EH_STATE Features
- EH_STATE allows for fast device startup by not employing the hardware Root of Trust in the system.
- The boot process bypasses the application authentication steps, performing only cursory checks on the application before trying to execute it.
- allows some level of debug port locking; the user can specify a 128-bit key that is stored in NVM.
- This key, once present, is used by the ROM to enforce the debug port locking functionality.
- Once a device is locked, the debug port can only be accessed by the provision of the key through the Data Exchange Unit (DEU).
- The state also allows for a specific to be written to each device, which can be read back at a later stage by the DEU if required.
- This enables device manufacturers to identify their devices uniquely if needed.
- The SOC ID in EH mode is a 32-bit value. For more detail about the SOC ID, see Setting the SOC ID.