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D6
R
D7
R
D8
A
D9
A
DA
A
Bootblock Recovery Code Checkpoint
The Bootblock recovery code gets control when the BIOS determines that a BIOS recovery needs to occur
because the user has forced the update or the BIOS checksum is corrupt. The following table describes the
type of checkpoints that may occur during the Bootblock recovery portion of the BIOS:
Checkpoint
Diagnostic LED Decoder
G=Green, R=Red, A=Amber
MSB
E0
R
E9
A
EA
A
EB
A
EF
A
F0
R
F1
R
F2
R
F3
R
F5
R
FA
A
123
A
G
R
Both key sequence and OEM specific method is checked to
determine if BIOS recovery is forced. Main BIOS checksum is
tested. If BIOS recovery is necessary, control flows to checkpoint
E0. See Bootblock Recovery Code Checkpoints section of
document for more information.
A
G
A
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.
R
OFF
R
The Runtime module is uncompressed into memory. CPUID
information is stored in memory.
R
OFF
A
Store the Uncompressed pointer for future use in PMM. Copying
Main BIOS into memory. Leaves all RAM below 1MB Read-Write
including E000 and F000 shadow areas but closing SMRAM.
R
G
R
Restore CPUID value back into register. Give control to BIOS
POST (ExecutePOSTKernel). See POST Code Checkpoints
section of document for more information.
Table 19. Bootblock Recovery Code Checkpoint
LSB
R
R
OFF
Initialize the floppy controller in the super I/O. Some interrupt vectors
are initialized. DMA controller is initialized. 8259 interrupt controller is
initialized. L1 cache is enabled.
R
R
G
Set up floppy controller and data. Attempt to read from floppy.
Determine information about root directory of recovery media.
R
A
OFF
Enable ATAPI hardware. Attempt to read from ARMD and ATAPI CD-
ROM. Determine information about root directory of recovery media.
R
A
G
Disable ATAPI hardware. Jump back to checkpoint E9.
A
A
G
Read error occurred on media. Jump back to checkpoint EB.
R
R
R
Search for pre-defined recovery file name in root directory.
R
R
A
Recovery file not found.
R
A
R
Start reading FAT table and analyze FAT to find the clusters occupied
by the recovery file.
R
A
A
Start reading the recovery file cluster by cluster.
A
R
A
Disable L1 cache.
R
A
R
Check the validity of the recovery file configuration to the current
configuration of the flash part.
Description
Chapter 4
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