Award Bios 4.51PG Postcodes

Hex
Code

Name

Description

C0

Turn Off Chipset Cache

OEM Specific-Cache control

1

ProcessorTest1

Processor Status (1FLAGS) Verification. Tests the following processor status flags: carry, zero, sign, overflow, The BIOS sets each flag, verifies they are set, then turns each flag off and verifies it is off.

2

ProcessorTest2

Read/Write/Verify all CPU registers except SS, SP, and BP with data pattern FF and 00.

3

Initialize Chips

Disable NMI, PIE, AIE, UEI, SQWV
Disable video, parity checking, DMA
Reset math coprocessor
Clear all page registers, CMOS shutdown byte
Initialize timer 0, 1, and 2, including set EISA timer to a known state
Initialize DMA controllers 0 and 1
Initialize interrupt controllers 0 and 1
Initialize EISA extended registers.

4

Test Memory

Refresh Toggle

RAM must be periodically refreshed to keep the memory from decaying. This function ensures that the memory refresh function is working properly

5

Blankvideo, Initialize

keyboard

Keyboard controller initialization

6

Reserved

-

7

Test CMOS Interface and Battery Status

Verifies CMOS is working correctly,
detects bad battery.

BE

Chipset Default Initialization

Program chipset registers with power on BIOS defaults.

C1

Memory presence test

OEM Specific-Test to size on-board memory

C5

Early Shadow

OEM Specific-Early Shadow enable for fast boot.

C6

Cache presence test

External cache size detection

8

Setup low memory

Early chip set initialization
Memory presence test
OEM chip set routines
Clear low 64K of memory
Test first 64K memory

9

Early Cache Initialization

Cyrix CPU initialization
Cache initialization

A

Setup Interrupt Vector Table

Initialize first 120 interrupt vectors with SPURIOUS_INT_HDLR and initialize INT 00h-1Fh according to INT_TBL

B

Test CMOS RAM Checksum

Test CMOS RAM Checksum, if bad, or insert key pressed, load defaults.

C

Initialize keyboard

Detect type of keyboard controller (optional) Set NUM_LOCK status.

D

Initialize Video Interface

Detect CPU clock.
Read CMOS location 14h to find out type of video in use.
Detect and Initialize Video Adapter

E

Test Video Memory

Test video memory, write sign-on message to screen.
Setup shadow RAM - Enable shadow according to Setup.

F

Test DMA Controller 0

BIOS checksum test.
Keyboard detect and initialization

10

Test DMA Controller 1

-

11

Test DMA Page Registers

Test DMA Page Registers.

12-13

Reserved

-

14

Test Timer Counter 2

Test 8254 Timer 0 Counter 2.

15

Test 8259-1 Mask Bits

Verify 8259 Channel 1 masked interrupts by alternately turning off and on the interrupt lines.

16

Test 8259-2 Mask Bits

Verify 8259 Channel 2 masked Interrupts by alternately turning off and on the interrupt lines.

17

Test Stuck

8259's Interrupt Bits

Turn off interrupts then verify no interrupt mask register is on.

18

Test 8259 Interrupt Functionality

Force an interrupt and verify the interrupt occurred.

19

Test Stuck NMI Bits (Parity/IO Check)

Verify NMI can be cleared.

1A

Display CPU clock

1B-1E

Reserved

-

1F

Set EISA Mode

If EISA non-volatile memory checksum is good, execute EISA initialization. If not, execute ISA tests an clear EISA mode flag. Test EISA Configuration Memory Integrity (checksum & communication Interface).

20

Enable Slot 0

Initialize slot 0 (System Board).

21-2F

Enable Slots 1-15

Initialize slots 1 through 15.

30

Size Base and Extended Memory

Size base memory from 256K to 640K
and extended memory above 1MB.

31

Test Base and Extended Memory

Test base memory from 256K to 640K and extended memory above 1MB using various patterns.
NOTE: This test is skipped in EISA mode and can be skipped with ESC key in ISA mode

32

Test EISA Extended Memory

If EISA Mode flag is set then test EISA memory found in slots initialization. NOTE: This test is skipped in ISA mode and can be skipped with ESC key in EISA mode.

33-3B

Reserved

-

3C

Setup Enabled

-

3D

Initialize & Install Mouse

Detect if mouse is present, initialize mouse, install interrupt vectors.

3E

Setup Cache Controller

Initialize cache controller.

3F

Reserved

-

BF

Chipset Initialization

Program chipset registers with Setup values
Display virus protect disable or enable

40

Initialize Floppy Drive & Controller

Initialize floppy disk drive controller and any drives.

42

Initialize Hard Drive & Controller

initialize hard drive controller and any drives.

43

Detect & Initialize Serial/Parallel Ports

Initialize any serial and parallel ports (also game port).

44

Reserved

-

45

Detect & Initialize Math Coprocessor

Initialize math coprocessor.

46

Reserved

-

47

Reserved

-

48-4D

Reserved

-

4E

Manufacturing POST Loop or Display Messages

Reboot if Manufacturing POST Loop pin is set. Otherwise display any messages (i.e., any non-fatal errors that were detected during POST) and enter Setup.

4F

Security Check

Ask password security (optional).

50

Write CMOS

Write all CMOS values back to RAM and clear screen.

51

Pre-boot Enable

Enable parity checker
Enable NMI, Enable cache before boot.

52

Initialize Option ROMs

Initialize any option ROMs present from C8000h to EFFFFh. NOTE: When FSCAN option is enabled, ROMs initialize from C8000h to F7FFFh.

53

Initialize Time Value

Initialize time value in 40h: BIOS area.

60

Setup Virus Protect

Setup virus protect according to Setup

61

Set Boot Speed

Set system speed for boot

62

Setup NumLock

Setup NumLock status according to Setup

63

Boot Attempt

Set low stack Boot via INT 19h.

B0

Spurious

If interrupt occurs in protected mode.

B1

Unclaimed NMI

If unmasked NMI occurs, display
Press F1 to disable NMI, F2 reboot.

E1-EF

Setup Pages

E1- Page 1, E2 - Page 2, etc.

FF

Boot

-