Registers

The revocation bitmap is not a register but a memory window on the revbm interface; see the Theory of Operation.

Summary

INTR_STATE

Interrupt State Register

• Offset: 0x0
• Reset default: 0x0
• Reset mask: 0x1

Fields

{"reg": [{"name": "tbre_done", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"bits": 31}], "config": {"lanes": 1, "fontsize": 10, "vspace": 110}}

INTR_ENABLE

Interrupt Enable Register

• Offset: 0x4
• Reset default: 0x0
• Reset mask: 0x1

Fields

{"reg": [{"name": "tbre_done", "bits": 1, "attr": ["rw"], "rotate": -90}, {"bits": 31}], "config": {"lanes": 1, "fontsize": 10, "vspace": 110}}

INTR_TEST

Interrupt Test Register

• Offset: 0x8
• Reset default: 0x0
• Reset mask: 0x1

Fields

{"reg": [{"name": "tbre_done", "bits": 1, "attr": ["wo"], "rotate": -90}, {"bits": 31}], "config": {"lanes": 1, "fontsize": 10, "vspace": 110}}

ALERT_TEST

Alert Test Register

• Offset: 0xc
• Reset default: 0x80000000
• Reset mask: 0x80000001

Fields

{"reg": [{"name": "fatal_fault", "bits": 1, "attr": ["wo"], "rotate": -90}, {"bits": 30}, {"name": "regwen", "bits": 1, "attr": ["rw0c"], "rotate": -90}], "config": {"lanes": 1, "fontsize": 10, "vspace": 130}}

TBRE_REGWEN

Write enable for the revocation engine registers.

• Offset: 0x10
• Reset default: 0x1
• Reset mask: 0x1

Fields

{"reg": [{"name": "en", "bits": 1, "attr": ["ro"], "rotate": -90}, {"bits": 31}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

TBRE_BASE_ADDR

Address of the first capability the revocation engine sweeps.

• Offset: 0x14
• Reset default: 0x0
• Reset mask: 0xfffffff8
• Register enable: TBRE_REGWEN

Fields

{"reg": [{"bits": 3}, {"name": "addr", "bits": 29, "attr": ["rw"], "rotate": 0}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

TBRE_NUM_CAPS

Number of capabilities the revocation engine sweeps, each of them two 32-bit words.

• Offset: 0x18
• Reset default: 0x0
• Reset mask: 0x7fffffff
• Register enable: TBRE_REGWEN

Fields

{"reg": [{"name": "num", "bits": 31, "attr": ["rw"], "rotate": 0}, {"bits": 1}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

TBRE_START

Starts a sweep over the capabilities TBRE_BASE_ADDR and TBRE_NUM_CAPS describe. TBRE_STATUS.busy reflects the sweep in progress. A start outside CHERIoT mode, with TBRE_NUM_CAPS zero, or with TBRE_BASE_ADDR outside the tagged regions, is ignored and sets TBRE_STATUS.start_err.

• Offset: 0x1c
• Reset default: 0x0
• Reset mask: 0x1
• Register enable: TBRE_REGWEN

Fields

{"reg": [{"name": "start", "bits": 1, "attr": ["wo"], "rotate": -90}, {"bits": 31}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

TBRE_STATUS

Status of the revocation engine.

• Offset: 0x20
• Reset default: 0x0
• Reset mask: 0x301

Fields

{"reg": [{"name": "busy", "bits": 1, "attr": ["ro"], "rotate": -90}, {"bits": 7}, {"name": "start_err", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"name": "sweep_err", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"bits": 22}], "config": {"lanes": 1, "fontsize": 10, "vspace": 110}}

TBRE_STATUS . sweep_err

A response to the revocation engine was an error, failed its integrity check or was malformed, or the RMW filter reported a fault, during a sweep. Except for an error response to a read of the swept memory, the fatal_fault alert is raised as well. Stays set until software writes 1 to it.

TBRE_STATUS . start_err

A start was ignored because the subsystem was not in CHERIoT mode, TBRE_NUM_CAPS was zero or TBRE_BASE_ADDR was outside the tagged regions. Stays set until software writes 1 to it.

TBRE_STATUS . busy

The revocation engine is sweeping; it is low once every capability of the sweep is resolved.

TBRE_EPOCH

Sweep epoch, twice the number of sweeps that ended without an error, plus one while the revocation engine is active. It is odd from the cycle a start is taken, when TBRE_REGWEN falls, until the engine is inactive again, and even otherwise. A sweep that ends with an error (see TBRE_STATUS.sweep_err) is not counted, so the epoch returns to the even value it had before that start, and no software waiting for a completed sweep proceeds on it.

• Offset: 0x24
• Reset default: 0x0
• Reset mask: 0xffffffff

Fields

{"reg": [{"name": "active", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "count", "bits": 31, "attr": ["ro"], "rotate": 0}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}