Chapter 4 76Bootblock Recovery Code CheckpointCheckpointDiagnostic LED DecoderDescriptionG=Green, R=Red, A=AmberMSB LSBE0 R R R OFFInitialize the floppy controller in the super I/O. Some interrupt vectorsare initialized. DMA controller is initialized. 8259 interrupt controller isinitialized. L1 cache is enabled.E9 A R R G Set up floppy controller and data. Attempt to read from floppy.Determine information about root directory of recovery media.EA A R A OFF Enable ATAPI hardware. Attempt to read from ARMD and ATAPI CD-ROM. Determine information about root directory of recovery media.EB A R A G Disable ATAPI hardware. Jump back to checkpoint E9.EF A A A G Read error occurred on media. Jump back to checkpoint EB.F0 R R R R Search for pre-defined recovery file name in root directory.F1 R R R A Recovery file not found.F2 R R A R Start reading FAT table and analyze FAT to find the clusters occupiedby the recovery file.F3 R R A A Start reading the recovery file cluster by cluster.F5 R A R A Disable L1 cache.FA A R A R Check the validity of the recovery file configuration to the currentconfiguration of the flash part.FB A R A AMake flash write enabled through chipset and OEM specific method.Detect proper flash part. Verify that the found flash part size equalsthe recovery file size.F4 R A R R The recovery file size does not equal the found flash part size.FC A A R R Erase the flash part.FD A A R A Program the flash part.FF A A A AThe 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.
