ARM测试demo

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