@ ***********************************************************************
@ *									*
@ *                    Copy a NUL-terminated String                     *
@ *									*
@ ***********************************************************************

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

@ This program copies a NUL-terminated string from one location to
@ another.  The main features of this program are the use of a separate
@ module, "copy.s", for the actual copy-string function and the use of SWI
@ software interrupt instructions.  Please make sure that you read the
@ source code to "copy.s"!


	.text
	.global main	

@ ASCII codes
	.equ	NUL, 0		@ NUL is used for end of string
	.equ	LF, 10		@ Line Feed (end of line) character

@ External definitions (this section is optional but recommended)
	.extern	strcopy


main:
	push {lr}
	ldr	r0,=str_before	@ Print str_before to the console
	bl 	puts
	ldr	r0,=srcstr
	bl	puts
	ldr	r0, =dststr
	bl	puts
	ldr	r0,=dststr	@ R0 := address of destination string
	ldr	r1,=srcstr	@ R1 := address of source string
	bl	strcopy		@ Call the function "strcopy" (in "copy.s")
	ldr	r0,=str_after	@ Print str_after to the console
	bl	puts		@ then print the two strings (again)
	ldr	r0,=srcstr
	bl	puts
	ldr	r0, =dststr
	bl	puts
	pop {pc}



	.data			@ Read/write data follows
	.align			@ Align to a 32-bit boundary

srcstr:	.asciz	"First (source) string"
dststr:	.asciz	"Second (destination) string"

@ The source string "srcstr" could have been placed in the ".text"
@ section, as it is read-only.  Note that ".asciz" places a NUL character

	.data			@ Back to the data section (although these
				@ strings could have been left in ".text")

str_before:
	.asciz	"Before copying:"	@ Note: NOT ".asciz"!
str_after:
	.asciz	"After copying:"	@ The same, using C-style escapes
str_srcis:
	.asciz	"srcstr = \""		@ Using \" escape for double-quotes
str_dstis:
	.asciz	"\"\ndststr = \""
str_end:
	.asciz	"\"\n\n"

	.end