Vol. 3A 9-45

PROCESSOR MANAGEMENT AND INITIALIZATION

Figure 9-8.  Microcode Update Write Operation Flow [1]

 

1

 

Valid Update

Header Version? 

Loader Revision Match

BIOS’s Loader?

 

Does Update Match A

CPU in The System 

Write Microcode Update

Does Update

Checksum Correctly? 

Yes

 

Yes

 

Yes

 

No

Return

CPU_NOT_PRESENT

No

Return

INVALID_HEADER

 

No

Return

INVALID_HEADER

 

No

Return

INVALID_HEADER_CS