Hexadecimal Arithmetic Operations in NASM

Write a switch case driven X86/64 ALP to perform 64-bit hexadecimal arithmetic operations. 

%macro print 2			;Macro for printing 
	mov rax, 1		    ;rax = 1 for sys_write	
	mov rdi, 1		    ;unsigned int file descriptor
	mov rsi, %1		    ;Buffer address
	mov rdx, %2		    ;Buffer length
	syscall		        ;Makes system call
%endmacro

%macro input 2			;Macro for reading 
	mov rax, 0		    ;rax = 0 for sys_read
	mov rdi, 0		    ;unsigned int file descriptor
	mov rsi, %1		    ;Buffer address
	mov rdx, %2		    ;Buffer length
	syscall		        ;Makes system call
%endmacro

section .data			                ;For declaring initialized data
	
	mssg db "Write a switch case driven X86/64 ALP to perform 64-bit hexadecimal arithmetic operations."
	mssg_len:equ $ - mssg
					
	mssg_name db " Aman Thakur 3205 🚀"		;Initialising mssg_name 
	mssg_name_len: equ $-mssg_name	
			
	mssg_sel db "--> Select an option from the menu :"
	mssg_sel_len: equ $ - mssg_sel

	mssg_menu db "--> Menu : <-- -="" .bss="" .text="" 0="" 0fh="" 10="" 16="" 17="" 1="" 1st="" 2="" 2nd="" 31h="" 32="" 32h="" 33h="" 34h="" 35h="" 3="" 4="" 60="" 64="" 8="" 9="" :="" _start:="" _start="" add="" addition:="" addition="" aking="" alling="" ame="" and="" ascii_hex32="" ascii_hex64:="" ascii_hex64="" be="" bit="" bits="" by="" byte.="" byte="" call="" case_1:="" case_2:="" case_2="" case_3:="" case_3="" case_4:="" case_4="" case_5:="" case_5="" chars="" choice="" cld="" cmp="" code="" conversion="" ctual="" cx="" db="" declared="" declaring="" direction="" display64="" display="" div="" dividend="" divides="" division:="" division="" divisor="" double="" during="" eax="" ebx="" edx="" emainder="" entry="" equ="" equal="" err:="" eserving="" essage="" estination="" esult="" exit:="" exit="" first="" flag="" for="" form="" from="" fter="" gets="" given="" global="" got="" has="" hex1="" hex2="" hexadecimal="" hoosing="" in="" incremented.="" input.="" input="" instruction="" into="" invalid="" is="" it="" ivision="" je="" jmp="" jne="" last="" ld="" learing="" left="" linker="" making="" menu:="" menu="" messages="" mov="" moving="" movsb="" mssg0="" mssg0_len:="" mssg0_len="" mssg1="" mssg1_len:="" mssg1_len="" mssg2="" mssg2_len:="" mssg2_len="" mssg3="" mssg3_len:="" mssg3_len="" mssg4="" mssg4_len:="" mssg4_len="" mssg="" mssg_error="" mssg_error_len:equ="" mssg_error_len="" mssg_len="" mssg_menu="" mssg_menu_len:="" mssg_menu_len="" mssg_mul="" mssg_mul_len:="" mssg_mul_len="" mssg_name="" mssg_name_len="" mssg_quot="" mssg_quot_len:="" mssg_quot_len="" mssg_rem="" mssg_rem_len:="" mssg_rem_len="" mssg_sel="" mssg_sel_len="" mssg_sub="" mssg_sub_len:="" mssg_sub_len="" mssg_sum="" mssg_sum_len:="" mssg_sum_len="" mul="" multiplication:="" multiplication="" newline="" next:="" now="" nput="" nter="" num1="" num2="" number.="" nvalid="" of="" onverting="" operand.="" operand1.="" operand1="" operand2.="" operand2="" operand:="" operands="" operation="" oping="" option="" or="" otating="" ource="" oving="" point.="" points="" pop="" present.="" print="" printed="" printing="" procedure="" push="" quad="" quotient="" rax.="" rax="" rbx.="" rbx="" rcx="" rdi="" rdx:rax="" rdx="" registers.="" remainder="" reminder="" rep="" resb="" resd="" resq="" result="" ret="" rinting="" roblem="" rol="" roll="" rror="" rsi="" second="" section="" sking="" so="" space="" statement.="" stored="" sub="" substraction:="" substraction="" sustraction="" sys_exit.="" syscall="" tells="" temp="" that="" the="" then="" to="" toring="" ubstraction="" ubtracting="" ultiplication="" um="" uotient="" use="" user="" value="" variables.="" when="" will="" word="" xiting="" your=""> F0h
		mov al, [rsi]				            ;Assigning [rsi] to al
		
		cmp al, 2Fh 				            ;Checking For Error
		jbe err				                    ;Case: al < 30h (0)
		cmp al, 47h	
		jge err				                    ;Case: al > 46h  (F)
		cmp al, 39h				
		jle ELSE				                ;Case: al <= 39h (9), No Error
		cmp al, 40h				
		jle err				                    ;Case al > 39(9) and al < 41(A)
		
		ELSE:
							
		cmp al, 39h				                ;Here we convert ascii to hex
		jbe  sub30h				                ;If al <= 39h (9), subtract 30h
		sub al, 7h				                ;Else subtract 37h
		sub30h:
			sub al, 30h			                ;Subtracting 30h from al
		add bl, al				
		inc rsi				
		dec rcx				
	jnz next
	
	ret 						                ;Return


display64:
	mov rcx, 16					
	mov rsi, temp					            ;rsi points to len
	next1:	
		rol rbx, 4				                ;rotating by 4 bits to left
		mov al, bl				
		and al, 0Fh				                ;To get only last digit, eg. 5Ah & 0Fh = 0Ah
		cmp al, 9h				                ;Case : al <= 9h (9)
		jbe add30h				                ;If True add 30h
		add al, 7h				                ;Else add 37h

		add30h:
			add al, 30h			                ;Adding 30h to al
		mov [rsi], al				            ;Storing al in temp
		inc rsi				
		dec rcx				
	jnz next1
	
	print temp, 16					            ;Printing number in ascii
	ret						                    ;Return

ascii_hex32:
	mov rcx, 8  					
	mov rsi, num2					            ;rsi points to num1
	mov rbx, 0 					
	next3:						
		rol ebx, 4				                ;Rotating by 4 bits to left, 0Fh -> F0h
		mov al, [rsi]				            ;Assigning [rsi] to al
		
		cmp al, 2Fh 				            ;Checking For Error
		jbe err				                    ;Case: al < 30h (0)
		cmp al, 47h	
		jge err				                    ;Case: al > 46h  (F)
		cmp al, 39h				
		jle ELSE2				                ;Case: al <= 39h (9), No Error
		cmp al, 40h				
		jle err				                    ;Case al > 39(9) and al < 41(A)
		
		ELSE2:
							
		cmp al, 39h				                ;Here we convert ascii to hex
		jbe  Sub30h				                ;If al <= 39h (9), subtract 30h
		sub al, 7h				                ;Else subtract 37h
		Sub30h:
			sub al, 30h			                ;Subtracting 30h from al
		add bl, al				
		inc rsi				
		dec rcx				
	jnz next3
	
	ret 						                ;Return