Checksum (Word 3Fh); Iba Capabilities - Intel 8 LAN Information Manual

1.4.23.4 IBA Capabilities (Word 33h)
Word 33h is used to enumerate the boot technologies that have been programmed into
the Flash. It is updated by IBA configuration tools and is not updated or read by IBA.
Table 21.

IBA Capabilities

Bit
15:14
13:5
4
3
2
1
0
1.4.24

Checksum (Word 3Fh)

The Checksum word (NVM bytes 7Eh and 7Fh) is used to ensure that the base NVM
image is valid. Its value should be calculated by adding all words (00h through 3Fh)/
bytes (00h-7Eh), including the Checksum word itself. The sum, including the
Checksum, should equal BABAh. The initial value before the values are added together
should be 0000h, and the carry bit should be ignored after each addition. If the OEM
does not desire to calculate the checksum, LAD programming tools and drivers will
detect if the checksum is incorrect and fix it in the image.
Note: The default image always has a checksum value of 0. The default image always has a
checksum value of 0b. The LAD programming tools (EEUPDATE or LANCONF) update
the checksum when the image is programmed.
22
Name
Signature. These bits must be set to 01b to indicate that this word has
SIG
been programmed by the agent or other configuration software.
Reserved Reserved for future use. All bits must be set to 0b.
SAN capability is present in Flash.
SAN 0b = The SAN capability is not present (default).
1b = The SAN capability is present.
EFI UNDI capability is present in Flash.
EFI 0b = The RPL code is not present (default).
1b = The RPL code is present.
Reserved Reserved. Must be set to 0b.
PXE/UNDI capability is present in Flash.
UNDI 1b = The PXE base code is present (default).
0b = The PXE base code is not present.
PXE base code is present in Flash.
BC 0b = The PXE base code is present.
1b = The PXE base code is not present (default).
NVM Information Guide—ICH8
Description