Checkpoint | Description |
|
|
B1 | Save system context for ACPI. |
|
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00 | Passes control to OS Loader (typically INT19h). |
|
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OEM POST Error. This range is reserved for chipset vendors and 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.
NOTE: Checkpoints may differ between different platforms based on system configuration. Checkpoints may change due to vendor requirements, system chipset or option ROMs from
Checkpoint | 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 |
| 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. |
|
|
ACPI Runtime Checkpoints
Checkpoint | Description |
|
|
AC | First ASL check point. Indicates the system is running in ACPI mode. |
|
|
AA | System is running in APIC mode |
|
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01, 02, 03, 04, 05 | Entering sleep state S1, S2, S3, S4, or S5. |
|
|
10, 20, 30, 40, 50 | Waking from sleep state S1, S2, S3, S4, or S5 |
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Chapter 4 | 59 |