Chapter 4
60
POST Task Routines
The following is a list of the Test Point codes written to port 80h at the start of each routine, the beep codes
issued for terminal errors, and a description of the POST routine. Unless otherwise noted, these codes are
valid for PhoenixBIOS.
NOTE:
The following routines are sorted by their test point numbers assigned in the BIOS code. Their actual
oder as executed during POST can be quite different.
Code
Beeps
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 I/O component
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
38h
Shadow system BIOS ROM
3Ah
Autosize cache
Summary of Contents for Aspire 1800
Page 6: ...VI ...
Page 12: ...4 Chapter 1 Block Diagram ...
Page 13: ...Chapter 1 5 Mainboard Placement Top View Rear View ...
Page 75: ...67 Chapter 5 Clear CMOS ...
Page 77: ...69 Chapter 6 Exploded Diagram ...
Page 78: ...Chapter 6 70 ...
Page 84: ...76 HDD SHIELDING HDD SHIELDING 33 A29V5 003 HDD COVER HDD COVER 42 A29V5 005 ...
Page 97: ...89 Appendix C ...