CPIO question

nekkro-kvlt · 06-08-2009, 07:44 AM

Hi all, I have a trouble with CPIO:
I have a file called asa802. I extract it with the following command:

Quote:

bastien@bastien-laptop:~/asaemu/asa802-k8_1$ cd uncompressed/
bastien@bastien-laptop:~/asaemu/asa802-k8_1/uncompressed$ rm -rf *
bastien@bastien-laptop:~/asaemu/asa802-k8_1/uncompressed$ cpio -id --no-absolute-filenames < ../asa802

Then I tried to rebuild archive:

Quote:

bastien@bastien-laptop:~/asaemu/asa802-k8_1/uncompressed$ find . | cpio -o > asa802_cpio
61020 blocks
bastien@bastien-laptop:~/asaemu/asa802-k8_1$ ls -la
total 157924
drwx------ 3 bastien bastien 4096 2009-06-08 14:36 .
drwxr-xr-x 5 bastien bastien 4096 2009-06-08 14:16 ..
-rw-r--r-- 1 bastien bastien 31251968 2009-06-08 14:18 asa802
-rw-r--r-- 1 bastien bastien 31242240 2009-06-08 14:36 asa802_cpio
drwxr-xr-x 12 bastien bastien 4096 2009-06-08 14:34 uncompressed

Filesizes are not identical !

As I saw these messages:

Quote:

pio: dev/ram0: Cannot mknod: Opération non permise
cpio: dev/mem: Cannot mknod: Opération non permise
cpio: dev/kmem: Cannot mknod: Opération non permise
cpio: dev/null: Cannot mknod: Opération non permise
cpio: dev/port: Cannot mknod: Opération non permise
cpio: dev/hda: Cannot mknod: Opération non permise
...

I tried:

Quote:

bastien@bastien-laptop:~/asaemu/asa802-k8_1$ cd uncompressed/
bastien@bastien-laptop:~/asaemu/asa802-k8_1/uncompressed$ rm -rf *
bastien@bastien-laptop:~/asaemu/asa802-k8_1/uncompressed$ sudo cpio -id --no-absolute-filenames < ../asa802

And messages disappears, but filesizes are still not identical

Tried also without the -h newc parameter, but same problem.
Do you know why ? The problem is not that the archive has a different size, but when I boot with the original archive (it's a unix FS, i boot it with QEmu), it works, and the second case got an error. I think it's maybe I extract with --no-absolutes-filenames, and when I zip it again, the filenames are wrong, but how should I fix it, as I can't extract it in my FS, it would overwrite some of my system files :s

Thanks for your help

aus9 · 06-09-2009, 08:16 PM

hi

I have not studied what you have attempted to modify but as an alternative to unpack repack cpios...try this...assuming you have full file permissions....otherwise do it as root

Code:

pwd ....response is your home dir of course

mkdir cpio/
cp /pathwayto/cpiofile  /home/yourname/cpio/....means put a file into new folder..keeping oldfile as backup
cd cpio/...........................................go into folder
cpio -iv < cpiofile.....unpacks it
rm -f cpiofile...............................delete old file

do your mods....

Code:

ls | cpio -ov newcpiofilename...........create new cpio

try to use a different filename for new cpio so you know which is which?

nekkro-kvlt · 06-10-2009, 03:13 AM

Hi, I finally found the pain, by hexediting the cpio made file, I saw that when I was doing ls uncompressed/ it added uncompressed in the archive, so I made
cd uncompressed
find . -print | cpio -o -H newc > ../newfile

exporting into another folder is important, otherwise the created file will be found by find and included... It is not the exact same size, but the then I can boot it with QEmu.

I had also needed to extract CPIO File with root privileges, or it wasn't able to change attributes...

Thanks anyway