LinuxQuestions.org - [SOLVED] How to detect file system of a ramdisk.img?

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How to detect file system of a ramdisk.img?

Hello friends,

I would like to see what are inside of ramdisk.img and system.img

please see the properties of this img:

Code:

root@benjamin-virtual-machine:/GPL/tmp# file ramdisk.img 

ramdisk.img: u-boot legacy uImage, hRamdisk, Linux/ARM, RAMDisk Image (Not compressed), 168988 bytes, Mon Oct 10 14:45:04 2011, Load Address: 0x41000000, Entry Point: 0x41000000, Header CRC: 0x103531EB, Data CRC: 0xABED82A4

root@benjamin-virtual-machine:/GPL/tmp#

root@benjamin-virtual-machine:/GPL/tmp# file system.img 

system.img: VMS Alpha executable

root@benjamin-virtual-machine:/GPL/tmp#

I am new learner of embedded system. Can any friend here teach me what is the basic procedure for viewing the contents of a ramdisk.img or system.img?
Any ideas will be appreciated.

Usually, RAM disks are compressed cpio archives. How to View, Modify and Recreate initrd.img has a decent summary of how to manipulate one.

--- rod.

Hello theNbomr,

As you can see the code, it(ramdisk.img) is Not compressed. Anyway, I have tried your advice.

Code:



  root@gpl-vm:/GPL# mv ramdisk.img ramdisk.gz

root@gpl-vm:/GPL# gunzip ramdisk.gz 



gzip: ramdisk.gz: not in gzip format

root@gpl-vm:/GPL#

So, then skip the decompression part. Just de-archive it with cpio.
--- rod.

Hello theNbomr,

You are right, I tried this:

Code:

root@benjamin-virtual-machine:/GPL/tmp/ramdisk# file ramdisk.img 

ramdisk.img: u-boot legacy uImage, hRamdisk, Linux/ARM, RAMDisk Image (Not compressed), 168988 bytes, Mon Oct 10 14:45:04 2011, Load Address: 0x41000000, Entry Point: 0x41000000, Header CRC: 0x103531EB, Data CRC: 0xABED82A4

root@benjamin-virtual-machine:/GPL/tmp/ramdisk# dd if=ramdisk.img of=./out64c bs=64c skip=1

2640+1 records in

2640+1 records out

168988 bytes (169 kB) copied, 0.0275843 s, 6.1 MB/s

root@benjamin-virtual-machine:/GPL/tmp/ramdisk# ll

total 344

drwxr-xr-x 2 root root  4096 Nov 11 10:45 ./

drwxr-xr-x 6 root root  4096 Nov 11 10:29 ../

-rw-r--r-- 1 root root 168988 Nov 11 10:45 out64c

-rw-r--r-- 1 root root 169052 Nov  9 21:56 ramdisk.img

root@benjamin-virtual-machine:/GPL/tmp/ramdisk# file out64c 

out64c: gzip compressed data, from Unix

root@benjamin-virtual-machine:/GPL/tmp/ramdisk# cp out64c out64c.gz

root@benjamin-virtual-machine:/GPL/tmp/ramdisk# mv out64c ../

root@benjamin-virtual-machine:/GPL/tmp/ramdisk# gzip  -d out64c.gz 

root@benjamin-virtual-machine:/GPL/tmp/ramdisk# ll

total 448

drwxr-xr-x 2 root root  4096 Nov 11 12:08 ./

drwxr-xr-x 6 root root  4096 Nov 11 12:08 ../

-rw-r--r-- 1 root root 276736 Nov 11 12:07 out64c

-rw-r--r-- 1 root root 169052 Nov  9 21:56 ramdisk.img

root@benjamin-virtual-machine:/GPL/tmp/ramdisk# cpio -i -F out64c 

541 blocks

root@benjamin-virtual-machine:/GPL/tmp/ramdisk# ll

total 608

drwxr-xr-x 8 root root  4096 Nov 11 14:46 ./

drwxr-xr-x 6 root root  4096 Nov 11 12:08 ../

drwxrwx--x 2 root root  4096 Nov 11 14:46 data/

-rw-r--r-- 1 root root    118 Nov 11 14:46 default.prop

drwxr-xr-x 2 root root  4096 Nov 11 14:46 dev/

-rwxr-x--- 1 root root 107736 Nov 11 14:46 init*

-rwxr-x--- 1 root root  1677 Nov 11 14:46 init.goldfish.rc*

-rwxr-x--- 1 root root  17429 Nov 11 14:46 init.rc*

-rw-r--r-- 1 root root 276736 Nov 11 12:07 out64c

drwxr-xr-x 2 root root  4096 Nov 11 14:46 proc/

-rw-r--r-- 1 root root 169052 Nov  9 21:56 ramdisk.img

drwxr-x--- 2 root root  4096 Nov 11 14:46 sbin/

drwxr-xr-x 2 root root  4096 Nov 11 14:46 sys/

drwxr-xr-x 2 root root  4096 Nov 11 14:46 system/

root@benjamin-virtual-machine:/GPL/tmp/ramdisk#

Thank you very much.