ASSIGNMENT 4

section .data
msg db 10,"The maximum number from given array : ",
len equ $-msg newline db 10,13 nlen equ$-newline
arr dw 2h,54h,4h,5h,7h

section .bss
cnt resb 1
buff resb 16global _start

section .data
imsg db 10,'Enter the String : '
len1 equ $-imsg omsg db 10,'Length of Given String : ' len2 equ$-omsg
nl db 10
len_nl equ $-nl section .bss dispbuff resb 2 buf resb 50 buf_len equ$-buf
len resb 1

%macro print 2
mov rax, 1
mov rdi, 1
mov rsi, %1
mov rdx, %2
syscall
%endmacro
%macro accept 2
mov rax, 0
mov rbx, 0
mov rcx, %1
mov rdx, %2
syscall
%endmacro

%macro exit 0
mov rax, 60
mov rdi, 0
syscall
%endmacro

section .text
_start:
print imsg, len1 ;display input prompt msg
accept buf, buf_len
dec al ;Decrementing coubt for avoiding string termination character
mov [len], al ;Save Length
print omsg, len2 ;display output msg
mov bl, [len] ;Restore length
call display ;call display procedure
print nl, len_nl
exit

display:
	mov rdi, dispbuff	;point rdi to buffer
	mov rcx, 2		;load number of digits to display
	disp1:
		rol bl, 4	;rotate number to left by nibble
		mov dl, bl	;move lower byte in dl
		and dl, 0fh	;mask upper digit of byte in dl
		add dl, 30h	;add 30h to calculate ASCII code	
		cmp dl, 39h	;compare with 39h
		jbe skip	;if less than 39h skip adding 07
		add dl, 07h	;else add 07
	skip:
		mov [rdi], dl	;store ASCII code in buff
		inc rdi		;point to next byte
		loop disp1	;decrement count of digits to display
		
	print dispbuff, 2	;display max number
	ret
		

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

section .text
global _start
_start:
mov byte[cnt], 5
mov rsi, arr
mov al, 0

	lp:
		cmp al, [rsi]
		jg skip
		xchg al, [rsi]
	
	skip:
		inc rsi
		dec byte[cnt]
		jnz lp
		call disp
		
		print msg, len
		print buff, 16
		print newline, nlen
		
		mov rax, 60
		mov rdi, 0
		syscall
		
	disp:
		mov rbx, rax
		mov rdi, buff
		mov cx, 16
		up1:
			rol rbx, 04
			mov al, bl
			and al, 0fh
			cmp al, 09h
			jg add_37
			add al, 30h
			jmp skip1
		add_37:
			add al, 37h
		
	skip1:
		mov [rdi], al
		inc rdi
		dec cx
		jnz up1
	ret