User`s manual

POST Code Checkpoints
The POST code checkpoints are the largest set of checkpoints during the BIOS
pre-boot process. The following table describes the type of checkpoints that may
occur during the POST portion of the BIOS:
Checkpoint Description
3
Disable NMI, Parity, video for EGA, and DMA controllers. Initialize BIOS,
POST, Runtime data area. Also initialize BIOS modules on POST entry and
GPNV area. Initialized CMOS as mentioned in the Kernel Variable
"wCMOSFlags."
4
Check CMOS diagnostic byte to determine if battery power is OK and CMOS
checksum is OK. Verify CMOS checksum manually by reading storage area.
If the CMOS checksum is bad, update CMOS with power-on default values
and clear passwords. Initialize status register A. Initializes data variables that
are based on CMOS setup questions. Initializes both the 8259 compatible
PICs in the system
5
Initializes the interrupt controlling hardware (generally PIC) and interrupt
vector table.
6
Do R/W test to CH-2 count reg. Initialize CH-0 as system timer. Install the
POSTINT1Ch handler. Enable IRQ-0 in PIC for system timer interrupt. Traps
INT1Ch vector to "POSTINT1ChHandlerBlock."
8
Initializes the CPU. The BAT test is being done on KBC. Program the
keyboard controller command byte is being done after Auto detection of
KB/MS using AMI KB-5.
C0 Early CPU Init Start -- Disable Cache - Init Local APIC
C1 Set up boot strap processor Information
C2 Set up boot strap processor for POST
C5 Enumerate and set up application processors
C6 Re-enable cache for boot strap processor
C7 Early CPU Init Exit
0A Initializes the 8042 compatible Key Board Controller.
0B Detects the presence of PS/2 mouse.
0C Detects the presence of Keyboard in KBC port.
0E
Testing and initialization of different Input Devices. Also, update the Kernel
Variables. Traps the INT09h vector, so that the POST INT09h handler gets
control for IRQ1. Uncompress all available language, BIOS logo, and Silent
logo modules.
13 Early POST initialization of chipset registers.
24 Uncompress and initialize any platform specific BIOS modules.
30 Initialize System Management Interrupt.
2A Initialize different buses and
p
erform the followin
g
functions: Reset
,
Detect
,
2C Initializes different devices. Detects and initializes the video ada
p
ter installed
2E Initializes all the output devices.
31
Allocate memory for ADM module and uncompress it. Give control to ADM
module for initialization. Initialize language and font modules for ADM.
Activate ADM module.
33
Initializes the silent boot module. Set the window for displaying text
information.
37
Displaying sign-on message, CPU information, setup key message, and any
OEM specific information.
38
Initialize different buses and perform the following functions: Boot Input
Device Initialization (function 3); IPL Device Initialization (function 4); General
Device Initialization (function 5). Function 3 searches for and configures PCI
input devices and detects if system has standard keyboard controller.
Function 4 searches for and configures all PnP and PCI boot devices.
Function 5 configures all onboard peripherals that are set to an automatic
configuration and configures all remaining PnP and PCI devices.
39 Initializes DMAC-1 & DMAC-2.
3A Initialize RTC date/time.
3B Test for total memory installed in the system. Also, Check for DEL or ESC
4
-
3