c调用汇编
//main.c
#include <stdio.h>

extern int myadd(int a, int b);

int main(void)
{
int a = 3;
int b = 5;
int c;
c = myadd(a, b);
printf("%d\n", c);
return 0;
}
//myadd.s
AREA MYADD, CODE, READONLY
;ENTRY
EXPORT myadd
myadd
ADD R2, R0, R1
MOV R0, R2
MOV R15, R14;MOV PC, LR
END

--------------------------
汇编调用c
//main.c
#include <stdio.h>

extern int fun(int a, int b);
int add(int a, int b)
{
return a+b;
}
int main(void)
{
int res;
int a = 3, b = 5;
res = fun(a, b);
printf("%d\n", res);
return 0;
}
//fun.s
AREA FUN ,CODE, READONLY
IMPORT add
EXPORT fun
fun
add r0, r0, #1
add r1, r1, #1
mov r8, r14
bl add
mov r5, r0
mov r14, r8
mov pc, r14
end
----------------------------------
内嵌汇编
//main.c
#include <stdio.h>
int main(void)
{

__asm 
{
mrs r5, CPSR
bic r5, r5, #0xf
orr r5, r5, #0x2
msr CPSR_cxsf, r5
}
printf("hello\n");
return 0;
}