Passing Ratchet Status to Guest OS
Ratchet fuse burning status is passed to guest OS via the kernel device tree. There are separate nodes for MB1, MTS, and MB1-BCT at the following location under the /proc interface.
/proc/device-tree/chosen/ratchet-update-statusEach node has one field: status, which can have the following strings:
| Ratcheting Status | Description |
|---|---|
| not attempted | Default status. Ratchet check path is skipped. |
| skipped - opt-in fuse not set | Ratchet update check skipped as opt-in fuse is not set by the OEM. |
| failed - to burn fuse | Ratchet fuse update(burning) failed. |
| failed - to get active fw ratchet val | Failed to get the firmware ratchet value for active boot chain. |
| failed - to get in-active fw ratchet val | Failed to get the firmware ratchet value for in-active boot chain. |
| skipped - hw_ratchet matches sw_ratchet | Hardware ratchet value matches software ratchet value. |
| skipped - active chain ratchet is 0 | Ratchet update check skipped as the active chain ratchet is 0. |
| skipped - fw not found | Ratchet update check skipped as the firmware is not found. |
| updated - ratchet to | Ratchet fuses are successfully updated with the software ratchet value. |