ot_keymgr: Add main FSM with keymgr initialization
#184
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Progresses lowRISC/opentitan#27894 |
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Introduce the initial logic comprising the keymgr FSM, stubbing out all internal FSM states apart from the `RESET` state, which is implemented. Note however that this will not currently function, because keymgr enablement via lc_ctrl has not yet been added. Adds logic for scheduling the FSM using a short timer (200 ns) instead of a BottomHalf because of potential reliability issues. Using a BH / Timer allows deferring execution to the end of I/O calls. Signed-off-by: Alex Jones <alex.jones@lowrisc.org>
When the keymgr is disabled by the lc_ctrl, this also temporarily locks the CFG_REGWEN. Signed-off-by: Alex Jones <alex.jones@lowrisc.org>
Signed-off-by: Alex Jones <alex.jones@lowrisc.org>
Add a device link to endpoint 0 of EDN0 through which the Keymgr can request entropy for refreshing its seed. Implements the `ENTROPY_RESEED` and `RANDOM` states for the Keymgr FSM which use this connection. Signed-off-by: Alex Jones <alex.jones@lowrisc.org>
Adds a connection between the keymgr and the otp_ctrl, using the implemented `otp_ctrl` methods to retrieve the creator root key from OTP. Also change the behaviour of the `ROOT_KEY` FSM state so that an invalid root key (or disablement) will cause a transition to the `WIPE` state. Signed-off-by: Alex Jones <alex.jones@lowrisc.org>
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This commit focuses on creating a (mostly complete) implementation of the `INIT` keymgr FSM state, which performs some checks before starting an advance or disable operation. These are both stubbed out for now. Logic (which is the same as the keymgr_dpe logic) is added for updating the `OP_STATUS`, so that it latches and reflects the last requested operation. Also, functionality is added to lock `CFG_REGWEN` during an operation. Signed-off-by: Alex Jones <alex.jones@lowrisc.org>
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This PR is the second of a series of 4 PRs to implement OpenTitan's
keymgrIP, as used in Earlgrey, split to ease review. You can see all the relevantkeymgrcommits in #188.This PR implements the initialization logic and FSM states for the keymgr, allowing the keymgr to begin operation upon writing a
STARTcommand to the keymgr. This includes lifecycle controller enablement, entropy reseeding from the EDN, Creator root key loading from the OTP, and implementation of operation status updates. Future PRs will continue to implement the main FSM andkeymgroperations.See the commit messages for more details about each change.