Prototypes
Apple prototypes are very similar to production Apple devices, they feature SecureROM, iBoot and Darwin. Although there are some differences:
- System installed - NonUI or Internal UI
- Bootloader - DEVELOPMENT or DEBUG
- CPFM (Chip fusing mode)
There are also different stages of prototypes. The common ones are listed below:
- PROTO0
- PROTO1
- PROTO2
- PREEVT
- EVT
- PREDVT
- DVT
- PREPVT
- PVT
EVT, DVT, PVT are the key part, others are just a matter of production date. PVT is similar to production device because it has CPFM 03. However it runs factory firmware - mostly DEVELOPMENT bootloaders and NonUI. DVT devices usually have CPFM 01 meaning you can debug AP. Such devices can't debug SEP. secure SEP and insecure AP. DVTs are known to run Internal UI, but they can also run NonUI or no system at all - just iBoot. And finally, the most powerful devices - EVTs. EVTs are "insecure". They have CPFM 00 and that means you can debug both SEP and AP. Fun fact - EVTs mostly run LLDiagFilesystem or no OS. For debugging purposes or to run unsigned code on device which has CPFM 01 or CPFM 00 you can use astris.