Intel IA-32 - Manual (Page 434)

9-60 Vol. 3A
PROCESSOR MANAGEMENT AND INITIALIZATION
Figure 9-9. Microcode Update Write Operation Flow [2]
Return
INVALID_REVISION
Yes
1
Update Revision Newer
Than NVRAM Update?
Update Pass
Authenticity Test?
Return
SECURITY_FAILURE
Yes
Update NMRAM Record
Return
SUCCESS
Update Matching CPU
Already In NVRAM?
Space Available in
NVRAM?
Yes
No
Return
STORAGE_FULL
Replacement
policy implemented?
No
No
No Yes Yes