Content originally posted in LPCWare by venkateshkuppan on Sun Apr 21 07:50:09 MST 2013
I am trying out a simple program for ARM-C inter-working. Here is the code:
#include<stdio.h>
#include<stdlib.h>
int Double(int a);
extern int Start(void);
int main(){
int result=0;
printf("in C main\n");
result=Start();
printf("result=%d\n",result);
return 0;
}
int Double(int a)
{
printf("inside double func_argument_value=%d\n",a);
return (a*2);
}
The assembly file goes as-
.syntax unified
.cpu cortex-m3
.thumb
.align
.global Start
.global Double
.thumb_func
Start:
mov r10,lr
mov r0,#42
bl Double
mov lr,r10
mov r2,r0
mov pc,lr
During debugging on LPC1769(embedded artists board), I get an hardfault error on the instruction " result=Start(). " I am trying to do an arm-C internetworking here. the lr value during the execution of the above the statement(result=Start()) is 0x0000029F, where the faulting instruction is,and the pc value is 0x0000029E. This is how I got the faulting instruction in r1
__asm("mrs r0,MSP\n"
"isb\n"
"ldr r1,[r0,#24]\n");
Can anybody please explain where I am going wrong? Any solution is appreciated. Thank you in advance.
