user.c

很好的mmap（）驱动函数的it is a good driver for mmap func

// Linux Device Driver Template/Skeleton with mmap
// Userspace test program

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

#define CASE1 1
#define CASE2 2
#define BUFSIZE 64*1024
//extern  void hello(void);
extern  global;
//#define USEASCII

main() {
	int i, fd, len, wlen, tmp, tmp2;
	char string[] = "Skeleton Kernel Module Test";
	char receive[128];
	int data, rdata;

	char * mptr;
	size_t size = BUFSIZE;
#ifdef USEASCII	
	printf("USEASCII\n");
	char buffer[BUFSIZE];
#else
	printf("NO  USEASCII\n");
	unsigned int buffer[BUFSIZE];
#endif
	printf("global=%d\n",global);
	hello();
	printf("global=%d\n",global);
	fd = open("/dev/skeleton", O_RDWR | O_SYNC);
	if( fd == -1) {
		printf("open error...\n");
		exit(0);
	}

	// test device write function
	wlen = strlen(string) + 1;
	len = write(fd, string, wlen);
	if( len == -1 ) {
		printf("write error...\n");
		exit(1);
	}
	printf("String '%s' written to /dev/skeleton\n", string);
	
	// test device read function
	len = read(fd, receive, 128);
	if( len == -1 ) {
		printf("read error...n");
		exit(1);
	}
	printf("String '%s' read from /dev/skeleton\n", receive);

	// test mmap
	mptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, fd, 0);
	if(mptr == MAP_FAILED) {
		printf("mmap() failed\n");
		exit(1);
	}
	// write something into the kernel device driver memory allocated by kmalloc
//	memcpy(mptr, "Hello World!", 13);
	// clear our local buffer
	memset(buffer, 0, size);
	// read from the kmalloc area in kernel space
	memcpy(buffer, mptr, size-1);

#ifdef USEASCII
	printf("mmap: '%s'\n", buffer);
#else
	tmp = sizeof(int);
	for( i = 0; i < (10 * tmp); i = i + tmp) {
		tmp2 = (unsigned int)buffer[i];
		printf("buffer[%d]=%d\n", i, tmp2);
	}
#endif

	// test ioctl
	data = 0x55555555;
	ioctl(fd, CASE1, &data);
	ioctl(fd, CASE2, &rdata);
	printf("IOCTL test: written: '%x' - received: '%x'\n", data, rdata);

	munmap(mptr, size);
	close(fd);
}