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Vol. 3 9-43
PROCESSOR MANAGEMENT AND INITIALIZATION
The three platform ID bits, when read as a binary coded decimal (BCD) number, indi-
cate the bit position in the microcode update header’s processor flags field associated
with the installed processor. The processor flags in the 48-byte header and the
processor flags field associated with the extended processor signature structures
may have multiple bits set. Each set bit represents a different platform ID that the
update supports.
Register Name: IA32_PLATFORM_ID
MSR Address: 017H
Access: Read Only
IA32_PLATFORM_ID is a 64-bit register accessed only when referenced as a Qword through a
RDMSR instruction.
To validate the platform information, software may implement an algorithm similar to
the algorithms in Example 9-6.
Example 9-6. Pseudo Code Example of Processor Flags Test
Flag ← 1 << IA32_PLATFORM_ID[52:50]
If (Update.HeaderVersion == 00000001h)
{
If (Update.ProcessorFlags & Flag)
{
Load Update
Table 9-10. Processor Flags
Bit Descriptions
63:53 Reserved
52:50 Platform Id Bits (RO). The field gives information concerning the intended platform for
the processor. See also Table 9-7.
52 51 50
000Processor Flag 0
001Processor Flag 1
010Processor Flag 2
011Processor Flag 3
100Processor Flag 4
101Processor Flag 5
110Processor Flag 6
111Processor Flag 7
49:0 Reserved