extracting data from oem.img and system.img under linux

[belegdol]

Hello,

I am trying to investigate the contents of the stock rom. I have downloaded the zip and extracted it, and also converted the sparse image files to nonsparse ones with simg2img. Unfortunately, I am still unable to mount the images. No matter whether I try to mount the converted image as ext2, ext4 or f2fs, I am getting the error:

mount: /mnt/temp: wrong fs type, bad option, bad superblock on /dev/loop0, missing codepage or helper program, or other error.

Does anybody know if/how can the oreo stock images for griffin be mounted? The issue seems to be specific to motorola or oreo as I was able to mount files from nexus 5x oreo stock images without issues. Thank you for the advice.

 

[belegdol]

It turns out motorola images have 128kb header which needs to be removed before they can be mounted. Assuming dd's default block size of 512 bytes this gives the following:

$ dd if=system.raw.img of=system.raw.img.fixed skip=256

After that the images can be mounted.