In-System Programming (ISP) Forensics
In-System Programming (ISP) is the ability of to program devices while installed in a complete system, rather than requiring the chip to be programmed prior to installing it into the system. In-system programming (ISP) can also be called In-Circuit Serial Programming (ICSP).
ISP, in a forensic application, is an acquisition procedure which involves connecting to specific points on the device to directly read a component. This process bypasses the devices CPU as it reads the component directly. The specific points used are essentially the visible points on the PCB which connect to the hidden points underneath the chip. For this reason, these points are direct electrical connections to the chip you are trying to read.
ISP can therefore be used to directly read the device storage such as the eMMC which will provide you with a raw binary image of the chip. Performing an ISP procedure on supported phones can be an extremely effective technique to extract a full physical image from devices without having to resort to a chip-off procedure which is destructive. Once completed, the phone or device can be re-assembled and should function normally.
|Default BGA 169 eMMC pinout taken from: ([How to find direct eMMC pinout])|