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24 lines
581 B
NASM
24 lines
581 B
NASM
section .text
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global inb
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global outb
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; Read a byte from the specified port
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; Input: DX = port number
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; Output: AL = data read from the port
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inb:
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PUSH DX ; Preserve DX
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IN AL, DX ; Read from port
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POP DX ; Restore DX
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RET
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; Write a byte to the specified port
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; Input: DX = port number, AL = data to write
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outb:
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PUSH DX ; Preserve DX
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PUSH AX ; Preserve AX
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MOV DX, [ESP + 4] ; Get port number from stack
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MOV AL, [ESP + 6] ; Get data from stack
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OUT DX, AL ; Write to port
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POP AX ; Restore AX
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POP DX ; Restore DX
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RET |