Chapter 5: Troubleshooting

POST Code Listing (AMI Motherboard only)

Uncompressed Initialization Codes

The following runtime checkpoint codes are listed in order of execution. These codes are uncompressed in F0000h shadow RAM.

Checkpoint

 

Code

Description

03h

The NMI is disabled. Next, checking for a soft reset or a power on condition.

05h

The BIOS stack has been built. Next, disabling cache memory.

06h

Uncompressing the POST code next.

07h

Next, initializing the CPU and the CPU data area.

08h

The CMOS checksum calculation is done next.

0Ah

The CMOS checksum calculation is done. Initializing the CMOS status register for date and time

 

next.

0Bh

The CMOS status register is initialized. Next, performing any required initialization before the

 

keyboard BAT command is issued.

0Ch

The keyboard controller input buffer is free. Next, issuing the BAT command to the keyboard

 

controller.

0Eh

The keyboard controller BAT command result has been verified. Next, performing any necessary

 

initialization after the keyboard controller BAT command test.

0Fh

The initialization after the keyboard controller BAT command test is done. The keyboard command

 

byte is written next.

10h

The keyboard controller command byte is written. Next, issuing the Pin 23 and 24 blocking and

 

unblocking command.

11h

Next, checking if keys were pressed during power on. Initializing CMOS RAM if the Initialize CMOS

 

RAM in every boot AMIBIOS POST option was set in AMIBCP or the key was pressed.

12h

Next, disabling DMA controllers 1 and 2 and interrupt controllers 1 and 2.

13h

The video display has been disabled. Port B has been initialized. Next, initializing the chipset.

14h

The 8254 timer set will begin next.

19h

The 8254 timer test is over. Starting the memory refresh test next.

1Ah

The memory refresh line is toggling. Checking the 15 second on/off time next.

23h

Reading the 8042 input port and disabling the MEGAKEY Green PC feature next. Making the BIOS

 

code segment writable and performing any necessary configuration before initializing the

 

interrupt vectors.

24h

The configuration required before interrupt vector initialization has completed. Interrupt vector

 

initialization is about to begin.

25h

Interrupt vector initialization is done. Clearing the password if the POST DIAG switch is on.

27h

Any initialization before setting video mode will be done next.

28h

Initialization before setting the video mode is complete. Configuring the monochrome mode and

 

color settings next.

2Ah

Bus initialization system, static, output devices will be done next, if present.

2Bh

Passing control to the video ROM to perform any required configuration before the video ROM test.

2Ch

All necessary processing before passing control to the video ROM is done. Looking for the video

 

ROM next and passing control to it.

2Dh

The video ROM has returned control to BIOS POST. Performing any required processing after the

 

video ROM had control.

5–25

Page 102
Image 102
Agilent Technologies 45A Next, 0Bh, Keyboard BAT command is issued, 0Ch, Controller, 0Eh, 0Fh, Byte is written next, 10h