User`s guide

C-15
Error Messages and Recovery Information
IA–32
POST Codes
Meaning
0x0023 Read the 8042 input port and save switch setting, check for green KBC, and
disable the keyboard controller password.
Performing any necessary configuration before initializing the interrupt vec-
tors.
Next, checkpoint 0x0024.
0x0024 Perform any OEM specific initialization before interrupt vector initialization.
Interrupt vector initialization is about to begin.
Next, checkpoint 0x0025.
0x0025 Initializes interrupt vector table.
Test for POST diagnostics, Clear passwords if POST flag is set.
Indicate 25 video rows and monochrome display in BIOS data area.
Next, checkpoint 0X0027.
0x0027 Enable USB function/clock in chipset if necessary and if configurable, ini-
tialize USB, and perform any necessary chipset or OEM initialization.
Next, checkpoint 0x0028.
0x0028 Set monochrome and color mode video settings. Set 40 x 25 text / CGA col-
or display mode.
Next, checkpoint 0x0029.
0x0029 Jump to debugger hook, clear parity status (parity will be by IA64 part). Dia-
mond VGA option ROM bug fix.
Next, checkpoint 0x002A.
0x002A Initialize different buses through DIM module. See DIM Code
Checkpoints section of document for more information.
Initialize INT 40 vector to proper location (PCI SCSI adapter fix).
Initialize video.
Make F000 shadow RAM write enabled (ALWAYS READ/WRITE). If VGA
device was found and initialized by BIOS, go to checkpoint 0x002D, else
next checkpoint 0x002B.
Note that there
will be 15–bit
post codes in
this area.
These indicate
Device Initiali-
zation Manager
sub–codes.
The convention for the DIM POST codes is as follows:
Port 80 = 0x2A
Port 81 = DIM Function number | DI number
0x002B Passing control to the video ROM to perform any required configuration be-
fore the video ROM test.
Check to see if Option ROM scan should be performed. If no, go to check-
point 0x002D.
If yes, next checkpoint 0x002Ch.
0x002C Scan video ROM segment (C000) for option ROM. If found, pass control for
video initialization.
Next, checkpoint 0x002D.