IMG4 File Format

There is an img4 file (sep-firmware.img4) found in the IPSWFILE/Firmware/all_flash/all_flash.DEVICEIDENTIFIER.production for any A7 (64bit) device. It has a IMG40 header, but also refers to IM4P File Format.

The IMG40 structure is as follows:

sequence [
   0: string "IMG40"
   1: string encryption type - IM4P
   2: string type - sepi (Secure Enclave Processor Image), ...
   3: ...
]

This software article is a "stub", an incomplete page. Please add more content to this article and remove this tag.