Intel BLKDX79TO Port 80h Post Codes, Post Code Description Acpi S States, PEI Phase Before MRC

Intel Desktop Board DX79TO Product Guide

Table 18 lists the Port 80h POST codes in hexadecimal notation.

Table 18. Port 80h POST Codes

POST Code	Description
	ACPI S States
00	Entering S0 state, standard
01-05	Entering S1-S5 state
10, 20, 30,	Resuming from S1-S5 state
40, 50
	Security Phase (SEC)
08	Starting BIOS execution after CPU BIST
09	SPI prefetching and caching
0A, 0B	Load BSP/APS microcode
0C	Platform program base addresses
0D	Wake up all APS
0E	Initialize NEM
0F	Pass entry point of the PEI core
	PEI Phase Before MRC
11	Set bootmode, GPIO init
12	Early chipset register programming
13	Basic PCH init, discrete device init
14	LAN init
15	Exit early platform init driver
16	SMBUS driver init
17, 18	Entry/Exit to SMBUS execute read/write
19, 1A	Entry/Exit to CK505 programming
1B, 1C	Entry/Exit to PEI overclock programming
	MEC Memory Detection
21	MRC entry point
23	Reading SPD from memory DIMMs
24	Detecting presence of memory DIMMs
27	Configuring memory
28	Testing memory
29	Exit MRC driver
	PEI After MRC
2A, 2B	Start/finish programming MTRR settings

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