During the life of the device, the
state changes based on the current state of the device and the security settings
that are applied.
The following is sequence of steps for
transitioning from HS-FS to HS-KP.
- DSSM command
(DSSM_COMMAND_SECURE_KEY_PROVISIONING) shall be given by user to device.
- Eight RoT public keys (six for
secure boot and two for secure debug) is sent to the device.
- ROM marks the device as
HS-KP.
The following is sequence of steps for transition from HS-KP to
HS-SE.
- If the debug port is not locked,
then application/CSC can be programmed using the debug port.
- Alternatively invoke BSL to
program the application
- Program the signed CSC or
application over BSL
- Once ROM validates the CSC or
application, the device is marked as HS-SE
The following is sequence of steps for
transition from HS-KP/HS-SE to HS-FA.
- DSSM command (DSSM_COMMAND_RMA)
shall be given by user to device
- If Combined certificate is
received and validated then ROM Marks the device as HS-FA
- Device goes to HS-FA
Authenticated Flow
To convert the device to DCOM/BAD, user can send DSSM command
(DSSM_COMMAND_CONVERT_BAD_DEVICE).
Note: Customer return flow Customers need to transition the
device to HS-FA state from HS-KP / HS-SE before sending the device back to TI for
failure analysis. Customer has the option to secure the different assets (for
example, code, keys, and others.) by programming / erasing them. Be aware that
erasing the content will restrict and limit the debug of some of the failures (for
example, flash data retention failure cannot be debugged once the content is
erased).