01 |
Disable the NMI and
test CPU registers |
02 |
Verify the BIOS ROM
checksum (32KB at F8000h) |
03 |
Initialize the keyboard
controller and CMOS RAM communication |
04 |
Disable the DMA and
PIT; test the CMOS RAM interrupt |
05 |
Reset the video controller |
06 |
Test the 8254 programmable
interrupt timer |
07 |
Test delta count timer
channel 2 (speaker) |
08 |
Test delta count timer
channel 1 (memory refresh) |
09 |
Test delta count timer
channel 0 (system timer) |
0A |
Test parity circuit
and turn on refresh |
0B |
Enable parity check
and test system timer |
0C |
Test refresh trace
link toggle |
0D |
Test refresh timing
synchronization |
10 |
Disable cache and shadow
memory; test the 64KB base memory |
11 |
Perform 64KB memory
read/write test |
12 |
Initialize interrupt
vector table in lower 1KB of RAM |
14 |
Test CMOS RAM shutdown
register...disable DMA and interrupt controllers |
15 |
Test CMOS RAM battery
and checksum |
16 |
Test for floppy drive,
based on CMOS setup...initialize monochrome video |
17 |
Initialize CGA video |
18 |
Clear the parity status
(if any) |
19 |
Test for EGA/VGA video
BIOS at C0000h and pass control |
1A |
Return from video ROM |
1B |
Test primary video
adapter...test video memory |
1C |
Test secondary video
adapter...test video memory |
1D |
Compare CMOS settings
to video adapter |
1E |
Set video mode according
to CMOS settings |
20 |
Display CMOS RAM read/write
errors and halt |
21 |
Set cursor and call
interrupt 10 to display status message |
22 |
Display power on message;
"386 BIOS"; check if CPU speed is 25Mhz or 33Mhz |
23 |
Read new cursor position |
24 |
Display AMI copyright
message at the bottom of the screen |
25 |
Test shadow RAM |
F0 |
Shadow RAM test failed |
30 |
Ready to enter protected
mode |
31 |
Enter protected mode
(A20 gate) and enable timer interrupt (IRQ 0) |
32 |
Get memory size above
1MB |
33 |
Get memory size below
640KB |
34 |
Test memory above 1MB |
35 |
Test memory below 1MB |
37 |
Clear memory below
1MB |
38 |
Clear memory above
1MB |
39 |
Use CMOS shutdown byte
and return to real mode |
3A |
Test 64KB read/write |
3B |
Test RAM below 1MB
and show the area being tested |
3C |
Test RAM above 1MB
and show the area being tested |
3D |
RAM test complete OK |
3E |
Ready to return to
real mode |
3F |
Back in real mode |
40 |
Disable A20 gate |
41 |
Check for AMI copyright
message in ROM |
42 |
Display the AMI copyright
message, if found |
43 |
Test cache memory;
Clear <Esc> message |
4E |
Process shutdown 1;
Return to real mode |
4F |
Restore interrupt vectors
and data in BIOS RAM area |
50 |
Test DMA controller |
51 |
Initialize DMA controller |
52 |
Test the DMA controller
with patterns |
54 |
Test DMA controller
latches |
55 |
Initialize and enable
DMA controllers 1 and 2 |
56 |
Initialize 8259 programmable
interrupt controllers |
57 |
Test 8259 programmable
interrupt controllers and setup interrupt mask registers |
61 |
Check DDNIL status
bit and display message |
70 |
Perform keyboard (BAT)
basic assurance test |
71 |
Program keyboard to
AT type |
72 |
Disable keyboard and
initialize keyboard circular buffer |
73 |
Display message and
initialize floppy controller and drive |
74 |
Attempt to access the
floppy drive |
75 |
If the CMOS RAM is
good, check and initialize the hard disk controller and drive |
76 |
Attempt to access the
hard disk drive |
77 |
Shuffle and internal
error codes |
79 |
Check CMOS RAM battery
and checksum...clear parity status |
7A |
Compare size of base/extended
memory to CMOS information |
7B |
Unknown AMI function |
7C |
Display AMI copyright |
7D |
Set AT memory expansion
bit |
7E |
Verify the ROM contains
and AMI copyright |
7F |
Clear the <Del>
message from the display...check if <Del> was pressed |
80 |
Locate option ROM at
C800h to DE00h and pass control to any found |
81 |
Return from option
ROM and initialize timer and data area |
82 |
Setup parallel and
serial ports |
83 |
Test for math coprocessor |
84 |
Check if keyboard is
locked |
85 |
Display any soft error
messages |
86 |
Test for option ROM
at E0000h |
A0 |
Error found in 256KB
or 1MB RAM IC in lower 640KB |
A1 |
Base 64KB random access
and data pattern test (only in 386APR and Presto 386SX BIOS) |
A9 |
Initialize on board
VGA controller (Presto 386SX BIOS) |
B0 |
Error in 256KB RAM
IC in 640KB |
B1 |
Base 64KB random access
and data pattern test (only in Presto 386SX BIOS) |
E0 |
Return to real mode
and initialize base 64KB RAM (Presto) |
E1 |
Initialize 640KB RAM
(Presto) |
EF |
Configuration memory
error - can't find memory |
F0 |
Test shadow RAM from
04000h |
00 |
Call the interrupt
19 boot loader |