Boot Block Recovery Code Checkpoints - Acer Aspire X1470 Service Manual

Checkpoint
D6
D7
D8
D9
DA

Boot Block Recovery Code Checkpoints

The boot block recovery code gets control when the BIOS determines that a BIOS recovery is required
because the user has forced the update or the BIOS checksum is corrupt. Refer to "BIOS Recovery" section
on page 77 for more information. The following table describes the type of checkpoints that may occur during
the boot block recovery portion of the BIOS.
Checkpoint
E0
E9
EA
EB
EF
E9 or EA
F0
F1
F2
F3
F5
FA
FB
F4
FC
FD
FF
Aspire AX1470 Service Guide
Description
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 the "Boot Block Recovery Code Checkpoints" section for more
information.
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.
The Runtime module is uncompressed into memory. CPUID information is stored in
memory.
Store the Uncompressed pointer for future use in PMM. Copying Main BIOS into memory.
Leaves all RAM below 1 MB Read-Write including E000 and F000 shadow areas but
closing SMRAM.
Restore CPUID value back into register. Give control to BIOS POST
(ExecutePOSTKernel). See the "POST Code Checkpoints" section for more information.
Description
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.
Set up floppy controller and data. Attempt to read from floppy.
Enable ATAPI hardware. Attempt to read from ARMD and ATAPI CDROM.
Disable ATAPI hardware. Jump back to checkpoint E9.
Read error occurred on media. Jump back to checkpoint EB.
Determine information about root directory of recovery media.
Search for pre-defined recovery file name in root directory.
Recovery file not found.
Start reading FAT table and analyze FAT to find the clusters occupied by the recovery file.
Start reading the recovery file cluster by cluster.
Disable L1 cache.
Check the validity of the recovery file configuration to the current configuration of the flash
part.
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.
The recovery file size does not equal the found flash part size.
Erase the flash part.
Program the flash part.
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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