Intel Extensible Firmware Interface - Manual (Page 913)

32/64-Bit UNDI Specification
Version 1.10 12/01/02 E-47
E.4.3.2 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 started.
COMMAND_FAILED Command failed. StatCode field contains error code.
COMMAND_QUEUED Command has been queued.
INITIALIZE Command has been not executed or queued.
E.4.3.3 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 started.
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.
ALREADY_STARTED The UNDI is already started.