Chassis Plans ATXP-875P, Техническое описание

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Appendix B: Flash Bios ATXP-875P – Technical Reference
68 Chassis Plans
Table B-4 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
Code
Description
2A 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 PCI-PCI bridges,
and noncompliant PCI devices. Static resources are also
reserved. Function 2 searches for and initializes any
PnP, PCI, or AGP video devices.
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.
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.
4 = func#4, IPL device initialization on the BUS concerned.
5 = func#5, general device initialization on the BUS concerned.
6 = func#6, error reporting for the BUS concerned.
7 = func#7, add-on ROM initialization for all BUSes.
8 = func#8, BBS ROM initialization for all BUSes.
The lower nibble 'Y' indicates the BUS on which the different routines are being executed. 'Y' can be from 0 to 5.
0 = Generic DIM (Device Initialization Manager).
1 = On-board System devices.
2 = ISA devices.
3 = EISA devices.
4 = ISA PnP devices.
5 = PCI devices.