Image - inspect with flashing, a second post

[manywrt]

I got instructions on how to inspect an OpenWrt image without having to flash a router with it, here:

Inspecting an image (firmware) without installing

gunzip openwrt-*.img.gz sudo partx -a openwrt-*.img losetup ls /dev/loop* sudo mount /dev/loop0p2 /mnt cat /mnt/usr/lib/opkg/status ls /mnt/etc/{board.d,uci-defaults,config}

But now that I am actually about to try it, I get suck at step 1. Namely, the instructions assume that I have a *.img file when all my images, whether downloaded or created using make image, are a *.bin.

When I try to go through nevertheless, replacing sudo partx -a openwrt-*.img with sudo partx -a openwrt-*.bin, I get:

partx: /dev/loop20: failed to read partition table

What next?

[vgaetera]

I'm afraid, this kind of image is significantly more problematic to inspect:

The OpenWrt Flash Layout

You need to identify the exact offset/sizelimit parameters for each partition.
That allows you to split/map/mount the partitions and access the filesystem.

The following reply should be more suitable in your case:

Inspecting an image (firmware) without installing

One of them best tools for inspecting any binary image in general would be binwalk.

[manywrt]

@vgaetera

this kind of image is significantly more problematic to inspect

Thanks for that clarification. So, unless I would make it a project for understanding the topic, it'd be quicker to buy a spare router for "flash and inspect."

By the way, did you change the accepted "solution" for my other post for me? I went there to do that, but it had already been done.

[sumo]

@manywrt

Thanks for that clarification. So, unless I would make it a project for understanding the topic, it'd be quicker to buy a spare router for "flash and inspect."

Well, did you try binwalk? It should really figure out all those offsets and stuff on its own. It has a flag to automatically extract whatever it finds, even recursively aka matroska-style .

binwalk -eM whatever_image.binary

[manywrt]

@sumo

It should really figure out all those offsets and stuff on its own.

Thanks for that encouragement! Last couple of weeks for this OpenWrt setup was the first time ever I used chmod, scp, tar, etc., each one of them taking hours of reading and experimentation while I tried to figure out just the basics (effect of a chance dot or slash etc.). So an advanced project like binwalk will take me some time.