board/freescale/common/sys_eeprom.c - platform/external/u-boot - Gitiles

 /*
  * Copyright 2006, 2008-2009 Freescale Semiconductor
  * York Sun (yorksun@freescale.com)
  * Haiying Wang (haiying.wang@freescale.com)
  * Timur Tabi (timur@freescale.com)
  *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; either version 2 of
  * the License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  * MA 02111-1307 USA
  */

 #include <common.h>
 #include <command.h>
 #include <i2c.h>
 #include <linux/ctype.h>

 #include "../common/eeprom.h"

 #if !defined(CONFIG_SYS_I2C_EEPROM_CCID) && !defined(CONFIG_SYS_I2C_EEPROM_NXID)
 #error "Please define either CONFIG_SYS_I2C_EEPROM_CCID or CONFIG_SYS_I2C_EEPROM_NXID"
 #endif

 #define MAX_NUM_PORTS	8	/* This value must be 8 as defined in doc */

 /**
  * static eeprom: EEPROM layout for CCID or NXID formats
  *
  * See application note AN3638 for details.
  */
 static struct __attribute__ ((__packed__)) eeprom {
 #ifdef CONFIG_SYS_I2C_EEPROM_CCID
 	u8 id[4];         /* 0x00 - 0x03 EEPROM Tag 'CCID' */
 	u8 major;         /* 0x04        Board revision, major */
 	u8 minor;         /* 0x05        Board revision, minor */
 	u8 sn[10];        /* 0x06 - 0x0F Serial Number*/
 	u8 errata[2];     /* 0x10 - 0x11 Errata Level */
 	u8 date[6];       /* 0x12 - 0x17 Build Date */
 	u8 res_0[40];     /* 0x18 - 0x3f Reserved */
 	u8 mac_count;     /* 0x40        Number of MAC addresses */
 	u8 mac_flag;      /* 0x41        MAC table flags */
 	u8 mac[MAX_NUM_PORTS][6];     /* 0x42 - 0x71 MAC addresses */
 	u32 crc;          /* 0x72        CRC32 checksum */
 #endif
 #ifdef CONFIG_SYS_I2C_EEPROM_NXID
 	u8 id[4];         /* 0x00 - 0x03 EEPROM Tag 'NXID' */
 	u8 sn[12];        /* 0x04 - 0x0F Serial Number */
 	u8 errata[5];     /* 0x10 - 0x14 Errata Level */
 	u8 date[6];       /* 0x15 - 0x1a Build Date */
 	u8 res_0;         /* 0x1b        Reserved */
 	u32 version;      /* 0x1c - 0x1f NXID Version */
 	u8 tempcal[8];    /* 0x20 - 0x27 Temperature Calibration Factors */
 	u8 tempcalsys[2]; /* 0x28 - 0x29 System Temperature Calibration Factors */
 	u8 tempcalflags;  /* 0x2a        Temperature Calibration Flags */
 	u8 res_1[21];     /* 0x2b - 0x3f Reserved */
 	u8 mac_count;     /* 0x40        Number of MAC addresses */
 	u8 mac_flag;      /* 0x41        MAC table flags */
 	u8 mac[MAX_NUM_PORTS][6];     /* 0x42 - 0x71 MAC addresses */
 	u32 crc;          /* 0x72        CRC32 checksum */
 #endif
 } e;

 /* Set to 1 if we've read EEPROM into memory */
 static int has_been_read = 0;

 #ifdef CONFIG_SYS_I2C_EEPROM_NXID
 /* Is this a valid NXID EEPROM? */
 #define is_valid ((e.id[0] == 'N') || (e.id[1] == 'X') || \
 		  (e.id[2] == 'I') || (e.id[3] == 'D'))
 #endif

 #ifdef CONFIG_SYS_I2C_EEPROM_CCID
 /* Is this a valid CCID EEPROM? */
 #define is_valid ((e.id[0] == 'C') || (e.id[1] == 'C') || \
 		  (e.id[2] == 'I') || (e.id[3] == 'D'))
 #endif

 /**
  * show_eeprom - display the contents of the EEPROM
  */
 static void show_eeprom(void)
 {
 	int i;
 	unsigned int crc;

 	/* EEPROM tag ID, either CCID or NXID */
 #ifdef CONFIG_SYS_I2C_EEPROM_NXID
 	printf("ID: %c%c%c%c v%u\n", e.id[0], e.id[1], e.id[2], e.id[3],
 		be32_to_cpu(e.version));
 #else
 	printf("ID: %c%c%c%c\n", e.id[0], e.id[1], e.id[2], e.id[3]);
 #endif

 	/* Serial number */
 	printf("SN: %s\n", e.sn);

 	/* Errata level. */
 #ifdef CONFIG_SYS_I2C_EEPROM_NXID
 	printf("Errata: %s\n", e.errata);
 #else
 	printf("Errata: %c%c\n",
 		e.errata[0] ? e.errata[0] : '.',
 		e.errata[1] ? e.errata[1] : '.');
 #endif

 	/* Build date, BCD date values, as YYMMDDhhmmss */
 	printf("Build date: 20%02x/%02x/%02x %02x:%02x:%02x %s\n",
 		e.date[0], e.date[1], e.date[2],
 		e.date[3] & 0x7F, e.date[4], e.date[5],
 		e.date[3] & 0x80 ? "PM" : "");

 	/* Show MAC addresses  */
 	for (i = 0; i < min(e.mac_count, MAX_NUM_PORTS); i++) {

 		u8 *p = e.mac[i];

 		printf("Eth%u: %02x:%02x:%02x:%02x:%02x:%02x\n", i,
 			p[0], p[1], p[2], p[3],	p[4], p[5]);
 	}

 	crc = crc32(0, (void *)&e, sizeof(e) - 4);

 	if (crc == be32_to_cpu(e.crc))
 		printf("CRC: %08x\n", be32_to_cpu(e.crc));
 	else
 		printf("CRC: %08x (should be %08x)\n",
 			be32_to_cpu(e.crc), crc);

 #ifdef DEBUG
 	printf("EEPROM dump: (0x%x bytes)\n", sizeof(e));
 	for (i = 0; i < sizeof(e); i++) {
 		if ((i % 16) == 0)
 			printf("%02X: ", i);
 		printf("%02X ", ((u8 *)&e)[i]);
 		if (((i % 16) == 15) || (i == sizeof(e) - 1))
 			printf("\n");
 	}
 #endif
 }

 /**
  * read_eeprom - read the EEPROM into memory
  */
 static int read_eeprom(void)
 {
 	int ret;
 #ifdef CONFIG_SYS_EEPROM_BUS_NUM
 	unsigned int bus;
 #endif

 	if (has_been_read)
 		return 0;

 #ifdef CONFIG_SYS_EEPROM_BUS_NUM
 	bus = i2c_get_bus_num();
 	i2c_set_bus_num(CONFIG_SYS_EEPROM_BUS_NUM);
 #endif

 	ret = i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, 0, CONFIG_SYS_I2C_EEPROM_ADDR_LEN,
 		(void *)&e, sizeof(e));

 #ifdef CONFIG_SYS_EEPROM_BUS_NUM
 	i2c_set_bus_num(bus);
 #endif

 #ifdef DEBUG
 	show_eeprom();
 #endif

 	has_been_read = (ret == 0) ? 1 : 0;

 	return ret;
 }

 /**
  *  update_crc - update the CRC
  *
  *  This function should be called after each update to the EEPROM structure,
  *  to make sure the CRC is always correct.
  */
 static void update_crc(void)
 {
 	u32 crc;

 	crc = crc32(0, (void *)&e, sizeof(e) - 4);
 	e.crc = cpu_to_be32(crc);
 }

 /**
  * prog_eeprom - write the EEPROM from memory
  */
 static int prog_eeprom(void)
 {
 	int ret = 0; /* shut up gcc */
 	int i;
 	void *p;
 #ifdef CONFIG_SYS_EEPROM_BUS_NUM
 	unsigned int bus;
 #endif

 	/* Set the reserved values to 0xFF   */
 #ifdef CONFIG_SYS_I2C_EEPROM_NXID
 	e.res_0 = 0xFF;
 	memset(e.res_1, 0xFF, sizeof(e.res_1));
 #else
 	memset(e.res_0, 0xFF, sizeof(e.res_0));
 #endif
 	update_crc();

 #ifdef CONFIG_SYS_EEPROM_BUS_NUM
 	bus = i2c_get_bus_num();
 	i2c_set_bus_num(CONFIG_SYS_EEPROM_BUS_NUM);
 #endif

 	for (i = 0, p = &e; i < sizeof(e); i += 8, p += 8) {
 		ret = i2c_write(CONFIG_SYS_I2C_EEPROM_ADDR, i, CONFIG_SYS_I2C_EEPROM_ADDR_LEN,
 			p, min((sizeof(e) - i), 8));
 		if (ret)
 			break;
 		udelay(5000);	/* 5ms write cycle timing */
 	}

 #ifdef CONFIG_SYS_EEPROM_BUS_NUM
 	i2c_set_bus_num(bus);
 #endif

 	if (ret) {
 		printf("Programming failed.\n");
 		return -1;
 	}

 	printf("Programming passed.\n");
 	return 0;
 }

 /**
  * h2i - converts hex character into a number
  *
  * This function takes a hexadecimal character (e.g. '7' or 'C') and returns
  * the integer equivalent.
  */
 static inline u8 h2i(char p)
 {
 	if ((p >= '0') && (p <= '9'))
 		return p - '0';

 	if ((p >= 'A') && (p <= 'F'))
 		return (p - 'A') + 10;

 	if ((p >= 'a') && (p <= 'f'))
 		return (p - 'a') + 10;

 	return 0;
 }

 /**
  * set_date - stores the build date into the EEPROM
  *
  * This function takes a pointer to a string in the format "YYMMDDhhmmss"
  * (2-digit year, 2-digit month, etc), converts it to a 6-byte BCD string,
  * and stores it in the build date field of the EEPROM local copy.
  */
 static void set_date(const char *string)
 {
 	unsigned int i;

 	if (strlen(string) != 12) {
 		printf("Usage: mac date YYMMDDhhmmss\n");
 		return;
 	}

 	for (i = 0; i < 6; i++)
 		e.date[i] = h2i(string[2 * i]) << 4 | h2i(string[2 * i + 1]);

 	update_crc();
 }

 /**
  * set_mac_address - stores a MAC address into the EEPROM
  *
  * This function takes a pointer to MAC address string
  * (i.e."XX:XX:XX:XX:XX:XX", where "XX" is a two-digit hex number) and
  * stores it in one of the MAC address fields of the EEPROM local copy.
  */
 static void set_mac_address(unsigned int index, const char *string)
 {
 	char *p = (char *) string;
 	unsigned int i;

 	if (!string) {
 		printf("Usage: mac <n> XX:XX:XX:XX:XX:XX\n");
 		return;
 	}

 	for (i = 0; *p && (i < 6); i++) {
 		e.mac[index][i] = simple_strtoul(p, &p, 16);
 		if (*p == ':')
 			p++;
 	}

 	update_crc();
 }

 int do_mac(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	char cmd;

 	if (argc == 1) {
 		show_eeprom();
 		return 0;
 	}

 	cmd = argv[1][0];

 	if (cmd == 'r') {
 		read_eeprom();
 		return 0;
 	}

 	if (cmd == 'i') {
 #ifdef CONFIG_SYS_I2C_EEPROM_NXID
 		memcpy(e.id, "NXID", sizeof(e.id));
 		e.version = 0;
 #else
 		memcpy(e.id, "CCID", sizeof(e.id));
 #endif
 		return 0;
 	}

 	if (!is_valid) {
 		printf("Please read the EEPROM ('r') and/or set the ID ('i') first.\n");
 		return 0;
 	}

 	if (argc == 2) {
 		switch (cmd) {
 		case 's':	/* save */
 			prog_eeprom();
 			break;
 		default:
 			cmd_usage(cmdtp);
 			break;
 		}

 		return 0;
 	}

 	/* We know we have at least one parameter  */

 	switch (cmd) {
 	case 'n':	/* serial number */
 		memset(e.sn, 0, sizeof(e.sn));
 		strncpy((char *)e.sn, argv[2], sizeof(e.sn) - 1);
 		update_crc();
 		break;
 	case 'e':	/* errata */
 #ifdef CONFIG_SYS_I2C_EEPROM_NXID
 		memset(e.errata, 0, 5);
 		strncpy((char *)e.errata, argv[2], 4);
 #else
 		e.errata[0] = argv[2][0];
 		e.errata[1] = argv[2][1];
 #endif
 		update_crc();
 		break;
 	case 'd':	/* date BCD format YYMMDDhhmmss */
 		set_date(argv[2]);
 		break;
 	case 'p':	/* MAC table size */
 		e.mac_count = simple_strtoul(argv[2], NULL, 16);
 		update_crc();
 		break;
 	case '0' ... '7':	/* "mac 0" through "mac 7" */
 		set_mac_address(cmd - '0', argv[2]);
 		break;
 	case 'h':	/* help */
 	default:
 		cmd_usage(cmdtp);
 		break;
 	}

 	return 0;
 }

 /**
  * mac_read_from_eeprom - read the MAC addresses from EEPROM
  *
  * This function reads the MAC addresses from EEPROM and sets the
  * appropriate environment variables for each one read.
  *
  * The environment variables are only set if they haven't been set already.
  * This ensures that any user-saved variables are never overwritten.
  *
  * This function must be called after relocation.
  */
 int mac_read_from_eeprom(void)
 {
 	unsigned int i;
 	u32 crc;

 	puts("EEPROM: ");

 	if (read_eeprom()) {
 		printf("Read failed.\n");
 		return -1;
 	}

 	if (!is_valid) {
 		printf("Invalid ID (%02x %02x %02x %02x)\n",
 		       e.id[0], e.id[1], e.id[2], e.id[3]);
 		return -1;
 	}

 	crc = crc32(0, (void *)&e, sizeof(e) - 4);
 	if (crc != be32_to_cpu(e.crc)) {
 		printf("CRC mismatch (%08x != %08x)\n", crc, be32_to_cpu(e.crc));
 		return -1;
 	}

 	for (i = 0; i < min(e.mac_count, MAX_NUM_PORTS); i++) {
 		if (memcmp(&e.mac[i], "\0\0\0\0\0\0", 6) &&
 		    memcmp(&e.mac[i], "\xFF\xFF\xFF\xFF\xFF\xFF", 6)) {
 			char ethaddr[18];
 			char enetvar[9];

 			sprintf(ethaddr, "%02X:%02X:%02X:%02X:%02X:%02X",
 				e.mac[i][0],
 				e.mac[i][1],
 				e.mac[i][2],
 				e.mac[i][3],
 				e.mac[i][4],
 				e.mac[i][5]);
 			sprintf(enetvar, i ? "eth%daddr" : "ethaddr", i);
 			/* Only initialize environment variables that are blank
 			 * (i.e. have not yet been set)
 			 */
 			if (!getenv(enetvar))
 				setenv(enetvar, ethaddr);
 		}
 	}

 #ifdef CONFIG_SYS_I2C_EEPROM_NXID
 	printf("%c%c%c%c v%u\n", e.id[0], e.id[1], e.id[2], e.id[3],
 		be32_to_cpu(e.version));
 #else
 	printf("%c%c%c%c\n", e.id[0], e.id[1], e.id[2], e.id[3]);
 #endif

 	return 0;
 }

 #ifdef CONFIG_SYS_I2C_EEPROM_CCID

 /**
  * get_cpu_board_revision - get the CPU board revision on 85xx boards
  *
  * Read the EEPROM to determine the board revision.
  *
  * This function is called before relocation, so we need to read a private
  * copy of the EEPROM into a local variable on the stack.
  *
  * Also, we assume that CONFIG_SYS_EEPROM_BUS_NUM == CONFIG_SYS_SPD_BUS_NUM.  The global
  * variable i2c_bus_num must be compile-time initialized to CONFIG_SYS_SPD_BUS_NUM,
  * so that the SPD code will work.  This means that all pre-relocation I2C
  * operations can only occur on the CONFIG_SYS_SPD_BUS_NUM bus.  So if
  * CONFIG_SYS_EEPROM_BUS_NUM != CONFIG_SYS_SPD_BUS_NUM, then we can't read the EEPROM when
  * this function is called.  Oh well.
  */
 unsigned int get_cpu_board_revision(void)
 {
 	struct board_eeprom {
 		u32 id;           /* 0x00 - 0x03 EEPROM Tag 'CCID' */
 		u8 major;         /* 0x04        Board revision, major */
 		u8 minor;         /* 0x05        Board revision, minor */
 	} be;

 	i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, 0, CONFIG_SYS_I2C_EEPROM_ADDR_LEN,
 		(void *)&be, sizeof(be));

 	if (be.id != (('C' << 24) | ('C' << 16) | ('I' << 8) | 'D'))
 		return MPC85XX_CPU_BOARD_REV(0, 0);

 	if ((be.major == 0xff) && (be.minor == 0xff))
 		return MPC85XX_CPU_BOARD_REV(0, 0);

 	return MPC85XX_CPU_BOARD_REV(be.major, be.minor);
 }
 #endif
	/*
	* Copyright 2006, 2008-2009 Freescale Semiconductor
	* York Sun (yorksun@freescale.com)
	* Haiying Wang (haiying.wang@freescale.com)
	* Timur Tabi (timur@freescale.com)
	*
	* See file CREDITS for list of people who contributed to this
	* project.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation; either version 2 of
	* the License, or (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	* MA 02111-1307 USA
	*/

	#include <common.h>
	#include <command.h>
	#include <i2c.h>
	#include <linux/ctype.h>

	#include "../common/eeprom.h"

	#if !defined(CONFIG_SYS_I2C_EEPROM_CCID) && !defined(CONFIG_SYS_I2C_EEPROM_NXID)
	#error "Please define either CONFIG_SYS_I2C_EEPROM_CCID or CONFIG_SYS_I2C_EEPROM_NXID"
	#endif

	#define MAX_NUM_PORTS 8 /* This value must be 8 as defined in doc */

	/**
	* static eeprom: EEPROM layout for CCID or NXID formats
	*
	* See application note AN3638 for details.
	*/
	static struct __attribute__ ((__packed__)) eeprom {
	#ifdef CONFIG_SYS_I2C_EEPROM_CCID
	u8 id[4]; /* 0x00 - 0x03 EEPROM Tag 'CCID' */
	u8 major; /* 0x04 Board revision, major */
	u8 minor; /* 0x05 Board revision, minor */
	u8 sn[10]; /* 0x06 - 0x0F Serial Number*/
	u8 errata[2]; /* 0x10 - 0x11 Errata Level */
	u8 date[6]; /* 0x12 - 0x17 Build Date */
	u8 res_0[40]; /* 0x18 - 0x3f Reserved */
	u8 mac_count; /* 0x40 Number of MAC addresses */
	u8 mac_flag; /* 0x41 MAC table flags */
	u8 mac[MAX_NUM_PORTS][6]; /* 0x42 - 0x71 MAC addresses */
	u32 crc; /* 0x72 CRC32 checksum */
	#endif
	#ifdef CONFIG_SYS_I2C_EEPROM_NXID
	u8 id[4]; /* 0x00 - 0x03 EEPROM Tag 'NXID' */
	u8 sn[12]; /* 0x04 - 0x0F Serial Number */
	u8 errata[5]; /* 0x10 - 0x14 Errata Level */
	u8 date[6]; /* 0x15 - 0x1a Build Date */
	u8 res_0; /* 0x1b Reserved */
	u32 version; /* 0x1c - 0x1f NXID Version */
	u8 tempcal[8]; /* 0x20 - 0x27 Temperature Calibration Factors */
	u8 tempcalsys[2]; /* 0x28 - 0x29 System Temperature Calibration Factors */
	u8 tempcalflags; /* 0x2a Temperature Calibration Flags */
	u8 res_1[21]; /* 0x2b - 0x3f Reserved */
	u8 mac_count; /* 0x40 Number of MAC addresses */
	u8 mac_flag; /* 0x41 MAC table flags */
	u8 mac[MAX_NUM_PORTS][6]; /* 0x42 - 0x71 MAC addresses */
	u32 crc; /* 0x72 CRC32 checksum */
	#endif
	} e;

	/* Set to 1 if we've read EEPROM into memory */
	static int has_been_read = 0;

	#ifdef CONFIG_SYS_I2C_EEPROM_NXID
	/* Is this a valid NXID EEPROM? */
	#define is_valid ((e.id[0] == 'N') \|\| (e.id[1] == 'X') \|\| \
	(e.id[2] == 'I') \|\| (e.id[3] == 'D'))
	#endif

	#ifdef CONFIG_SYS_I2C_EEPROM_CCID
	/* Is this a valid CCID EEPROM? */
	#define is_valid ((e.id[0] == 'C') \|\| (e.id[1] == 'C') \|\| \
	(e.id[2] == 'I') \|\| (e.id[3] == 'D'))
	#endif

	/**
	* show_eeprom - display the contents of the EEPROM
	*/
	static void show_eeprom(void)
	{
	int i;
	unsigned int crc;

	/* EEPROM tag ID, either CCID or NXID */
	#ifdef CONFIG_SYS_I2C_EEPROM_NXID
	printf("ID: %c%c%c%c v%u\n", e.id[0], e.id[1], e.id[2], e.id[3],
	be32_to_cpu(e.version));
	#else
	printf("ID: %c%c%c%c\n", e.id[0], e.id[1], e.id[2], e.id[3]);
	#endif

	/* Serial number */
	printf("SN: %s\n", e.sn);

	/* Errata level. */
	#ifdef CONFIG_SYS_I2C_EEPROM_NXID
	printf("Errata: %s\n", e.errata);
	#else
	printf("Errata: %c%c\n",
	e.errata[0] ? e.errata[0] : '.',
	e.errata[1] ? e.errata[1] : '.');
	#endif

	/* Build date, BCD date values, as YYMMDDhhmmss */
	printf("Build date: 20%02x/%02x/%02x %02x:%02x:%02x %s\n",
	e.date[0], e.date[1], e.date[2],
	e.date[3] & 0x7F, e.date[4], e.date[5],
	e.date[3] & 0x80 ? "PM" : "");

	/* Show MAC addresses */
	for (i = 0; i < min(e.mac_count, MAX_NUM_PORTS); i++) {

	u8 *p = e.mac[i];

	printf("Eth%u: %02x:%02x:%02x:%02x:%02x:%02x\n", i,
	p[0], p[1], p[2], p[3], p[4], p[5]);
	}

	crc = crc32(0, (void *)&e, sizeof(e) - 4);

	if (crc == be32_to_cpu(e.crc))
	printf("CRC: %08x\n", be32_to_cpu(e.crc));
	else
	printf("CRC: %08x (should be %08x)\n",
	be32_to_cpu(e.crc), crc);

	#ifdef DEBUG
	printf("EEPROM dump: (0x%x bytes)\n", sizeof(e));
	for (i = 0; i < sizeof(e); i++) {
	if ((i % 16) == 0)
	printf("%02X: ", i);
	printf("%02X ", ((u8 *)&e)[i]);
	if (((i % 16) == 15) \|\| (i == sizeof(e) - 1))
	printf("\n");
	}
	#endif
	}

	/**
	* read_eeprom - read the EEPROM into memory
	*/
	static int read_eeprom(void)
	{
	int ret;
	#ifdef CONFIG_SYS_EEPROM_BUS_NUM
	unsigned int bus;
	#endif

	if (has_been_read)
	return 0;

	#ifdef CONFIG_SYS_EEPROM_BUS_NUM
	bus = i2c_get_bus_num();
	i2c_set_bus_num(CONFIG_SYS_EEPROM_BUS_NUM);
	#endif

	ret = i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, 0, CONFIG_SYS_I2C_EEPROM_ADDR_LEN,
	(void *)&e, sizeof(e));

	#ifdef CONFIG_SYS_EEPROM_BUS_NUM
	i2c_set_bus_num(bus);
	#endif

	#ifdef DEBUG
	show_eeprom();
	#endif

	has_been_read = (ret == 0) ? 1 : 0;

	return ret;
	}

	/**
	* update_crc - update the CRC
	*
	* This function should be called after each update to the EEPROM structure,
	* to make sure the CRC is always correct.
	*/
	static void update_crc(void)
	{
	u32 crc;

	crc = crc32(0, (void *)&e, sizeof(e) - 4);
	e.crc = cpu_to_be32(crc);
	}

	/**
	* prog_eeprom - write the EEPROM from memory
	*/
	static int prog_eeprom(void)
	{
	int ret = 0; /* shut up gcc */
	int i;
	void *p;
	#ifdef CONFIG_SYS_EEPROM_BUS_NUM
	unsigned int bus;
	#endif

	/* Set the reserved values to 0xFF */
	#ifdef CONFIG_SYS_I2C_EEPROM_NXID
	e.res_0 = 0xFF;
	memset(e.res_1, 0xFF, sizeof(e.res_1));
	#else
	memset(e.res_0, 0xFF, sizeof(e.res_0));
	#endif
	update_crc();

	#ifdef CONFIG_SYS_EEPROM_BUS_NUM
	bus = i2c_get_bus_num();
	i2c_set_bus_num(CONFIG_SYS_EEPROM_BUS_NUM);
	#endif

	for (i = 0, p = &e; i < sizeof(e); i += 8, p += 8) {
	ret = i2c_write(CONFIG_SYS_I2C_EEPROM_ADDR, i, CONFIG_SYS_I2C_EEPROM_ADDR_LEN,
	p, min((sizeof(e) - i), 8));
	if (ret)
	break;
	udelay(5000); /* 5ms write cycle timing */
	}

	#ifdef CONFIG_SYS_EEPROM_BUS_NUM
	i2c_set_bus_num(bus);
	#endif

	if (ret) {
	printf("Programming failed.\n");
	return -1;
	}

	printf("Programming passed.\n");
	return 0;
	}

	/**
	* h2i - converts hex character into a number
	*
	* This function takes a hexadecimal character (e.g. '7' or 'C') and returns
	* the integer equivalent.
	*/
	static inline u8 h2i(char p)
	{
	if ((p >= '0') && (p <= '9'))
	return p - '0';

	if ((p >= 'A') && (p <= 'F'))
	return (p - 'A') + 10;

	if ((p >= 'a') && (p <= 'f'))
	return (p - 'a') + 10;

	return 0;
	}

	/**
	* set_date - stores the build date into the EEPROM
	*
	* This function takes a pointer to a string in the format "YYMMDDhhmmss"
	* (2-digit year, 2-digit month, etc), converts it to a 6-byte BCD string,
	* and stores it in the build date field of the EEPROM local copy.
	*/
	static void set_date(const char *string)
	{
	unsigned int i;

	if (strlen(string) != 12) {
	printf("Usage: mac date YYMMDDhhmmss\n");
	return;
	}

	for (i = 0; i < 6; i++)
	e.date[i] = h2i(string[2 * i]) << 4 \| h2i(string[2 * i + 1]);

	update_crc();
	}

	/**
	* set_mac_address - stores a MAC address into the EEPROM
	*
	* This function takes a pointer to MAC address string
	* (i.e."XX:XX:XX:XX:XX:XX", where "XX" is a two-digit hex number) and
	* stores it in one of the MAC address fields of the EEPROM local copy.
	*/
	static void set_mac_address(unsigned int index, const char *string)
	{
	char p = (char ) string;
	unsigned int i;

	if (!string) {
	printf("Usage: mac <n> XX:XX:XX:XX:XX:XX\n");
	return;
	}

	for (i = 0; *p && (i < 6); i++) {
	e.mac[index][i] = simple_strtoul(p, &p, 16);
	if (*p == ':')
	p++;
	}

	update_crc();
	}

	int do_mac(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	char cmd;

	if (argc == 1) {
	show_eeprom();
	return 0;
	}

	cmd = argv[1][0];

	if (cmd == 'r') {
	read_eeprom();
	return 0;
	}

	if (cmd == 'i') {
	#ifdef CONFIG_SYS_I2C_EEPROM_NXID
	memcpy(e.id, "NXID", sizeof(e.id));
	e.version = 0;
	#else
	memcpy(e.id, "CCID", sizeof(e.id));
	#endif
	return 0;
	}

	if (!is_valid) {
	printf("Please read the EEPROM ('r') and/or set the ID ('i') first.\n");
	return 0;
	}

	if (argc == 2) {
	switch (cmd) {
	case 's': /* save */
	prog_eeprom();
	break;
	default:
	cmd_usage(cmdtp);
	break;
	}

	return 0;
	}

	/* We know we have at least one parameter */

	switch (cmd) {
	case 'n': /* serial number */
	memset(e.sn, 0, sizeof(e.sn));
	strncpy((char *)e.sn, argv[2], sizeof(e.sn) - 1);
	update_crc();
	break;
	case 'e': /* errata */
	#ifdef CONFIG_SYS_I2C_EEPROM_NXID
	memset(e.errata, 0, 5);
	strncpy((char *)e.errata, argv[2], 4);
	#else
	e.errata[0] = argv[2][0];
	e.errata[1] = argv[2][1];
	#endif
	update_crc();
	break;
	case 'd': /* date BCD format YYMMDDhhmmss */
	set_date(argv[2]);
	break;
	case 'p': /* MAC table size */
	e.mac_count = simple_strtoul(argv[2], NULL, 16);
	update_crc();
	break;
	case '0' ... '7': /* "mac 0" through "mac 7" */
	set_mac_address(cmd - '0', argv[2]);
	break;
	case 'h': /* help */
	default:
	cmd_usage(cmdtp);
	break;
	}

	return 0;
	}

	/**
	* mac_read_from_eeprom - read the MAC addresses from EEPROM
	*
	* This function reads the MAC addresses from EEPROM and sets the
	* appropriate environment variables for each one read.
	*
	* The environment variables are only set if they haven't been set already.
	* This ensures that any user-saved variables are never overwritten.
	*
	* This function must be called after relocation.
	*/
	int mac_read_from_eeprom(void)
	{
	unsigned int i;
	u32 crc;

	puts("EEPROM: ");

	if (read_eeprom()) {
	printf("Read failed.\n");
	return -1;
	}

	if (!is_valid) {
	printf("Invalid ID (%02x %02x %02x %02x)\n",
	e.id[0], e.id[1], e.id[2], e.id[3]);
	return -1;
	}

	crc = crc32(0, (void *)&e, sizeof(e) - 4);
	if (crc != be32_to_cpu(e.crc)) {
	printf("CRC mismatch (%08x != %08x)\n", crc, be32_to_cpu(e.crc));
	return -1;
	}

	for (i = 0; i < min(e.mac_count, MAX_NUM_PORTS); i++) {
	if (memcmp(&e.mac[i], "\0\0\0\0\0\0", 6) &&
	memcmp(&e.mac[i], "\xFF\xFF\xFF\xFF\xFF\xFF", 6)) {
	char ethaddr[18];
	char enetvar[9];

	sprintf(ethaddr, "%02X:%02X:%02X:%02X:%02X:%02X",
	e.mac[i][0],
	e.mac[i][1],
	e.mac[i][2],
	e.mac[i][3],
	e.mac[i][4],
	e.mac[i][5]);
	sprintf(enetvar, i ? "eth%daddr" : "ethaddr", i);
	/* Only initialize environment variables that are blank
	* (i.e. have not yet been set)
	*/
	if (!getenv(enetvar))
	setenv(enetvar, ethaddr);
	}
	}

	#ifdef CONFIG_SYS_I2C_EEPROM_NXID
	printf("%c%c%c%c v%u\n", e.id[0], e.id[1], e.id[2], e.id[3],
	be32_to_cpu(e.version));
	#else
	printf("%c%c%c%c\n", e.id[0], e.id[1], e.id[2], e.id[3]);
	#endif

	return 0;
	}

	#ifdef CONFIG_SYS_I2C_EEPROM_CCID

	/**
	* get_cpu_board_revision - get the CPU board revision on 85xx boards
	*
	* Read the EEPROM to determine the board revision.
	*
	* This function is called before relocation, so we need to read a private
	* copy of the EEPROM into a local variable on the stack.
	*
	* Also, we assume that CONFIG_SYS_EEPROM_BUS_NUM == CONFIG_SYS_SPD_BUS_NUM. The global
	* variable i2c_bus_num must be compile-time initialized to CONFIG_SYS_SPD_BUS_NUM,
	* so that the SPD code will work. This means that all pre-relocation I2C
	* operations can only occur on the CONFIG_SYS_SPD_BUS_NUM bus. So if
	* CONFIG_SYS_EEPROM_BUS_NUM != CONFIG_SYS_SPD_BUS_NUM, then we can't read the EEPROM when
	* this function is called. Oh well.
	*/
	unsigned int get_cpu_board_revision(void)
	{
	struct board_eeprom {
	u32 id; /* 0x00 - 0x03 EEPROM Tag 'CCID' */
	u8 major; /* 0x04 Board revision, major */
	u8 minor; /* 0x05 Board revision, minor */
	} be;

	i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, 0, CONFIG_SYS_I2C_EEPROM_ADDR_LEN,
	(void *)&be, sizeof(be));

	if (be.id != (('C' << 24) \| ('C' << 16) \| ('I' << 8) \| 'D'))
	return MPC85XX_CPU_BOARD_REV(0, 0);

	if ((be.major == 0xff) && (be.minor == 0xff))
	return MPC85XX_CPU_BOARD_REV(0, 0);

	return MPC85XX_CPU_BOARD_REV(be.major, be.minor);
	}
	#endif