Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
Where the Error Log Address Range does reside in NVRAM, OSPM requires no platform support to
read persisted error records. OSPM can scan the Error Log Address Range on its own and retrieve
the error records it previously persisted.
18.5.2.3 Clearing
After OSPM has finished processing an error record, it will notify the platform by clearing the
record. This allows the platform to delete the record from the persistent store or mark it such that the
space is free and can be reused. The following steps are executed by OSPM to clear an error record:
1. Executes a BEGIN_ CLEAR_OPERATION action to notify the platform that a record clear
operation is beginning.
2. Executes a SET_RECORD_IDENTIFER action to inform the platform which error record is to
be cleared. This value must not be set to 0x0 (unspecified).
3. Executes an EXECUTE_OPERATION action to instruct the platform to begin the clear
operation.
4. Busy waits by continually executing CHECK_BUSY_STATUS action until FALSE is returned.
5. Executes a GET_COMMAND_STATUS action to determine the status of the clear operation.
6. Execute an END_OPERATION to notify the platform that the record read operation is
complete.
The platform carries out a clear request by performing the following steps:
1. Sets some internal state to indication that it is busy. OSPM polls by executing a
CHECK_BUSY_STATUS action until the operation is completed.
2. Using the record identifier supplied by OSPM through the SET_RECORD_IDENTIFIER
operation, determine which error record to clear. This value may not be 0x0 (unspecified).
3. Locate the specified error record on the persistent store.
4. Mark the record as free by updating the Attributes in its serialization header.
5. Update internal record count.
6. Clear internal busy state so when OS
7. PM executes CHECK_BUSY_STATUS, the result indicates that the operation is complete.
When the Error Log Address Range resides in NVRAM, the OS requires no platform support to
Clear error records.
18.5.2.4 Usage
This section describes several possible ways the error record serialization mechanism might be
implemented.
18.5.2.4.1 Error Log Address Range Resides in NVRAM
If the Error Log Address Range resides in NVRAM, then when OSPM writes a record into the
logging range, the record is automatically persistent and the busy bit can be cleared immediately. On
a subsequent boot, OSPM can read any persisted error records directly from the persistent store
range. The size of the persistent store, in this case, is expected to be enough for several error records.
740 April, 2015 Version 6.0