POST Code

Function

Phase

Component

 

 

 

 

0x1A

Initialize DMA command register with these settings:

LBT

Core

 

1. Memory to memory disabled 2. Channel 0 hold

 

 

 

address disabled 3. Controller enabled 4. Normal

 

 

 

timing 5. Fixed priority 6. Late write selection 7.

 

 

 

DREQ sense active 8. DACK sense active low.

 

 

 

 

 

 

0x22

Reset the keyboard.

LBT

Core

 

 

 

 

0x40

Test A20 line

LBT

Core

 

 

 

 

0x67

Quick initialization of all Application Processors in a

LBT

Core

 

multi-processor system

 

 

 

 

 

 

0x32

Compute CPU speed.

LBT

Core

 

 

 

 

0x69

Initialize the handler for SMM.

LBT

Core

 

 

 

 

0x6B

If CMOS is bad, load Custom Defaults from flash into

LBT

Core

 

CMOS. If successful, reboot.

 

 

 

 

 

 

0x3C

If CMOS is valid, load chipset registers with values

LBT

Core

 

from CMOS, otherwise load defaults and display

 

 

 

Setup prompt. If Auto Configuration is enabled,

 

 

 

always load the chipset registers with the Setup

 

 

 

defaults (Rel 6.0).

 

 

 

 

 

 

0x3D

Load alternate registers with CMOS values

LBT

Core

 

 

 

 

0x42

Initialize interrupt vectors 0 thru 77h

LBT

Core

 

 

 

 

0x46

Verify the ROM copyright notice

LBT

Core

 

 

 

 

0x45

Initialize all motherboard devices.

LBT

Core

 

 

 

 

0x49

1. Size the PCI bus topology and set bridge bus

LBT

Core

 

numbers. 2. Set the system max bus number. 3.

 

 

 

Write a 0 to the command register of every PCI

 

 

 

device. 4. Write a 0 to all 6 base registers in every

 

 

 

PCI device. 5. Write a -1 to the status register of

 

 

 

every PC

 

 

 

 

 

 

0xC6

Initialize note dock

LBT

Core

 

 

 

 

0xC5

PnPnd dual CMOS (optional)

LBT

Core

 

 

 

 

0x48

Verify that the equipment specified in the CMOS

LBT

Core

 

matches the hardware currently installed. If the

 

 

 

monitor type is set to 00 then a video ROM must

 

 

 

exist. If the monitor type is 1 or 2 set the video switch

 

 

 

to CGA. If monitor type 3, set the video switch to m

 

 

 

 

 

 

0xD1

Initialize BIOS stack

LBT

Core

 

 

 

 

0xD3

Setup E820h and WAD memory map

LBT

Core

 

 

 

 

0x24

Set segment-register addressability to 4 GB

LBT

Core

 

 

 

 

0xCC

Redirect Int 10h to enable target board to use a

LBT

Core

 

remote serial video (PICO BIOS).

 

 

 

 

 

 

0x8A

Initialize Extended BIOS Data Area and initialize the

LBT

Core

 

mouse.

 

 

 

 

 

 

0x9D

Initialize Security Engine.

LBT

Core

 

 

 

 

0x55

USB Initialization

LBT

Core

 

 

 

 

0x52

Verify keyboard reset.

LBT

Core

 

 

 

 

0x54

Initialize keystroke clicker if enabled in Setup.

LBT

Core

 

 

 

 

0x76

Check status bits for keyboard-related failures.

LBT

Core

 

Display error messages on the screen.

 

 

 

 

 

 

0x4A

Initialize all video adapters in system

LBT

Core

 

 

 

 

138

Chapter 4

Page 148
Image 148
Acer 4230 manual 0x1A Initialize DMA command register with these settings