custom applications in initrd not found

malo_umoran · 02-09-2008, 07:13 PM

Hi,

I am customizing my initrd and I have some problems with it.

I made a folder /scripts in /boot/initrd-tree and the scripts in this file are found and executed. But when I copy some binary files from /sbin/ to /boot/initrd-tree/sbin/ or bin/ the files are be found.

I copied "scp" and depending libs or "usplash", but files could not be found during boot. I unpacked initrd.gz and everything is there.

Did I forgot something or is there an additional step which have to be done, when putting some additional applications in the initrd?

Thanks

mastemmer · 02-10-2008, 12:48 PM

I figure you want these scripts to be run during boot.
The boot operation runs the script init in the root of the initrd image.
You may call your scripts by adding commands to this init.
Since there is no $PATH set yet you must use complete explicit paths to call programs.

M. Stemmer

malo_umoran · 02-10-2008, 01:35 PM

you did not understand me.

I am playing with initrd out of curiosity. Example:
I compiled "usplash" and copied executables from /sbin/ to /boot/initrd-tree/sbin.

I run "ldd /sbin/usplash":

Code:

	linux-gate.so.1 =>  (0xffffe000)
	libusplash.so => /lib/libusplash.so (0xb7ec4000)
	libc.so.6 => /lib/libc.so.6 (0xb7d82000)
	libdl.so.2 => /lib/libdl.so.2 (0xb7d7e000)
	/lib/ld-linux.so.2 (0xb7f31000)

so I copied /lib/libusplash.so, /lib/libc.so.6, /lib/libdl.so.2 and /lib/ld-linux.so.2 to /boot/inird-tree/lib.

I put in "init" file "/sbin/usplash" to run it during boot ... and I still get "file not found".

I tried also something else, just for fun. I copied /bin/mknod to /boot/initrd-tree/bin/mknod just to see whether this file will be found. I also copied /lib/libc.so.6 and /lib/ld-linux.so.2 to the initrd-tree/lib/ but still "file not found" ...

otot555 · 02-10-2008, 01:46 PM

Dear malo,

I think you did not express the situation clearly.
can you emphasize more.

thank you

gnashley · 02-10-2008, 03:05 PM

Since those are shared libs you are copying, you probably need to create and add an ld.so.cache file, or add ldconfig to your binaries and add an ld.so.conf file to the etc dir of the initrd and then run ldconf before running the other binaries which use shared libs.
A better bet is to compile usplash as a statically-linked binary so you don't have to fool with the rest.

malo_umoran · 02-10-2008, 03:13 PM

ok, one more try

I am trying to add some applications to initrd. But every binary file I add is not found during boot. It is probably a problem with missing libraries, but I did not find the solution.

problem history and root: I was looking for some kind of bootsplash program which have support for user input, because I wanted to let user enter luks-cryptsetup password in some of bootsplash gui and not on command line. "usplash" from ubuntu is able to do this and I decided to test it. I compiled it and copied executables to initrd-tree/sbin. I put a command to run usplash executable in initrd-tree/init, but I always get an error that "usplash" is not found. But the file is there.

1st idea: A few guys on irc#slackware told me to check usplash for missing libraries and include these in initrd. I found missing libs and I copied these in initrd-tree but still the same error.

2nd idea: usplash is maybe somehow invalid. I decided to test with an another file and I copied "mknod" from /bin to initrd-tree/bin. I put a command in initrd-tree/bin to run mknod but I again received the error that the file was not found. "ls" is also in initrd-tree/bin and it can be found (ls is symlink to busybox).

this is the output of "ldd /bin/mknod":

Code:

mm@x31:/boot/initrd-tree/bin$ ldd /bin/mknod 
	linux-gate.so.1 =>  (0xffffe000)
	libc.so.6 => /lib/libc.so.6 (0xb7e46000)
	/lib/ld-linux.so.2 (0xb7fa8000)

I copied all these libs to initrd-tree, made a new initrd, but "mknod" could not be found.

I am obviously doing something wrong... and I hope that you understand what I am trying to explain

.

malo_umoran · 02-10-2008, 03:25 PM

Quote:

Originally Posted by gnashley

Since those are shared libs you are copying, you probably need to create and add an ld.so.cache file, or add ldconfig to your binaries and add an ld.so.conf file to the etc dir of the initrd and then run ldconf before running the other binaries which use shared libs.
A better bet is to compile usplash as a statically-linked binary so you don't have to fool with the rest.

I wanted to compile it as static-linked lib but usplash has almost no documentation. I will have to check the source.

I did not thought about ldconf... I forgot that the file has no idea where to look for a lib. I have no idea why it tells that there is no sbin/usplash. I would expect to see an error message about missing libraries and not that the file does not exist.