Справочник Пользователя для Intel 253668-032US

Vol. 3 9-53

PROCESSOR MANAGEMENT AND INITIALIZATION

Example 9-12. INT 15 DO42 Calling Program Pseudo-code

We must be in real mode

If the system is not in Real mode exit

// Detect presence of Genuine Intel processor(s) that can be updated

// using(CPUID)

If no Intel processors exist that can be updated exit

Detect the presence of the Intel microcode update extensions

If the BIOS fails the PresenceTestexit

If the APIC is enabled, see if any other processors are out there

Read IA32_APICBASE

If APIC enabled

{

Send Broadcast Message to all processors except self via APIC

Have all processors execute CPUID, record the Processor Signature

(i.e.,Extended Family, Extended Model, Type, Family, Model,

Stepping)

Have all processors read IA32_PLATFORM_ID[52:50], record Platform

Id Bits

If current processor cannot be updated

exit

}

Determine the number of unique update blocks needed for this system

NumBlocks = 0

For each processor

{

If ((this is a unique processor stepping) AND

(we have a unique update in the database for this processor))

{

Checksum the update from the database;

If Checksum fails

exit

NumBlocks

← NumBlocks + size of microcode update / 2048

}