MS-9826 Mainboard
Post Code Checkpoints
The POST code checkpoints are the largest set of checkpoints during the BIOS preboot process. The following table describes the type of checkpoints that may occur during the POST portion of the BIOS:
Checkpoint | Description |
03 | 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 |
| “Wcomsflags”. |
04 | 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 |
| |
| Initializes data variables that are based on CMOS setup questions. |
| Initializes both the 8259 compatible PICs in the system. |
05 | Initializes the interrupt controlling hardware (generally PIC) and interrupt |
| vector table. |
06 | Do R/W test to |
| POSTINT1Ch handler. Enable |
| Traps INT1Ch vector to “POSTINT1ChHandlerBlock”. |
08 | 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 |
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 | Initializes different devices through DIM. |
2C | Initializes different devices. Detects and initializes the video adapter |
| installed in the system that have optional ROMs. |
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 test |
| information. |
37 | Displaying |
| any OEM specific information. |