SE7221BK1
-E
Technical Product Specification
66
Checkpoint
Description
7A
Initializes remaining option ROMs.
7C
Generate and write contents of ESCD in NVRam.
84
Log errors encountered during POST.
85
Display errors to the user and gets the user response for error.
87
Execute BIOS setup if needed / requested.
8C
Late POST initialization of chipset registers.
8D
Build ACPI tables (if ACPI is supported)
8E
Program the peripheral parameters. Enable/Disable NMI as selected
90
Late POST initialization of system management interrupt.
A0
Check boot password if installed.
A1
Clean-up work needed before booting to OS.
A2
Takes care of runtime image preparation for different BIOS modules. Fill the free area in F000h
segment with 0FFh. Initializes the Microsoft IRQ Routing Table. Prepares the runtime language
module. Disables the system configuration display if needed.
A4
Initialize runtime language module.
A7
Displays the system configuration screen if enabled. Initialize the CPU’s before boot, which
includes the programming of the MTRR’s.
A8
Prepare CPU for OS boot including final MTRR values.
A9
Wait for user input at config display if needed.
AA
Uninstall POST INT1Ch vector and INT09h vector. De-initializes the ADM module.
AB
Prepare BBS for Int 19 boot.
AC
End of POST initialization of chipset registers.
B1
Save system context for ACPI.
00
Passes control to OS Loader (typically INT19h).
9.7.3.2 Boot Block Initialization Code Checkpoints
The Boot Block initialization code sets up the chipset, memory and other components before
system memory is available. The following table describes the type of checkpoints that may
occur during the boot block initialization.
Table 73. Bootblock Initialization Code Checkpoints
Checkpoint
Description
Before D1
Early chipset initialization is done. Early super I/O initialization is done including RTC
and keyboard controller. NMI is disabled.
D1
Perform keyboard controller BAT test. Check if waking up from power management
suspend state. Save power-on CPUID value in scratch CMOS.
D0
Go to flat mode with 4GB limit and GA20 enabled. Verify the bootblock checksum.
D2
Disable CACHE before memory detection. Execute full memory sizing module. Verify
that flat mode is enabled.