Intel Extensible Firmware Interface Specification page 400

Extensible Firmware Interface Specification
Table G-4. !PXE Structure Field Definitions (continued)
Identifier Value
S/W UNDI Fields
EntryPoint Varies
reserved Zero
BusTypeCnt Varies
BusType Varies
382
Description
S/W UNDI API entry point address. This is either a virtual address or an offset
from the start of the !PXE structure. Protocol drivers will push the 64-bit virtual
address of a CDB on the stack and then call the UNDI API entry point. When
control is returned to the protocol driver, the protocol driver must remove the
address of the CDB from the stack.
Reserved for future use.
This field is the count of four byte BusType entries in the next field.
This field defines the type of bus S/W UNDI is written to support:
"PCIR", "PCCR", "USBR" or "1394". This field is formatted like the Signature
field. If the S/W UNDI supports more than one BusType there will be more
than one BusType identifier in this field.
12/12/00 Version 1.02