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disk_read:
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push dx ; store dx on stack so that we can compare later
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mov ah, BIOS_DISK_READ ; specify function
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mov al, dh ; read dh amount of sectors
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mov ch, 0x00 ; CYLINDER
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mov dh, 0x00 ; HEAD
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mov cl, 0x02 ; SECTOR
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int BIOS_DISK_INT ; interrupt
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; Error checks
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jc read_error ; carry flag set -> error
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pop dx
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|
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cmp dh, al ; if dh != al then error
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jne sector_error
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ret
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|
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sector_error:
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|
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mov bx, sector_error_string
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|
|
call println
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|
read_error:
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; Inform the user
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|
|
mov bx, read_error_string
|
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|
|
call println
|
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|
|
; Print the error
|
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|
|
mov bx, error_code_string
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|
|
call print
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|
mov dh, ah
|
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|
|
|
call print_hex
|
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|
|
mov bx, [ASCII_END]
|
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|
|
call println
|
|
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|
|
|
|
jmp $
|
|
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|
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|
|
|
|
read_error_string: db ASCII_CARRIAGE_RETURN, ASCII_LINEBREAK, "ERROR! Disk read failed.", ASCII_END
|
|
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|
|
error_code_string: db "Error code: ", ASCII_END
|
|
|
|
|
sector_error_string: db "Invalid number of sectors read!", ASCII_END
|
