srvgrp-base.adoc

Service Group: BASE (SERVICEGROUP_ID: 0x0001)

The BASE service group is mandatory and provides the following services:

• Initial handshaking between the application processor and the platform microcontroller.

• Discovering the RPMI implementation version information.

• Discovering the implementation of a service group.

• Discovering platform specific information.

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

Table 1. BASE Services

Service ID	Service Name	Request Type
0x01	BASE_ENABLE_NOTIFICATION	NORMAL_REQUEST
0x02	BASE_GET_IMPLEMENTATION_VERSION	NORMAL_REQUEST
0x03	BASE_GET_IMPLEMENTATION_ID	NORMAL_REQUEST
0x04	BASE_GET_SPEC_VERSION	NORMAL_REQUEST
0x05	BASE_GET_PLATFORM_INFO	NORMAL_REQUEST
0x06	BASE_PROBE_SERVICE_GROUP	NORMAL_REQUEST
0x07	BASE_GET_ATTRIBUTES	NORMAL_REQUEST
0x08	BASE_SET_MSI	NORMAL_REQUEST

RPMI Implementation IDs

Table 2. RPMI Implementation IDs

Implementation ID	Name
0x0	libRPMI cite:[libRPMI]

Notifications

This service is used by the platform microcontroller to send the asynchronous message of type notification to the application processor. The message transfers the events defined by this service group. The events defined are listed in the below table.

Table 3. BASE Service Group Events

Event ID	Event Name	Event Data	Description
0x01	REQUEST_HANDLE_ERROR	NA	This event indicates that the platform microcontroller is unable to serve the message requests.

Service: BASE_ENABLE_NOTIFICATION (SERVICE_ID: 0x01)

This service allows the application processor to subscribe to BASE 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 4. 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 5. 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: BASE_GET_IMPLEMENTATION_VERSION (SERVICE_ID: 0x02)

This service is used to get the RPMI implementation version of the platform microcontroller. The version returned is a 32-bit composite number containing the MAJOR and MINOR version numbers.

Table 6. Request Data

NA

Table 7. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return error code Error Code Description RPMI_SUCCESS RPMI implementation version returned successfully. Other errors [table_error_codes]
1	IMPL_VERSION	uint32	Implementation version Bits Description [31:16] MAJOR number [15:0] MINOR number

Service: BASE_GET_IMPLEMENTATION_ID (SERVICE_ID: 0x03)

This service is used to get a 32-bit RPMI implementation ID assigned to the software that implements the RPMI specification. Every implementation ID is unique and listed in the RPMI Implementation IDs.

Table 8. Request Data

NA

Table 9. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return error code Error Code Description RPMI_SUCCESS RPMI implementation ID returned successfully. Other errors [table_error_codes]
1	IMPL_ID	uint32	Implementation ID

Service: BASE_GET_SPEC_VERSION (SERVICE_ID: 0x04)

This service is used to get the implemented RPMI specification version. The version returned is a 32-bit composite number containing the MAJOR and MINOR version numbers.

Table 10. Request Data

NA

Table 11. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return error code Error Code Description RPMI_SUCCESS RPMI specification version returned successfully. Other errors [table_error_codes]
1	SPEC_VERSION	uint32	RPMI specification version Bits Description [31:16] MAJOR number [15:0] MINOR number

Service: BASE_GET_PLATFORM_INFO (SERVICE_ID: 0x05)

This service is used to get additional platform information if available.

Table 12. Request Data

NA

Table 13. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return error code Error Code Description RPMI_SUCCESS Platform information returned successfully. Other errors [table_error_codes]
1	PLATFORM_ID_LEN	uint32	Platform Identifier field length in bytes.
2	PLATFORM_ID	uint8[PLATFORM_ID_LEN]	Platform Identifier Up to PLATFORM_ID_LEN bytes NULL terminated ASCII string. The use and interpretation of this field is implementation-defined. It can be used to convey details such as the vendor ID, vendor name, specific product model, revision, or configuration of the hardware.

Service: BASE_PROBE_SERVICE_GROUP (SERVICE_ID: 0x06)

This service is used to probe the implementation of a service group and to obtain the implemented service group version. The service group version is a 32-bit composite number containing the MAJOR and MINOR numbers.

If the service group is successfully probed then the implemented service group version is returned in the SERVICE_GROUP_VERSION field. Otherwise it returns 0.

Table 14. Request Data

Word	Name	Type	Description
0	SERVICEGROUP_ID	uint32	Service group ID

Table 15. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return error code Error Code Description RPMI_SUCCESS Service probed successfully. Other errors [table_error_codes]
1	SERVICE_GROUP_VERSION	uint32	Service group version. Bits Description [31:16] MAJOR number [15:0] MINOR number

Service: BASE_GET_ATTRIBUTES (SERVICE_ID: 0x07)

This service is used to discover additional features supported by the BASE service group.

Table 16. Request Data

NA

Table 17. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return error code Error Code Description RPMI_SUCCESS Attributes returned successfully. Other errors [table_error_codes]
1	FLAGS0	uint32	Bits Description [31:3] Reserved, must be initialized to 0. [2] RPMI context privilege level. 0b1: M-mode 0b0: S-mode [1] EVENT_NOTIFICATION 0b1: Supported 0b0: Not supported [0] MSI 0b1: Supported 0b0: Not supported
2	FLAGS1	uint32	Reserved, must be initialized to 0.
3	FLAGS2	uint32	Reserved, must be initialized to 0.
4	FLAGS3	uint32	Reserved, must be initialized to 0.

Service: BASE_SET_MSI (SERVICE_ID: 0x08)

This service is used to configure the MSI address and data which the platform microcontroller can use as a doorbell to the application processor. The application processor must first discover the MSI support via BASE_GET_ATTRIBUTES service.

If the MSI support is not present then this service will be ignored with appropriate STATUS returned.

The platform microcontroller will enable MSI only if support is present and this service configures MSI address and data successfully.

Note	If the platform supports PLIC, the platform need to provide a MMIO register to inject an edge-triggered interrupt.

Note

The platform microcontroller can use MSI for both sending the MSI directly or injecting wired interrupt in the application processor. If the MSI target address is IMSIC, then the application processor will take MSI whereas if the MSI target address is setipnum of the APLIC then the application processor will take the wired interrupt.

Table 18. Request Data

Word	Name	Type	Description
0	MSI_ADDRESS_LOW	uint32	Lower 32-bit of the MSI address.
1	MSI_ADDRESS_HIGH	uint32	Upper 32-bit of the MSI address.
2	MSI_DATA	uint32	32-bit MSI data

Table 19. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return error code Error Code Description RPMI_SUCCESS MSI address and data are configured successfully. RPMI_ERR_NOT_SUPPORTED MSI is not supported. RPMI_ERR_INVALID_ADDR MSI address is not 4-byte aligned. Other errors [table_error_codes]