22 lines
653 B
ArmAsm
22 lines
653 B
ArmAsm
global outb
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; outb - Send a byte to an I/O port.
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; stack: [esp + 8] The data byte
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; [esp + 4] The I/O port
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; [esp ] Return address
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outb:
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mov al, [esp + 8] ; Move the data to send into the AL register
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mov dx, [esp + 4] ; Move the address of the I/O port into the DX register
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out dx, al ; Send the data to the I/O port
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ret ; Return
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global inb
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; inb - Returns a byte from the give I/O port.
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; stack: [esp + 4] The address of the I/O port
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; [esp ] The return address
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inb:
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mov dx, [esp + 4] ; Move the address of the I/O port to the dx register.
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in al, dx ; Read a byte from the I/O port and store it in the al register
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ret
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