Arbor Technology EasyBoard-882E, Руководство пользователя

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Appendices
Appendix A. AMI BIOS Checkpoints
A.1. Bootblock Initialization Code Checkpoints
The Bootblock 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 bootblock initialization portion
of the BIOS (Note):
Checkpoint Description
Before D0
If boot block debugger is enabled, CPU cache-as-RAM functionality is
enabled at this point. Stack will be enabled from this point.
D0
Early Boot Strap Processor (BSP) initialization like microcode update,
frequency and other CPU critical initialization. Early chipset initialization is
done.
D1
Early super I/O initialization is done including RTC and keyboard controller.
Serial port is enabled at this point if needed for debugging. NMI is disabled.
Perform keyboard controller BAT test. Save power-on CPUID value in
scratch CMOS. Go to flat mode with 4GB limit and GA20 enabled.
D2 Verify the boot block checksum. System will hang here if checksum is bad.
D3
Disable CACHE before memory detection. Execute full memory sizing
module. If memory sizing module not executed, start memory refresh and
do memory sizing in Boot block code. Do additional chipset initialization.
Re-enable CACHE. Verify that flat mode is enabled.
D4 Test base 512KB memory. Adjust policies and cache first 8MB. Set stack.
D5
Bootblock code is copied from ROM to lower system memory and control is
given to it. BIOS now executes out of RAM. Copies compressed boot block
code to memory in right segments. Copies BIOS from ROM to RAM for
faster access. Performs main BIOS checksum and updates recovery status
accordingly.
D6
Both key sequence and OEM specific method is checked to determine
if BIOS recovery is forced. If BIOS recovery is necessary, control flows
to checkpoint E0. See Bootblock Recovery Code Checkpoints section of
document for more information.
D7
Restore CPUID value back into register. The Bootblock-Runtime interface
module is moved to system memory and control is given to it. Determine
whether to execute serial flash.