; ***********************************************************************
; *									*
; *               A Simple ARM Assembly Language Program                *
; *									*
; ***********************************************************************

; Author:   John Zaitseff <J.Zaitseff@unsw.edu.au>
; Date:     9th September, 2002
; Version:  1.4

; This program contains a simple ARM assembly language program.  The main
; purpose of this is to show you what such a program looks like: in
; particular, what assembler directives are needed.


; Everything following a semicolon ";" is a comment and is ignored by the
; GNU Assembler.  That does not mean that you should do the same!

/* C-style comment syntax can also be used, if you so wish */


	.text			; Executable code follows this point.  All
				; actual code (ARM instructions) should
				; appear in the ".text" section.

	.global	_start		; "_start" is required by the GNU Linker to
				; let it know where the program starts.
				; It has to be explicitly declared "global
				; to the entire program".

_start:				; Entry point of our program.  By default,
				; "_start" marks the first instruction to
				; be executed.  It is also a good place to
				; put a breakpoint.

	mov	r0,#10		; Set up parameters into R0 and R1
	mov	r1,#8
	add	r2,r0,r1	; and perform R2 := R0 + R1

; You can modify the code above to teach yourself about the basic ARM
; arithmetic and logical instructions.  Try replacing the "add" with "sub"
; (subtract), "rsb" (reverse subtract), "mul" (multiply), "and" (boolean
; AND), "orr" (boolean OR), "eor" (boolean XOR) or "bic" (bit clear).

; You can also experiment with changing the parameters to other values.
; But be careful: the "mov" instruction is limited as to what values it
; can accept.  See page A5-6 of the ARM Architecture Reference Manual
; (page 222 of the PDF document) for more information.  The file
; "values.s" also deals with this issue.

exit:				; Label the exit portion of the program.
				; This label can be anything you like,
				; although using "exit" is a good convention.

	swi	0x11		; Terminate the program using a software
				; interrupt to the Monitor.

	.end			; Mark the end of the input file