Vol. 3A 9-59

PROCESSOR MANAGEMENT AND INITIALIZATION
Figure 9-8. Microcode Update Write Operation Flow [1]
1
V
a
lid
U
p
d
ate
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
N
o
R
eturn
CPU_NOT_PRESENT
No
Retur n
INVALID_HEADER
N
o
Retur n
INVALID_HEADER
N
o
R
eturn
INVAL ID_HEADER_ CS