#include <stdio.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <stdio.h>
#include <stdint.h>

#define PAGE_SIZE 4096

int main(int argc, char *argv[])
{
	int fd;
	int *b;

	fd = open("/dev/dummy", O_RDWR);
	if (fd < 0) {
		perror("open");
		return -1;
	}

	b = mmap(NULL, PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd,
	    0xFFFFFFFFFFFFF000);
	if (b == NULL) {
		perror("mmap");
		return -1;
	}

	printf("%d\n", *b);
	return 0;
}