zhanglongqi · January 31, 2020 07:15
diff --git a/bbb_eeprom.c b/bbb_eeprom.c
 /*
 * bbb_eeprom.c  Read Model & SerialNo from BeagleBone Black's EEPROM via i2c
 *
 * Compile with:
 *     cc bbb_eeprom.c -o bbb_eeprom
 *
 * Winston Smith <[email protected]>
 *
 * History:
 *   2014-05-01  Initial Implementation for FreeBSD
 *   2014-05-17  Port to Linux
 */

 #include <stdint.h>
 #include <sys/cdefs.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <fcntl.h>
 #include <sys/ioctl.h>
 #include <errno.h>
 #include <unistd.h>

 #if defined(__linux__)
 #	include <linux/i2c.h>
 #	include <linux/i2c-dev.h>
 #else
 #	include <dev/iicbus/iic.h>
 #endif

 #if defined(__linux__)
 #	define I2CRDWR I2C_RDWR
 #	define IIC_M_RD I2C_M_RD
 #	define IIC_M_WR 0
 #	define iic_rdwr_data i2c_rdwr_ioctl_data
 #	define iic_msg i2c_msg
 #	define slave addr
 #endif

 /*
 * Read data from an i2c device
 */
 int i2c_read(int fd, int slave, uint8_t *buffer, uint16_t offset, uint16_t len)
 {
 	struct iic_msg       msg[2];
 	struct iic_rdwr_data rdwr;

 	msg[0].slave = slave;
 	msg[0].flags = IIC_M_WR;
 	msg[0].len   = sizeof(offset);
 	msg[0].buf   = (uint8_t *)&offset;

 	msg[1].slave = slave;
 	msg[1].flags = IIC_M_RD;
 	msg[1].len   = len;
 	msg[1].buf   = buffer;

 	rdwr.nmsgs = 2;
 	rdwr.msgs  = msg;

 	if (ioctl(fd, I2CRDWR, &rdwr) < 0) {
 		return errno;
 	}

 	return 0;
 }

 /*
 * BeagleBone Black system EEPROM signature
 */
 uint8_t signature[] = { 0xAA, 0x55, 0x33, 0xEE };

 int main(int argc, char **argv)
 {
 	int fd;
 #if defined(__linux__)
 	char *dev = "/dev/i2c-0";
 #else
 	char *dev = "/dev/iic0";
 #endif
 	int     addr = 0x50;
 	uint8_t buffer[28];
 	char    work[32];
 	int     err;

 	if (argc > 1) {
 		dev = argv[1];
 	}

 	if ((fd = open(dev, O_RDWR)) < 0) {
 		perror("open failed");
 		exit(-1);
 	}

 	// For sanity checking!
 	memset((void *)buffer, '@', sizeof(buffer));

 	if ((err = i2c_read(fd, addr, buffer, 0, sizeof(buffer))) != 0) {
 		printf("i2c_read() failed with: %s (%d)\n", strerror(err), err);
 		exit(1);
 	}

 	close(fd);

 	printf("Read from slave %02X on %s: signature=%02X:%02X:%02X:%02X\n",
 	       addr,
 	       dev,
 	       buffer[0], buffer[1], buffer[2], buffer[3]);

 	if (memcmp((void *)buffer, (void *)signature, sizeof(signature)) != 0) {
 		printf("ERROR: EEPROM signature mismatched\n");
 		exit(1);
 	}

 	// Extract the 12 bytes allocated to the model
 	strncpy(work, (char *)&buffer[4], 12);
 	work[12] = 0;
 	printf("Model:\t%s\n", work);

 	// Extract the 12 bytes allocated to the serial number
 	strncpy(work, (char *)&buffer[16], 12);
 	work[12] = 0;
 	printf("Serial:\t%s\n", work);

 	exit(0);
 }
diff --git a/debian.md b/debian.md
diff --git a/u-boot.md b/u-boot.md
	/*
	* bbb_eeprom.c Read Model & SerialNo from BeagleBone Black's EEPROM via i2c
	*
	* Compile with:
	* cc bbb_eeprom.c -o bbb_eeprom
	*
	* Winston Smith <[email protected]>
	*
	* History:
	* 2014-05-01 Initial Implementation for FreeBSD
	* 2014-05-17 Port to Linux
	*/

	#include <stdint.h>
	#include <sys/cdefs.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <fcntl.h>
	#include <sys/ioctl.h>
	#include <errno.h>
	#include <unistd.h>

	#if defined(__linux__)
	# include <linux/i2c.h>
	# include <linux/i2c-dev.h>
	#else
	# include <dev/iicbus/iic.h>
	#endif

	#if defined(__linux__)
	# define I2CRDWR I2C_RDWR
	# define IIC_M_RD I2C_M_RD
	# define IIC_M_WR 0
	# define iic_rdwr_data i2c_rdwr_ioctl_data
	# define iic_msg i2c_msg
	# define slave addr
	#endif

	/*
	* Read data from an i2c device
	*/
	int i2c_read(int fd, int slave, uint8_t *buffer, uint16_t offset, uint16_t len)
	{
	struct iic_msg msg[2];
	struct iic_rdwr_data rdwr;

	msg[0].slave = slave;
	msg[0].flags = IIC_M_WR;
	msg[0].len = sizeof(offset);
	msg[0].buf = (uint8_t *)&offset;

	msg[1].slave = slave;
	msg[1].flags = IIC_M_RD;
	msg[1].len = len;
	msg[1].buf = buffer;

	rdwr.nmsgs = 2;
	rdwr.msgs = msg;

	if (ioctl(fd, I2CRDWR, &rdwr) < 0) {
	return errno;
	}

	return 0;
	}

	/*
	* BeagleBone Black system EEPROM signature
	*/
	uint8_t signature[] = { 0xAA, 0x55, 0x33, 0xEE };

	int main(int argc, char **argv)
	{
	int fd;
	#if defined(__linux__)
	char *dev = "/dev/i2c-0";
	#else
	char *dev = "/dev/iic0";
	#endif
	int addr = 0x50;
	uint8_t buffer[28];
	char work[32];
	int err;

	if (argc > 1) {
	dev = argv[1];
	}

	if ((fd = open(dev, O_RDWR)) < 0) {
	perror("open failed");
	exit(-1);
	}

	// For sanity checking!
	memset((void *)buffer, '@', sizeof(buffer));

	if ((err = i2c_read(fd, addr, buffer, 0, sizeof(buffer))) != 0) {
	printf("i2c_read() failed with: %s (%d)\n", strerror(err), err);
	exit(1);
	}

	close(fd);

	printf("Read from slave %02X on %s: signature=%02X:%02X:%02X:%02X\n",
	addr,
	dev,
	buffer[0], buffer[1], buffer[2], buffer[3]);

	if (memcmp((void )buffer, (void )signature, sizeof(signature)) != 0) {
	printf("ERROR: EEPROM signature mismatched\n");
	exit(1);
	}

	// Extract the 12 bytes allocated to the model
	strncpy(work, (char *)&buffer[4], 12);
	work[12] = 0;
	printf("Model:\t%s\n", work);

	// Extract the 12 bytes allocated to the serial number
	strncpy(work, (char *)&buffer[16], 12);
	work[12] = 0;
	printf("Serial:\t%s\n", work);

	exit(0);
	}