srvgrp-management.adoc

Service Group - MANAGEMENT_MODE (SERVICEGROUP_ID: 0x000A)

This MANAGEMENT_MODE service group provides RPMI client a mechanism to invoke the Management Mode (MM) in a secure execution environment. For general background on Management Mode, refer to the Platform Initialization (PI) specifications cite:[PI], Volume 4: Management Mode Core Interface.

The Management Mode (MM) provides an environment for implementing OS agnostic MM services such as secure variable storage, and firmware updates in the platform firmware. The MANAGEMENT_MODE service group defines RPMI services for invoking an MM service synchronously where the MM_COMMUNICATE RPMI service is used as a synchronous call from the non-secure world to the secure world and the data exchanged with the MM service is passed via special Management Mode (MM) shared memory.

The following table lists the services in the MANAGEMENT_MODE service group:

Table 1. MANAGEMENT_MODE Services

Service ID	Service Name	Request Type
0x01	MM_ENABLE_NOTIFICATION	NORMAL_REQUEST
0x02	MM_GET_ATTRIBUTES	NORMAL_REQUEST
0x03	MM_COMMUNICATE	NORMAL_REQUEST

Notifications

This service group does not support any events for notification.

Service: MM_ENABLE_NOTIFICATION (SERVICE_ID: 0x01)

This service allows the application processor to subscribe to MANAGEMENT_MODE service group notifications. The platform may optionally support notifications for events that may occur. The platform microcontroller can send these notification messages to the application processor if they are implemented and the application processor has subscribed to them. The supported events are described in Notifications.

Table 2. Request Data

Word	Name	Type	Description
0	EVENT_ID	uint32	The event to be subscribed for notification.
1	REQ_STATE	uint32	Requested event notification state Change or query the current state of EVENT_ID notification. 0: Disable 1: Enable 2: Return current state. Any other values of REQ_STATE field other than the defined ones are reserved for future use.

Table 3. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return error code Error Code Description RPMI_SUCCESS Event is subscribed successfully. RPMI_ERR_INVALID_PARAM EVENT_ID or REQ_STATE is invalid. RPMI_ERR_NOT_SUPPORTED Notification is not supported. Other errors [table_error_codes]
1	CURRENT_STATE	uint32	Current EVENT_ID notification state 0: Notification is disabled 1: Notification is enabled. In case of REQ_STATE = 0 or 1, the CURRENT_STATE will return the requested state. In case of an error, the value of CURRENT_STATE is unspecified.

Service: MM_GET_ATTRIBUTES (SERVICE_ID: 0x02)

This RPMI service gets the attributes about Management Mode, including MM version, MM shared memory location, etc.

Table 4. Request Data

NA

Table 5. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return error code Error Code Description RPMI_SUCCESS Service completed successfully. Other errors [table_error_codes]
1	MM_VERSION	uint32	Management Mode version. Bits Description [31:16] Major version [15:0] Minor version
2	MM_SHMEM_ADDR_LOW	uint32	Lower 32-bit of the MM shared memory physical address.
3	MM_SHMEM_ADDR_HIGH	uint32	Upper 32-bit of the MM shared memory physical address.
4	MM_SHMEM_SIZE	uint32	The size of MM shared memory in bytes.

Service: MM_COMMUNICATE (SERVICE_ID: 0x03)

The MM_COMMUNICATE service invokes an MM service implemented in the secure execution environment. The input data needed to identify and invoke the MM service is referred to as MM_COMM_INPUT_DATA whereas the output data returned by the MM service is referred to as MM_COMM_OUTPUT_DATA. The RPMI client in the non-secure execution environment provides the location of MM_COMM_INPUT_DATA and MM_COMM_OUTPUT_DATA in the MM shared memory as parameters of MM_COMMUNICATE service.

Table 6. Request Data

Word	Name	Type	Description
0	MM_COMM_INPUT_DATA_OFFSET	uint32	The offset in the MM shared memory where the input data is passed to the MM service.
1	MM_COMM_INPUT_DATA_SIZE	uint32	The size of the input data in the MM shared memory.
2	MM_COMM_OUTPUT_DATA_OFFSET	uint32	The offset in the MM shared memory where the output data will be written by the MM service.
3	MM_COMM_OUTPUT_DATA_SIZE	uint32	The maximum size of the output data which can be written by the MM service in the MM shared memory.

Table 7. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return error code Error Code Description RPMI_SUCCESS Service completed successfully. RPMI_ERR_INVALID_ADDR Input data end (or Output data end) is outside MM shared memory. RPMI_ERR_DENIED Denied due to no permission. Other errors [table_error_codes]
1	MM_COMM_RETURN_DATA_SIZE	uint32	Actual size of the output data written by the MM service in the MM shared memory.