HSM (M4) has the primary ownership of
the device at boot up and does the following tasks:
- PLL Initialization and Lock
- Run MPOST based on input from
SECCFG settings input by user
- Run LPOST based on input from
SECCFG settings input by user
- IPC Initialization and C29 CPU1
reset release
- C29 Application Image
authentication
- C29 SBL validation and integrity
check
- HSMRT validation and integrity
check
C29 SBL (Secondary Bootloader)
authentication process:
- Initialize Boot Peripheral to
receive the image
- Copies image from host and loads
into LDA RAM
- After copying, C29 sends IPC
message to HSM
- HSM starts certificate validation
and image integrity checks
- HSM sends ACK back to C29 CPU1
and copies image from LDA to LPA RAM in case image authentication succeeds
- If the image authentication
fails, then HSM retries the process again for a maximum of 5 times
HSMRT (HSM Realtime App)
authentication process:
- SBL downloads HSMRT from the
peripheral bootloader chosen by user
- SBL copies HSMRT image at LDA
RAM
- C29CPU sends IPC message to HSM
after copying image
- HSM protects LDA memory and
starts certificate and image validation
- HSM branches to LDA and releases
protection in case of successful validation
- In case of failure, send NACK
message to C29 CPU1