ARM汇编实现 for循环、strcmp、 调用printf打印字符串示例

utils.S （实现for循环、strcmp）

AREA FIRE, CODE, READONLY EXPORT for EXPORT strcmp_asm for PUSH {LR} FOR_LOOP BLX R0 SUBS R1, R1, #0x1 BNE FOR_LOOP POP {LR} BX LR strcmp_asm LDRB R2, [R0], #1 LDRB R3, [R1], #1 CMP R2, #0 CMPNE R3, #0 BEQ return CMP R2, R3 BEQ strcmp_asm return SUB R0, R2, R3 MOV PC, LR END

clac.S (下面为什么写“PRESERVE8”？ https://blog.csdn.net/heyustudent/article/details/39206155)

PRESERVE8 AREA CLAC, CODE, READONLY EXPORT asm_add IMPORT for IMPORT strcmp_asm IMPORT _printf ANONYMOUS_FIRE DCB "无名之火-_-!!", 0 ANONYMOUS_FIRE2 DCB "无名之火-_-!!", 0 asm_test PROC NOP BX LR ENDP asm_printf STMFD SP!, {LR} BL _printf LDMFD SP!, {PC} asm_add PROC STMFD SP!, {LR} LDR R0, =asm_test MOV R1, #0x3 ;BL for LDR R0, =ANONYMOUS_FIRE ;BL asm_printf BL _printf ;在ARM 里调用printf LDR R1, =ANONYMOUS_FIRE2 BL strcmp_asm ;BX LR LDMFD SP!, {R1} MOV PC, R1 ENDP END

main.c

#include<stdio.h> #include<stdlib.h> #include<stdint.h> extern int asm_add(int, int); int main(int argc, char* argv[]){ int a = 13; int b = 2; int result = asm_add(a, b); printf("hello, arm7 ! result=%d", result); return 0; }

输出：无名之火-_-!!hello, arm7 ! result=26

 

参考：

https://blog.csdn.net/denlee/article/details/2445810?utm_source=blogxgwz9

https://blog.csdn.net/heyustudent/article/details/39206155

https://wenku.baidu.com/view/a0306e974028915f804dc265.html