Ami Post Code - MSI IM-GM45-D Manual

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Bootblock Initialization Code Checkpoints
The Bootblock initialization code sets up the chipset, memory and other com-
ponents before system memory is available. The following table describes the
type of checkpoints that may occur during the bootblock initialization portion of
the BIOS:
Checkpoint Description
Early chipset initialization is done. Early super I/O initialization is done
Before D1
including RTC and keyboard controller. NMI is disabled.
Perform keyboard controller BAT test. Check if waking up from power
D1 management suspend state. Save power-on CPUID value in scratch
CMOS.
Go to flat mode with 4GB limit and GA20 enabled. Verify the bootblock
D0
checksum.
Disable CACHE before memory detection. Execute full memory sizing
D2
module. Verify that flat mode is enabled.
If memory sizing module not executed, start memory refresh and do mem-
D3 ory sizing in Bootblock code. Do additional chipset initialization. Re-en-
able CACHE. Verify that flat mode is enabled.
Test base 512KB memory. Adjust policies and cache first 8MB. Set
D4
stack.
Bootblock code is copied from ROM to lower system memory and control
D5
is given to it. BIOS now executes out of RAM.
Both key sequence and OEM specific method is checked to determine if
BIOS recovery is forced. Main BIOS checksum is tested. If BIOS recovery
D6
is necessary, control flows to checkpoint E0. See Bootblock Recovery
Code Checkpoints section of document for more information.
Restore CPUID value back into register. The Bootblock-Runtime interface
D7 module is moved to system memory and control is given to it. Determine
whether to execute serial flash.
The Runtime module is uncompressed into memory. CPUID information
D8
is stored in memory.
Store the Uncompressed pointer for future use in PMM. Copying Main
D9 BIOS into memory. Leaves all RAM below 1MB Read-Write including
E000 and F000 shadow areas but closing SMRAM.
Restore CPUID value back into register. Give control to BIOS POST (Ex-
DA ecutePOSTKernel). See POST Code Checkpoints section of document
for more information.
MS-9834
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