Checkpoint

Description

 

 

 

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.

 

 

D8

The Runtime module is uncompressed into memory. CPUID information is stored in

 

memory.

 

 

D9

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.

 

 

DA

Restore CPUID value back into register. Give control to BIOS POST

 

(ExecutePOSTKernel). See POST Code Checkpoints section of document for more

 

information.

 

 

 

Bootblock recovery code checkpoints

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

Description

 

 

 

E0

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.

 

 

E9

Set up floppy controller and data. Attempt to read from floppy.

 

 

EA

Enable ATAPI hardware. Attempt to read from ARMD and ATAPI CDROM.

 

 

EB

Disable ATAPI hardware. Jump back to checkpoint E9.

 

 

EF

Read error occurred on media. Jump back to checkpoint EB.

 

 

E9 no EA

Determine information about root directory of recovery media.

 

 

F0

Search for pre-defined recovery file name in root directory.

 

 

F1

Recovery file not found.

 

 

F2

Start reading FAT table and analyze FAT to find the clusters occupied by the recovery

 

file.

 

 

F3

Start reading the recovery file cluster by cluster.

 

 

F5

Disable L1 cache.

 

 

FA

Check the validity of the recovery file configuration to the current configuration of the

 

flash part.

 

 

FB

Make flash write enabled through chipset and OEM specific method. Detect proper

 

flash part. Verify that the found flash part size equals the recovery file size.

 

 

F4

The recovery file size does not equal the found flash part size.

 

 

FC

Erase the flash part.

 

 

FD

Program the flash part.

 

 

FF

The flash has been updated successfully. Make flash write disabled. Disable ATAPI

 

hardware. Restore CPUID value back into register. Give control to F000 ROM at

 

F000:FFF0h.

 

 

 

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Chapter 4

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Aspire Digital H342, H341 manual Bootblock recovery code checkpoints