44 lines
1.1 KiB
NASM
44 lines
1.1 KiB
NASM
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;;;
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; disk_load
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; ---------
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; Load disk sectors into memory.
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;
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; Parameters:
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; - dh: number of sectors to read
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disk_load:
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pusha
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push dx ; store `dx' to check if the appropriate number of
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; sectors were read later on.
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mov ah, 0x02 ; BIOS read routine
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mov al, dh ; read `dh' sectors
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mov ch, 0x00 ; select cylinder 0
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mov dh, 0x00 ; select head 0
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mov cl, 0x02 ; start reading from second sector (after the boot
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; sector)
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int 0x13 ; BIOS interrupt
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jc disk_load_error ; if `cf' flag has gone off then a read error has
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; occurred
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pop dx ; restore `dx'
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cmp dh, al ; were the appropriate amount of sectors read?
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jne disk_load_unexp ; if not then there was an error
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popa
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ret
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disk_load_error:
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mov bx, DISK_READ_ERROR ; print the error
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jmp disk_load_print_exit
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disk_load_unexp:
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mov bx, DISK_READ_UNEXP
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disk_load_print_exit:
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call print_string
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jmp $ ; lock due to failure
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DISK_READ_UNEXP:
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db "Unexpected amount of sectors read!",0
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DISK_READ_ERROR:
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db "Disk read error!",0
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