bus error

//test.c
#include <stdio.h>
#include <stdlib.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>

int main(void)
{
	static volatile char *reg_mem;
  static int axs_mem_fd = -1;
  axs_mem_fd = open("/dev/mem", O_RDWR|O_SYNC);
    if (axs_mem_fd < 0) {
        perror("AXS: can't open /dev/mem");
        return NULL;
    }
    /* memory map */
  reg_mem =(volatile char*)mmap(
      (caddr_t)reg_mem,
      0x4,
      PROT_READ|PROT_WRITE,
      MAP_SHARED,
      axs_mem_fd,
      0x04600000
  );
	if(reg_mem[0]==0x10) printf("OK");
	else printf("sorry");
}
host:
ppc_6xx-gcc -o test test.c
target:
./test
Bus error

need help,thanks

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