 section .data
 msg db 10,"The maximum number from given array : ", 
 len equ $-msg 
 newline db 10,13 
 nlen equ $-newline 
 arr db 2h,54h,4h,5h,7h 
section .bss
 cnt resb 1 
 buff resb 16 
%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

created 1 year ago by Aditya Barve

Assembly Online Compiler

Write, Run & Share Assembly code online using OneCompiler's Assembly online compiler for free. It's one of the robust, feature-rich online compilers for Assembly language. Getting started with the OneCompiler's Assembly compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as Assembly and start coding.

About Assembly

Assembly language(asm) is a low-level programming language, where the language instructions will be more similar to machine code instructions.

Every assembler may have it's own assembly language designed for a specific computers or an operating system.

Assembly language requires less execution time and memory. It is more helful for direct hardware manipulation, real-time critical applications. It is used in device drivers, low-level embedded systems etc.

Syntax help

Assembly language usually consists of three sections,

Data section

To initialize variables and constants, buffer size these values doesn't change at runtime.
bss section

To declare variables
text section

_start specifies the starting of this section where the actually code is written.

Variables

There are various define directives to allocate space for variables for both initialized and uninitialized data.

1. To allocate storage space to Initialized data

Syntax

variable-name    define-directive    initial-value

Define Directive	Description	Allocated Space
DB	Define Byte	1 byte
DW	Define Word	2 bytes
DD	Define Doubleword	4 bytes
DQ	Define Quadword	8 bytes
DT	Define Ten Bytes	10 bytes

2. To allocate storage space to un-initialized data

Define Directive	Description
RESB	Reserve a Byte
RESW	Reserve a Word
RESD	Reserve a Doubleword
RESQ	Reserve a Quadword
REST	Reserve a Ten Bytes

Constants

Constants can be defined using

1. equ

To define numeric constants

CONSTANT_NAME EQU regular-exp or value

2. %assign

To define numeric constants.

%assign constant_name value

3. %define

To define numeric or string constants.

%define constant_name value

Loops

Loops are used to iterate a set of statements for a specific number of times.

mov ECX,n
L1:
;<loop body>
loop L1

where n specifies the no of times loops should iterate.

Procedures

Procedure is a sub-routine which contains set of statements. Usually procedures are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

procedure_name:
   ;procedure body
   ret