4 BIOS overview

order in which the POST tests are performed

boot block recovery code check points

E0

OnBoard Floppy Controller (if any) is initialzed. To start base 512K memory test.

 

 

E1

To initialise interrupt vector table.

 

 

E2

To initialise DMA and interrupt controllers.

 

 

E6

To enable floppy and timer IRQ, enable internal cache.

 

 

ED

Initialize floppy drive.

 

 

EE

Start looking for a diskette in drive A: and read 1st sector of the diskette.

 

 

EF

Floppy read error.

 

 

F0

Start searching 'AMIBOOT.ROM' file in root directory.

 

 

F1

'AMIBOOT.ROM' file not present in root directory.

 

 

F2

Start reading FAT table and analyze FAT to find the clusters occupied by 'AMIBOOT.ROM' file..

 

 

F3

Start reading 'AMIBOOT.ROM' file cluster by cluster.

 

 

F4

'AMIBOOT.ROM' file not of proper size.

 

 

F5

Disable internal cache.

 

 

FB

Detect Flash type present.

 

 

FC

Erase Flash.

 

 

FD

Program Flash.

 

 

FF

Flash program successful. BIOS is going to restart.

 

 

runtime code is uncompressed in F000 shadow ram

03

NMI is Disabled. To check soft reset/power-on.

 

 

 

 

05

BIOS stack set. Going to disable Cache if any.

 

 

 

 

06

POST code to be uncompressed.

 

 

 

 

07

CPU init and CPU data area init to be done.

 

 

 

 

08

CMOS checksum calculation to be done next.

 

 

 

 

 

0B

Any initialization before keyboard BAT to be done next.

 

 

 

 

 

0C

KB controller I/B free. To issue the BAT command to keyboard controller.

 

 

 

 

 

0E

Any initialization after KB controller BAT to be done next.

 

 

 

 

 

0F

Keyboard command byte to be written.

 

 

 

 

10

Going to issue Pin-23,24 blocking/unblocking command.

 

 

 

 

 

 

 

 

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