Nvidia MCP 78S User Manual page 57

OEM POST Error Checkpoints
Checkpoints from the range 61h to 70h are reserved for chipset vendors & system
manufacturers. The error associated with this value may be different from one
platform to the next.
DIM Code Checkpoints
The Device Initialization Manager (DIM) gets control at various times during BIOS
POST to initialize different system busses. The following table describes the main
checkpoints where the DIM module is accessed
Checkpoint
2A
38
While control is in the different functions, additional checkpoints are output to port
80h as a word value to identify the routines under execution. The low byte value
indicates the main POST Code Checkpoint. The high byte is divided into two nibbles
and contains two fields. The details of the high byte of these checkpoints are as
follows:
HIGH BYTE XY
The upper nibble 'X' indicates the function number that is being executed. 'X' can be
from 0 to 7.
0 = func#0, disable all devices on the BUS concerned.
1 = func#1, static devices initialization on the BUS concerned.
2 = func#2, output device initialization on the BUS concerned.
3 = func#3, input device initialization on the BUS concerned.
Initialize different buses and perform the following functions: Reset,
Detect, and Disable (function 0); Static Device Initialization (function 1);
Boot Output Device Initialization (function 2). Function 0 disables all
device nodes, PCI devices, and PnP ISA cards. It also assigns PCI bus
numbers. Function 1 initializes all static devices that include manual
configured onboard peripherals, memory and I/O decode windows in PCIPCI
bridges, and noncompliant PCI devices. Static resources are also
reserved. Function 2 searches for and initializes any PnP, PCI, or AGP
video devices.
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.
:
4
Description
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