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

int main(int argc, char **argv)
{
	int i, j;
	char *resname;

	if (argc > 1 && !strcmp(argv[1], "wc"))
		resname = "/sys/bus/pci/devices/0000:01:00.1/resource0_wc";
	else
		resname = "/sys/bus/pci/devices/0000:01:00.1/resource0";

	int fd = open(resname, O_RDWR);
	if (fd == -1)
		return -1;

	void *ptr = mmap(NULL, 64*1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
	if (!ptr)
		return -1;

	volatile uint32_t *uptr = ptr;
	for (j = 0; j < 1024*1024; j++)
	for (i = 0; i < 16*1024; i++) {
		uptr[i] = 0;
	}
	munmap(ptr, 64*1024);
	close(fd);
}