; Write at an address passed in register RSI an ASCIIZ string in hexadecimal
; format with a hyphen as a byte delimiter, obtained from a 48-bit MAC-address,
; passed in register RDI.

option prologue:none, epilogue:none
.code
putmacst proc
_putmacst proc
	SHRD	RAX,RDI,48	; Put MAC-address in the highest 6 bytes of RAX
	MOV	RDI,RSI		; Starting buffer address
	MOV	ECX,0AAAH	; Initialise the nibble counter
	.repeat
		ROL	RAX,4	; Shift the MAC-address left by 1 nibble
		AND	AL,0FH	; Isolate its highest nibble in AL
		ADD	AL,'0'	; Convert it to ASCII, assuming it's a digit
		.if (AL > '9')	; But if it's a letter, increase its ASCII-code
			ADD	AL,'A'-'9'-1
		.endif
		STOSB		; Write it into the string updating the address
		SHR	ECX,1	; An even nibble?
		.continue .if (!carry?); No, there is one more
		MOV	AL,'-'	; Yes, prepare the delimiter as the next char
		STOSB		; and write it into the string
	.until (zero?)		; Not the last nibble? Go to the next one
	MOV	BYTE PTR [RDI-1],CL; Replace the 6th excessive hyphen with a 0
	RET
_putmacst endp
putmacst endp
end