I believe that I may have made a discovery, it might have already been found, and I searched for it and found 0 results, but just in case, here it is.

The iPhone firmware updates, in .ipsw format can be opened with 7-zip.

If you rename the file from "Something".ipsw to "Something".7z and open it with 7-zip, you will see a simple directory structure. (Using 2.2 3G for this example.)

(See attachment for the example)

The archive contains many dmg type files, and some crazy ones. (.s5l8900x)?



Anyway, Thank you,

IceRayn

Excellent find!

I am curious, have you tried to mount the .DMG's?

.ipsw fies are just regular ZIP files, like the IPAs (apps)

You can rename the firmware to .ZIP and decompress with the archive utility that is already installed on Mac OS.

You can decompress with 7zip because it can decompress regula zip files (there is also a 7Zip utility for Mac).

This also applies to IPAs

So basically you dont need to install aditional software to decompress thos files.

the s5l8900x file is basically a kernel file.

If your iphone is Jailbroken you can see the file on one of the System directories.

Its actually a bit annoying that this is true, especially when trying to jailbreak. I had to download my ipsw file 3 times before i realised safari was unarchiving it automatically!