocks [1 disk] into ram disk... done
VFS: Mounted root (cramfs filesystem).
Mounted devfs on /dev
VFS: Cannot open root device "" on 03:42
Please append a correct "root=" boot option
Kernel panic: VFS: Unable to mount root fs on 03:42

pxelinux.conf/default

PROMPT 1
DEFAULT linux-ramdisk
DISPLAY messages
TIMEOUT 5
label linux-ramdisk

KERNEL bzImage.my
# don't use quotes on the append line
APPEND initrd=rootfs.my ramdisk_blocksize=4096 ramdisk=21000 devfs=mount

I have checked a few times that I didn't make any mistake from instruction and found everything correct. I guess that or instruction could be missing something or it could be RedHat 8 specific problem (yes I run mkcramfs from instruction page).

Did somebody had this problem and how you overcome it? Where I should look for source of the problem? The message above states that root was mounted but a little latter reports that kernel can not open root device -- it sounds a little confusing.

Andy

lmatter
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Post by lmatter » Sun Mar 14, 2004 10:22 am

I don't know off hand. This error is usualy difficult to debug because there is not much information.

I would try taking minimyth-0.4rc1 tar file and craming it and see if you can get that to boot. You will probably want to set MMNOXINIT=true in the pxeconfig append line to keep it from trying to run mythfrontend.

If you can boot that, then you know your pxe and mkcramfs are ok. Then we can look at the instructions from the article.

Larry

P.S. Congratulations. You are forum member #100.

andy_scorpion
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Post by andy_scorpion » Sun Mar 14, 2004 6:15 pm

Hi Larry,

minimyth-0.4rc1 boots just fine and I coud not find anything wrong except that I can not use mouse and keyboard (getting first screen with options to watch video, listen music ... and setup, as only I touch mouse or keyboard something happens as I can not use KVM switch any more. But I still can telnet minimyth box). At the moment I do not have infrared sensor connected to my minimyth box yet. And because of it I could not test minimyth further (Does anybody knows where I could find TSOP1738 or compatible item)

Well I will try to folllow your advice to mkcramfs minimyth-0.4rc1 and see what I will get. I have some filling that I am missing sometihing and it is something simple. But I am not sure where I should look for the problem.

NOTE: I will make a makefile to generate bzImage and rootfs according your instructions so that people have to type only "make" and magic start to happen. In this case you will be able to test my settings on your side what could give you more information about the problem.

Andrey

hagan
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Post by hagan » Sun Mar 14, 2004 8:17 pm

Maybe its just the file access permissions. Set it to world readable for your root image.

Marcus

andy_scorpion
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Post by andy_scorpion » Tue Mar 16, 2004 4:18 am

Hi Larry,

I've made a makefile for busybox linux installation based on your article. You can download it and give it a try

http://www.andromedasystems.net/~andreyv/makefile.bz2

I would say that makefile is way far from perfect but should work (main problem is that used software are spread on different servers and I didn't analyse all dependencies). If you do not mind I would like to get some feedback from you regarding makefile.

Andrey

andy_scorpion
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I got it working but I am missing ifconfig

Post by andy_scorpion » Wed Mar 17, 2004 9:19 am

Hi Larry,

I figured out what was wrong and now I am able to boot. But I found that I am missing ifconfig command. I do not remember that you mentioned how you got it compiled. I mean that I didn't see a reference for tarball and where you download it from in your artickle. Could you post this information in this thread and if possible add it to your article?

Thank you in advance,

Andy

lmatter
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Post by lmatter » Wed Mar 17, 2004 9:23 am

Hi Andy,

It's in the article. In the "build a basic set of commands" section. Uncomment line 57 of Config.h

Larry

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Post by andy_scorpion » Wed Mar 17, 2004 9:25 am

Hi Larry,

I just found this information. Sorry it is my fault -- somehow I missed this part when I was reading your article. At the moment I am recompiling busybox.

I just finished installation and did mkcramfs -- it works, I was able to ping yahoo.com. Well now I would like to ask you about your future article -- When do you plan to write it? I can not wait when it will be published.

Andy

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Post by lmatter » Wed Mar 17, 2004 9:34 am

I'm not sure. I was planning on February, then March, and now it looks like April before I will have a chance.

But you can always disect the current Minimyth distro. Also, you may want to look at the GAR CVS (there are some threads here that discuss it). You can look at the Makefiles and manifests to see what needs to be copied. It's not complete but it is very close.

Larry

hagan
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Post by hagan » Tue Mar 30, 2004 9:36 am

I figured out what was wrong and now I am able to boot.


Hi Andy,
can you please tell us how you solved your problem. So anybody having the same problem can profit from your work.

Regards
Marcus

Eduardo
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Post by Eduardo » Tue Mar 30, 2004 8:34 pm

Finding A TSOP.

Andy I'm also in Canada and had a hell of a time tracking down a TSOP. I called about 6 local and 2 national electronic components stores. None of them had anything (including radio shack, that part number is mysteriously absent in canada).

One National place had them for about $30 canadian, a little insane. I would recommend ordering from a Radio Shack in the states, or in my case I grabbed a broken sattelite receiver and remote and cut the TSOP off the board.

It was still pretty hard to find any data sheets on the TSOP I cut off, and in the end, found that one pin is offset a little more than the other 2. (ie they are not spaced evenly). Some of the homebrew wiring diagrams show the TSOP pinout with the offset visible, and you just wire it the same... If not trial and error.

Other problems:
- I also ended up with the wrong Voltage regulator, but if you grab the 5 volts of the USB you don't need a voltage regulator at all.
- I also ended up with the wrong resistor strength (you gotta watch those clerks as they collect the components for you!). I found another resistor that was close in size, and it works fine. (I got the color codes from the web and cut a similar resistor off the busted sattelite receiver).
- edit the lircrc file from the mini-myth distro. I downloaded one from the web to use as a basis and it was a completely different format.

Hope you get the remote working!

BTW if you do plug in a keyboard, make sure you include a mouse as well, for some bizzare reason you have to have both or it won't work.

lmatter
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Post by lmatter » Tue Mar 30, 2004 9:17 pm

If they will ship to canada, I would get a tsop1738 from here:
http://www.newark.com/NewarkWebCommerce ... id=95B4865

Larry

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