Intel Extensible Firmware Interface - Manual (Page 914)

Extensible Firmware Interface Specification
E-48 12/01/02 Version 1.10
E.4.4 Stop
This command is used to change the UNDI operational state from started to stopped.
E.4.4.1 Issuing the Command
To issue a Stop command, create a CDB and fill it in as shows in the table below:
CDB Field How to initialize the CDB structure for a Stop command
OpCode PXE_OPCODE_STOP
OpFlags PXE_OPFLAGS_NOT_USED
CPBsize PXE_CPBSIZE_NOT_USED
DBsize PXE_DBSIZE_NOT_USED
CPBaddr PXE_CPBADDR_NOT_USED
DBaddr PXE_DBADDR_NOT_USED
StatCode PXE_STATCODE_INITIALIZE
StatFlags PXE_STATFLAGS_INITIALIZE
IFnum A valid interface number from zero to !PXE.IFcnt
Control Set as needed
E.4.4.2 Waiting for the Command to Execute
Monitor the upper two bits (14 & 15) in the CDB.StatFlags field. Until these bits change to
report PXE_STATFLAGS_COMMAND_COMPLETE or PXE_STATFLAGS_COMMAND_FAILED ,
the command has not been executed by the UNDI.
StatFlags Reason
COMMAND_COMPLETE Command completed successfully. UNDI is now stopped.
COMMAND_FAILED Command failed. StatCode field contains error code.
COMMAND_QUEUED Command has been queued.
INITIALIZE Command has not been executed or queued.
E.4.4.3 Checking Command Execution Results
After command execution completes, either successfully or not, the CDB.StatCode field
contains the result of the command execution.
StatCode Reason
SUCCESS Command completed successfully. UNDI is now stopped.
INVALID_CDB One of the CDB fields was not set correctly.
BUSY UNDI is already processing commands. Try again later.
QUEUE_FULL Command queue is full. Try again later.
NOT_STARTED The UNDI is not started.
NOT_SHUTDOWN The UNDI is initialized and must be shutdown before it can be stopped.