demo1: 子程序，调用C函数

	AREA MfArm,CODE,READONLY

	ENTRY

	EXPORT main

	IMPORT strcmp



big

	DCB "hello world",0

small

	DCB "hello world",0



main

	MOV R0,#1

	MOV R1,#2

	

	BL ADD_SUM

	MOV R3,R0



	ADR R0,big

	ADR R1,small

	BL strcmp

	mov R0,#0



	B stop





ADD_SUM

	ADD R0,R0,R1

	BX LR

	

stop

	END

demo2:  C语言调用 ARM汇编

C代码：

#include<stdio.h>

#include<string.h>



extern void* _memcpy(void* dest,void* src, size_t size);

int main(void)

{

	char dest[100]={0};

	char* src = "www.gyarmy.com";

	_memcpy(dest,src,strlen(src)+1);

	

	return 0;

}

ARM代码：

;_memcpy

	AREA Mfcode,CODE,READONLY

	EXPORT _memcpy



_memcpy

	STMFD SP!,{R4,LR}

	mov r3,r0

	mov r7,r1

	

copy

	CMP r2,#0

	BLE exit

	LDRB r4,[r7]

	STRB r4,[r3]

	ADDS r7,r7,#1

	ADDS r3,r3,#1

	SUBS R2,R2,#1

	BEQ exit

	B copy



exit

	LDMFD SP!,{r4,PC}

	END

demo3