Bus Entries; Bus Entry; Bus Type String Values - Intel MultiProcessor Specification

MultiProcessor Specification

4.3.2 Bus Entries

Bus entries identify the kinds of buses in the system. Because there may be more than one bus in a
system, each bus is assigned a unique bus ID number by the BIOS. The bus ID number is used by
the operating system to associate interrupt lines with specific buses. Figure 4-5 shows the format
of a bus entry, and Table 4-7 explains the fields of each entry.
31
31
Table 4-7. Bus Entry Fields
Field
ENTRY TYPE
BUS ID
BUS TYPE
STRING
4-10
24 23
BUS TYPE STRING
24 23
Figure 4-5. Bus Entry
Offset Length
(in bytes) (in bits) Description
0 8 Entry type 1 identifies a bus entry.
1 8 An integer that identifies the bus entry. The BIOS assigns
identifiers sequentially, starting at zero.
2 48 A string that identifies the type of bus. Refer to Table 4-8 for
values. These are 6-character ASCII (blank-filled) strings
used by the MP specification.
16 15 8 7
ENTRY TYPE
BUS ID
1
16 15 8 7
0
04H
00H
0
Version 1.4