Untitled

section .data
	
    	m1 	db 10,"Equivalent decimal number is: " 
        	m1len 	equ $- m1

            	newline db  10,10
                	newlinelength equ $-newline

                    	hex dw  0ffffh
                        	
                            section .bss

                            	buf	 resb 6
                                	buf_len	 equ $-buf
                                    	digitcount resb 1
                                        	ans	 resw 1
                                            	char_ans resb 4 

                                                %macro display  2

                                                	mov rax,1 
                                                    	mov rdi,1 
                                                        	mov rsi,%1 
                                                            	mov rdx,%2 
                                                                	syscall
                                                                    %endmacro




                                                                    section .text
                                                                    	global _start
                                                                        	_start:
                                                                            	
                                                                                	mov rax,[hex]
                                                                                    	mov	rbx,10		; rbx is loades with 10decimal , which is divisor

                                                                                        back:	xor	rdx,rdx		; make rdx=0
                                                                                        	div	rbx		; divide rdx:rax by rbx

                                                                                            	push	dx		; Remainder in dx is stored in stack
                                                                                                	inc	byte[digitcount]	; keep count of remainder digits

                                                                                                    	cmp	rax,0h		; compare quotient in rax with 0 
                                                                                                        	jne	back		; as long as, it is not zero , repeat
                                                                                                            				; else go to next instruction
                                                                                                                            	display	m1, m1len		; display message "Equivalent decimal number is: "

                                                                                                                                display_decimal:			; part of program which displays decimal number
                                                                                                                                	pop	dx		; take a BCD digit stored in stack & copy in dx
                                                                                                                                    	add	dl,30h		; possible BCD digits are 0-9 so add 30H only 
                                                                                                                                        	mov	[char_ans],dl 	; store character in char_ans

                                                                                                                                            	display	char_ans,1	; print on screen in reverse order ( last remainder is
                                                                                                                                                				; displayed first
                                                                                                                                                                	dec	byte[digitcount]	; repeat till all BCD digits are not displayed 
                                                                                                                                                                    	jnz	display_decimal
                                                                                                                                                                        
                                                                                                                                                                        	display newline , newlinelength 
                                                                                                                                                                            
                                                                                                                                                                            	mov rax, 60		; system call 60 is exit
                                                                                                                                                                                	mov rdi,0		
                                                                                                                                                                                    	syscall		)