Post Code Reference Tables

These tables describe the POST codes and components of the POST process.

Post Code Range

Code	POST Routine Description

02h	Verify Real Mode

03h	Disable Non-Maskable Interrupt (NMI)

04h	Get CPU type

06h	Initialize system hardware

08h	Initialize chipset with initial POST values

09h	Set IN POST flag

0Ah	Initialize CPU registers

0Bh	Enable CPU cache

0Ch	Initialize caches to initial POST values

0Eh	Initialize USB component

Code	Beeps	POST Routine Description

0Fh		Initialize the local bus IDE

10h		Initialize Power Management

11h		Load alternate registers with initial POST values

12h		Restore CPU control word during warm boot

13h		Initialize PCI Bus Mastering devices

14h		Initialize keyboard controller

16h	1-2-2-3	BIOS ROM checksum

17h		Initialize cache before memory autosize

18h		8254 timer initialization

1Ah		8237 DMA controller initialization

1Ch		Reset Programmable Interrupt Controller

20h	1-3-1-1	Test DRAM refresh

22h	1-3-1-3	Test 8742 Keyboard Controller

24h		Set ES segment register to 4 GB

26h		Enable A20 line

28h		Autosize DRAM

29h		Initialize POST Memory Manager

2Ah		Clear 512 KB base RAM

2Ch	1-3-4-1	RAM failure on address line xxxx*

2Eh	1-3-4-3	RAM failure on data bits xxxx* of low byte of memory bus

2Fh		Enable cache before system BIOS shadow

30h	1-4-1-1	RAM failure on data bits xxxx* of high byte of memory bus

32h		Test CPU bus-clock frequency

33h		Initialize Phoenix Dispatch Manager

36h		Warm start shut down

Chapter 4

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