IBM manual Image, A-4 ThinkPad 560/560E SMAPI BIOS

Header

Image

Systems

that

support

SMAPI

BIOS must provide the following header

image in the F000 segment system ROM area at the 16-byte

boundary. The

client

needs

to search and find this SMAPI

BIOS

header image

to

get

the

entry

point for

the

service.

Field

Offset

Length

Value

Signature

00h

4 bytes

'$SMB

'

(ASCII)

Version

(Major)

04h

Byte

01h

Version

(Minor)

05h

Byte

00h

Length

06h

Byte

20h

Checksum

07h

Byte

–

Information

Word

08h

Word

–

Reserved

1

0Ah

Word

–

Real mode 16-bit offset

to0Ch entry

Word

–

point

Real mode 16-bit code

segment0Eh

Word

–

address

Reserved

2

10h

Word

–

16-bit protected mode offset12h

to

Word

–

entry

point

16-bit protected mode code14h

Dword

–

segment

base address

32-bit protected mode offset18h

to

Dword

–

entry

point

32-bit protected mode code1Ch

Dword

–

segment

base address

Signature

ASCII Code'$SMB

'

is

stored

at

the top

of

the

header

image.

Version

(Major/Minor)

Indicates

the SMAPI

BIOS

version.

Length

The

length

of

the

header

image.

Checksum

Checksum

byte

area. The

client

verifies that this

header

image

is

valid by using this checksum; the client

should

check

all

header

image

bytes,

and

the

result will

be

zero

bytes.

A-4ThinkPad 560/560E SMAPI BIOS