cmd: add tlv_eeprom command

Add support for read/write of ONIE "Tlvinfo" EEPROM data format. TLV
stands for Type-Length-Value. The data format is described here:

  https://opencomputeproject.github.io/onie/design-spec/hw_requirements.html#board-eeprom-information-format

Based on U-Boot patch from the Open Compute project:

  https://github.com/opencomputeproject/onie/blob/ec87e872d46b9805565d2c6124b2f701ef1c07b1/patches/u-boot/common/feature-sys-eeprom-tlv-common.patch

Keep only I2C EEPROM support. Use the generic eeprom driver. Fix
checkpatch issues.

Add support for multiple EEPROM TLV stores on the same system. This is
useful in case of SOM and carrier that both provide ID and hardware
configuration information.

Add option to enable for SPL. This allows selection of RAM configuration
based on EEPROM stored board identification.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>

1 files changed, 1105 insertions, 0 deletions

diff --git a/cmd/tlv_eeprom.c b/cmd/tlv_eeprom.c
new file mode 100644
index 0000000000..211ab2680f
--- /dev/null
+++ b/cmd/tlv_eeprom.c
@@ -0,0 +1,1105 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * Copyright (C) 2013 Curt Brune <curt@cumulusnetworks.com>
+ * Copyright (C) 2014 Srideep <srideep_devireddy@dell.com>
+ * Copyright (C) 2013 Miles Tseng <miles_tseng@accton.com>
+ * Copyright (C) 2014,2016 david_yang <david_yang@accton.com>
+ */
+
+#include <common.h>
+#include <command.h>
+#include <dm.h>
+#include <i2c.h>
+#include <i2c_eeprom.h>
+#include <env.h>
+#include <linux/ctype.h>
+#include <u-boot/crc.h>
+
+#include "tlv_eeprom.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define MAX_TLV_DEVICES	2
+
+/* File scope function prototypes */
+static bool is_checksum_valid(u8 *eeprom);
+static int read_eeprom(u8 *eeprom);
+static void show_eeprom(u8 *eeprom);
+static void decode_tlv(struct tlvinfo_tlv *tlv);
+static void update_crc(u8 *eeprom);
+static int prog_eeprom(u8 *eeprom);
+static bool tlvinfo_find_tlv(u8 *eeprom, u8 tcode, int *eeprom_index);
+static bool tlvinfo_delete_tlv(u8 *eeprom, u8 code);
+static bool tlvinfo_add_tlv(u8 *eeprom, int tcode, char *strval);
+static int set_mac(char *buf, const char *string);
+static int set_date(char *buf, const char *string);
+static int set_bytes(char *buf, const char *string, int *converted_accum);
+static void show_tlv_devices(void);
+
+/* Set to 1 if we've read EEPROM into memory */
+static int has_been_read;
+/* The EERPOM contents after being read into memory */
+static u8 eeprom[TLV_INFO_MAX_LEN];
+
+static struct udevice *tlv_devices[MAX_TLV_DEVICES];
+static unsigned int current_dev;
+
+#define to_header(p) ((struct tlvinfo_header *)p)
+#define to_entry(p) ((struct tlvinfo_tlv *)p)
+
+#define HDR_SIZE sizeof(struct tlvinfo_header)
+#define ENT_SIZE sizeof(struct tlvinfo_tlv)
+
+static inline bool is_digit(char c)
+{
+	return (c >= '0' && c <= '9');
+}
+
+/**
+ *  is_valid_tlv
+ *
+ *  Perform basic sanity checks on a TLV field. The TLV is pointed to
+ *  by the parameter provided.
+ *      1. The type code is not reserved (0x00 or 0xFF)
+ */
+static inline bool is_valid_tlv(struct tlvinfo_tlv *tlv)
+{
+	return((tlv->type != 0x00) && (tlv->type != 0xFF));
+}
+
+/**
+ *  is_hex
+ *
+ *  Tests if character is an ASCII hex digit
+ */
+static inline u8 is_hex(char p)
+{
+	return (((p >= '0') && (p <= '9')) ||
+		((p >= 'A') && (p <= 'F')) ||
+		((p >= 'a') && (p <= 'f')));
+}
+
+/**
+ *  is_checksum_valid
+ *
+ *  Validate the checksum in the provided TlvInfo EEPROM data. First,
+ *  verify that the TlvInfo header is valid, then make sure the last
+ *  TLV is a CRC-32 TLV. Then calculate the CRC over the EEPROM data
+ *  and compare it to the value stored in the EEPROM CRC-32 TLV.
+ */
+static bool is_checksum_valid(u8 *eeprom)
+{
+	struct tlvinfo_header *eeprom_hdr = to_header(eeprom);
+	struct tlvinfo_tlv    *eeprom_crc;
+	unsigned int       calc_crc;
+	unsigned int       stored_crc;
+
+	// Is the eeprom header valid?
+	if (!is_valid_tlvinfo_header(eeprom_hdr))
+		return false;
+
+	// Is the last TLV a CRC?
+	eeprom_crc = to_entry(&eeprom[HDR_SIZE +
+		be16_to_cpu(eeprom_hdr->totallen) - (ENT_SIZE + 4)]);
+	if (eeprom_crc->type != TLV_CODE_CRC_32 || eeprom_crc->length != 4)
+		return false;
+
+	// Calculate the checksum
+	calc_crc = crc32(0, (void *)eeprom,
+			 HDR_SIZE + be16_to_cpu(eeprom_hdr->totallen) - 4);
+	stored_crc = (eeprom_crc->value[0] << 24) |
+		(eeprom_crc->value[1] << 16) |
+		(eeprom_crc->value[2] <<  8) |
+		eeprom_crc->value[3];
+	return calc_crc == stored_crc;
+}
+
+/**
+ *  read_eeprom
+ *
+ *  Read the EEPROM into memory, if it hasn't already been read.
+ */
+static int read_eeprom(u8 *eeprom)
+{
+	int ret;
+	struct tlvinfo_header *eeprom_hdr = to_header(eeprom);
+	struct tlvinfo_tlv *eeprom_tlv = to_entry(&eeprom[HDR_SIZE]);
+
+	if (has_been_read)
+		return 0;
+
+	/* Read the header */
+	ret = read_tlv_eeprom((void *)eeprom_hdr, 0, HDR_SIZE, current_dev);
+	/* If the header was successfully read, read the TLVs */
+	if (ret == 0 && is_valid_tlvinfo_header(eeprom_hdr))
+		ret = read_tlv_eeprom((void *)eeprom_tlv, HDR_SIZE,
+				      be16_to_cpu(eeprom_hdr->totallen),
+				      current_dev);
+
+	// If the contents are invalid, start over with default contents
+	if (!is_valid_tlvinfo_header(eeprom_hdr) ||
+	    !is_checksum_valid(eeprom)) {
+		strcpy(eeprom_hdr->signature, TLV_INFO_ID_STRING);
+		eeprom_hdr->version = TLV_INFO_VERSION;
+		eeprom_hdr->totallen = cpu_to_be16(0);
+		update_crc(eeprom);
+	}
+
+	has_been_read = 1;
+
+#ifdef DEBUG
+	show_eeprom(eeprom);
+#endif
+
+	return ret;
+}
+
+/**
+ *  show_eeprom
+ *
+ *  Display the contents of the EEPROM
+ */
+static void show_eeprom(u8 *eeprom)
+{
+	int tlv_end;
+	int curr_tlv;
+	struct tlvinfo_header *eeprom_hdr = to_header(eeprom);
+	struct tlvinfo_tlv    *eeprom_tlv;
+
+	if (!is_valid_tlvinfo_header(eeprom_hdr)) {
+		printf("EEPROM does not contain data in a valid TlvInfo format.\n");
+		return;
+	}
+
+	printf("TLV: %u\n", current_dev);
+	printf("TlvInfo Header:\n");
+	printf("   Id String:    %s\n", eeprom_hdr->signature);
+	printf("   Version:      %d\n", eeprom_hdr->version);
+	printf("   Total Length: %d\n", be16_to_cpu(eeprom_hdr->totallen));
+
+	printf("TLV Name             Code Len Value\n");
+	printf("-------------------- ---- --- -----\n");
+	curr_tlv = HDR_SIZE;
+	tlv_end  = HDR_SIZE + be16_to_cpu(eeprom_hdr->totallen);
+	while (curr_tlv < tlv_end) {
+		eeprom_tlv = to_entry(&eeprom[curr_tlv]);
+		if (!is_valid_tlv(eeprom_tlv)) {
+			printf("Invalid TLV field starting at EEPROM offset %d\n",
+			       curr_tlv);
+			return;
+		}
+		decode_tlv(eeprom_tlv);
+		curr_tlv += ENT_SIZE + eeprom_tlv->length;
+	}
+
+	printf("Checksum is %s.\n",
+	       is_checksum_valid(eeprom) ? "valid" : "invalid");
+
+#ifdef DEBUG
+	printf("EEPROM dump: (0x%x bytes)", TLV_INFO_MAX_LEN);
+	for (i = 0; i < TLV_INFO_MAX_LEN; i++) {
+		if ((i % 16) == 0)
+			printf("\n%02X: ", i);
+		printf("%02X ", eeprom[i]);
+	}
+	printf("\n");
+#endif
+}
+
+/**
+ *  Struct for displaying the TLV codes and names.
+ */
+struct tlv_code_desc {
+	u8    m_code;
+	char *m_name;
+};
+
+/**
+ *  List of TLV codes and names.
+ */
+static struct tlv_code_desc tlv_code_list[] = {
+	{ TLV_CODE_PRODUCT_NAME,   "Product Name"},
+	{ TLV_CODE_PART_NUMBER,    "Part Number"},
+	{ TLV_CODE_SERIAL_NUMBER,  "Serial Number"},
+	{ TLV_CODE_MAC_BASE,       "Base MAC Address"},
+	{ TLV_CODE_MANUF_DATE,     "Manufacture Date"},
+	{ TLV_CODE_DEVICE_VERSION, "Device Version"},
+	{ TLV_CODE_LABEL_REVISION, "Label Revision"},
+	{ TLV_CODE_PLATFORM_NAME,  "Platform Name"},
+	{ TLV_CODE_ONIE_VERSION,   "ONIE Version"},
+	{ TLV_CODE_MAC_SIZE,       "MAC Addresses"},
+	{ TLV_CODE_MANUF_NAME,     "Manufacturer"},
+	{ TLV_CODE_MANUF_COUNTRY,  "Country Code"},
+	{ TLV_CODE_VENDOR_NAME,    "Vendor Name"},
+	{ TLV_CODE_DIAG_VERSION,   "Diag Version"},
+	{ TLV_CODE_SERVICE_TAG,    "Service Tag"},
+	{ TLV_CODE_VENDOR_EXT,     "Vendor Extension"},
+	{ TLV_CODE_CRC_32,         "CRC-32"},
+};
+
+/**
+ *  Look up a TLV name by its type.
+ */
+static inline const char *tlv_type2name(u8 type)
+{
+	char *name = "Unknown";
+	int   i;
+
+	for (i = 0; i < ARRAY_SIZE(tlv_code_list); i++) {
+		if (tlv_code_list[i].m_code == type) {
+			name = tlv_code_list[i].m_name;
+			break;
+		}
+	}
+
+	return name;
+}
+
+/*
+ *  decode_tlv
+ *
+ *  Print a string representing the contents of the TLV field. The format of
+ *  the string is:
+ *      1. The name of the field left justified in 20 characters
+ *      2. The type code in hex right justified in 5 characters
+ *      3. The length in decimal right justified in 4 characters
+ *      4. The value, left justified in however many characters it takes
+ *  The validity of EEPROM contents and the TLV field have been verified
+ *  prior to calling this function.
+ */
+#define DECODE_NAME_MAX     20
+
+/*
+ * The max decode value is currently for the 'raw' type or the 'vendor
+ * extension' type, both of which have the same decode format.  The
+ * max decode string size is computed as follows:
+ *
+ *   strlen(" 0xFF") * TLV_VALUE_MAX_LEN + 1
+ *
+ */
+#define DECODE_VALUE_MAX    ((5 * TLV_VALUE_MAX_LEN) + 1)
+
+static void decode_tlv(struct tlvinfo_tlv *tlv)
+{
+	char name[DECODE_NAME_MAX];
+	char value[DECODE_VALUE_MAX];
+	int i;
+
+	strncpy(name, tlv_type2name(tlv->type), DECODE_NAME_MAX);
+
+	switch (tlv->type) {
+	case TLV_CODE_PRODUCT_NAME:
+	case TLV_CODE_PART_NUMBER:
+	case TLV_CODE_SERIAL_NUMBER:
+	case TLV_CODE_MANUF_DATE:
+	case TLV_CODE_LABEL_REVISION:
+	case TLV_CODE_PLATFORM_NAME:
+	case TLV_CODE_ONIE_VERSION:
+	case TLV_CODE_MANUF_NAME:
+	case TLV_CODE_MANUF_COUNTRY:
+	case TLV_CODE_VENDOR_NAME:
+	case TLV_CODE_DIAG_VERSION:
+	case TLV_CODE_SERVICE_TAG:
+		memcpy(value, tlv->value, tlv->length);
+		value[tlv->length] = 0;
+		break;
+	case TLV_CODE_MAC_BASE:
+		sprintf(value, "%02X:%02X:%02X:%02X:%02X:%02X",
+			tlv->value[0], tlv->value[1], tlv->value[2],
+			tlv->value[3], tlv->value[4], tlv->value[5]);
+		break;
+	case TLV_CODE_DEVICE_VERSION:
+		sprintf(value, "%u", tlv->value[0]);
+		break;
+	case TLV_CODE_MAC_SIZE:
+		sprintf(value, "%u", (tlv->value[0] << 8) | tlv->value[1]);
+		break;
+	case TLV_CODE_VENDOR_EXT:
+		value[0] = 0;
+		for (i = 0; (i < (DECODE_VALUE_MAX / 5)) && (i < tlv->length);
+				i++) {
+			sprintf(value, "%s 0x%02X", value, tlv->value[i]);
+		}
+		break;
+	case TLV_CODE_CRC_32:
+		sprintf(value, "0x%02X%02X%02X%02X",
+			tlv->value[0], tlv->value[1],
+			tlv->value[2], tlv->value[3]);
+		break;
+	default:
+		value[0] = 0;
+		for (i = 0; (i < (DECODE_VALUE_MAX / 5)) && (i < tlv->length);
+				i++) {
+			sprintf(value, "%s 0x%02X", value, tlv->value[i]);
+		}
+		break;
+	}
+
+	name[DECODE_NAME_MAX - 1] = 0;
+	printf("%-20s 0x%02X %3d %s\n", name, tlv->type, tlv->length, value);
+}
+
+/**
+ *  update_crc
+ *
+ *  This function updates the CRC-32 TLV. If there is no CRC-32 TLV, then
+ *  one is added. This function should be called after each update to the
+ *  EEPROM structure, to make sure the CRC is always correct.
+ */
+static void update_crc(u8 *eeprom)
+{
+	struct tlvinfo_header *eeprom_hdr = to_header(eeprom);
+	struct tlvinfo_tlv    *eeprom_crc;
+	unsigned int      calc_crc;
+	int               eeprom_index;
+
+	// Discover the CRC TLV
+	if (!tlvinfo_find_tlv(eeprom, TLV_CODE_CRC_32, &eeprom_index)) {
+		unsigned int totallen = be16_to_cpu(eeprom_hdr->totallen);
+
+		if ((totallen + ENT_SIZE + 4) > TLV_TOTAL_LEN_MAX)
+			return;
+		eeprom_index = HDR_SIZE + totallen;
+		eeprom_hdr->totallen = cpu_to_be16(totallen + ENT_SIZE + 4);
+	}
+	eeprom_crc = to_entry(&eeprom[eeprom_index]);
+	eeprom_crc->type = TLV_CODE_CRC_32;
+	eeprom_crc->length = 4;
+
+	// Calculate the checksum
+	calc_crc = crc32(0, (void *)eeprom,
+			 HDR_SIZE + be16_to_cpu(eeprom_hdr->totallen) - 4);
+	eeprom_crc->value[0] = (calc_crc >> 24) & 0xFF;
+	eeprom_crc->value[1] = (calc_crc >> 16) & 0xFF;
+	eeprom_crc->value[2] = (calc_crc >>  8) & 0xFF;
+	eeprom_crc->value[3] = (calc_crc >>  0) & 0xFF;
+}
+
+/**
+ *  prog_eeprom
+ *
+ *  Write the EEPROM data from CPU memory to the hardware.
+ */
+static int prog_eeprom(u8 *eeprom)
+{
+	int ret = 0;
+	struct tlvinfo_header *eeprom_hdr = to_header(eeprom);
+	int eeprom_len;
+
+	update_crc(eeprom);
+
+	eeprom_len = HDR_SIZE + be16_to_cpu(eeprom_hdr->totallen);
+	ret = write_tlv_eeprom(eeprom, eeprom_len);
+	if (ret) {
+		printf("Programming failed.\n");
+		return -1;
+	}
+
+	printf("Programming passed.\n");
+	return 0;
+}
+
+/**
+ *  show_tlv_code_list - Display the list of TLV codes and names
+ */
+void show_tlv_code_list(void)
+{
+	int i;
+
+	printf("TLV Code    TLV Name\n");
+	printf("========    =================\n");
+	for (i = 0; i < ARRAY_SIZE(tlv_code_list); i++) {
+		printf("0x%02X        %s\n",
+		       tlv_code_list[i].m_code,
+		       tlv_code_list[i].m_name);
+	}
+}
+
+/**
+ *  do_tlv_eeprom
+ *
+ *  This function implements the tlv_eeprom command.
+ */
+int do_tlv_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	char cmd;
+	struct tlvinfo_header *eeprom_hdr = to_header(eeprom);
+
+	// If no arguments, read the EERPOM and display its contents
+	if (argc == 1) {
+		read_eeprom(eeprom);
+		show_eeprom(eeprom);
+		return 0;
+	}
+
+	// We only look at the first character to the command, so "read" and
+	// "reset" will both be treated as "read".
+	cmd = argv[1][0];
+
+	// Read the EEPROM contents
+	if (cmd == 'r') {
+		has_been_read = 0;
+		if (!read_eeprom(eeprom))
+			printf("EEPROM data loaded from device to memory.\n");
+		return 0;
+	}
+
+	// Subsequent commands require that the EEPROM has already been read.
+	if (!has_been_read) {
+		printf("Please read the EEPROM data first, using the 'tlv_eeprom read' command.\n");
+		return 0;
+	}
+
+	// Handle the commands that don't take parameters
+	if (argc == 2) {
+		switch (cmd) {
+		case 'w':   /* write */
+			prog_eeprom(eeprom);
+			break;
+		case 'e':   /* erase */
+			strcpy(eeprom_hdr->signature, TLV_INFO_ID_STRING);
+			eeprom_hdr->version = TLV_INFO_VERSION;
+			eeprom_hdr->totallen = cpu_to_be16(0);
+			update_crc(eeprom);
+			printf("EEPROM data in memory reset.\n");
+			break;
+		case 'l':   /* list */
+			show_tlv_code_list();
+			break;
+		case 'd':   /* dev */
+			show_tlv_devices();
+			break;
+		default:
+			cmd_usage(cmdtp);
+			break;
+		}
+		return 0;
+	}
+
+	// The set command takes one or two args.
+	if (argc > 4) {
+		cmd_usage(cmdtp);
+		return 0;
+	}
+
+	// Set command. If the TLV exists in the EEPROM, delete it. Then if
+	// data was supplied for this TLV add the TLV with the new contents at
+	// the end.
+	if (cmd == 's') {
+		int tcode;
+
+		tcode = simple_strtoul(argv[2], NULL, 0);
+		tlvinfo_delete_tlv(eeprom, tcode);
+		if (argc == 4)
+			tlvinfo_add_tlv(eeprom, tcode, argv[3]);
+	} else if (cmd == 'd') { /* 'dev' command */
+		unsigned int devnum;
+
+		devnum = simple_strtoul(argv[2], NULL, 0);
+		if (devnum > MAX_TLV_DEVICES || !tlv_devices[devnum]) {
+			printf("Invalid device number\n");
+			return 0;
+		}
+		current_dev = devnum;
+		has_been_read = 0;
+	} else {
+		cmd_usage(cmdtp);
+	}
+
+	return 0;
+}
+
+/**
+ *  This macro defines the tlv_eeprom command line command.
+ */
+U_BOOT_CMD(tlv_eeprom, 4, 1,  do_tlv_eeprom,
+	   "Display and program the system EEPROM data block.",
+	   "[read|write|set <type_code> <string_value>|erase|list]\n"
+	   "tlv_eeprom\n"
+	   "    - With no arguments display the current contents.\n"
+	   "tlv_eeprom dev [dev]\n"
+	   "    - List devices or set current EEPROM device.\n"
+	   "tlv_eeprom read\n"
+	   "    - Load EEPROM data from device to memory.\n"
+	   "tlv_eeprom write\n"
+	   "    - Write the EEPROM data to persistent storage.\n"
+	   "tlv_eeprom set <type_code> <string_value>\n"
+	   "    - Set a field to a value.\n"
+	   "    - If no string_value, field is deleted.\n"
+	   "    - Use 'tlv_eeprom write' to make changes permanent.\n"
+	   "tlv_eeprom erase\n"
+	   "    - Reset the in memory EEPROM data.\n"
+	   "    - Use 'tlv_eeprom read' to refresh the in memory EEPROM data.\n"
+	   "    - Use 'tlv_eeprom write' to make changes permanent.\n"
+	   "tlv_eeprom list\n"
+	   "    - List the understood TLV codes and names.\n"
+	);
+
+/**
+ *  tlvinfo_find_tlv
+ *
+ *  This function finds the TLV with the supplied code in the EERPOM.
+ *  An offset from the beginning of the EEPROM is returned in the
+ *  eeprom_index parameter if the TLV is found.
+ */
+static bool tlvinfo_find_tlv(u8 *eeprom, u8 tcode, int *eeprom_index)
+{
+	struct tlvinfo_header *eeprom_hdr = to_header(eeprom);
+	struct tlvinfo_tlv    *eeprom_tlv;
+	int eeprom_end;
+
+	// Search through the TLVs, looking for the first one which matches the
+	// supplied type code.
+	*eeprom_index = HDR_SIZE;
+	eeprom_end = HDR_SIZE + be16_to_cpu(eeprom_hdr->totallen);
+	while (*eeprom_index < eeprom_end) {
+		eeprom_tlv = to_entry(&eeprom[*eeprom_index]);
+		if (!is_valid_tlv(eeprom_tlv))
+			return false;
+		if (eeprom_tlv->type == tcode)
+			return true;
+		*eeprom_index += ENT_SIZE + eeprom_tlv->length;
+	}
+	return(false);
+}
+
+/**
+ *  tlvinfo_delete_tlv
+ *
+ *  This function deletes the TLV with the specified type code from the
+ *  EEPROM.
+ */
+static bool tlvinfo_delete_tlv(u8 *eeprom, u8 code)
+{
+	int eeprom_index;
+	int tlength;
+	struct tlvinfo_header *eeprom_hdr = to_header(eeprom);
+	struct tlvinfo_tlv *eeprom_tlv;
+
+	// Find the TLV and then move all following TLVs "forward"
+	if (tlvinfo_find_tlv(eeprom, code, &eeprom_index)) {
+		eeprom_tlv = to_entry(&eeprom[eeprom_index]);
+		tlength = ENT_SIZE + eeprom_tlv->length;
+		memcpy(&eeprom[eeprom_index], &eeprom[eeprom_index + tlength],
+		       HDR_SIZE +
+		       be16_to_cpu(eeprom_hdr->totallen) - eeprom_index -
+		       tlength);
+		eeprom_hdr->totallen =
+			cpu_to_be16(be16_to_cpu(eeprom_hdr->totallen) -
+				    tlength);
+		update_crc(eeprom);
+		return true;
+	}
+	return false;
+}
+
+/**
+ *  tlvinfo_add_tlv
+ *
+ *  This function adds a TLV to the EEPROM, converting the value (a string) to
+ *  the format in which it will be stored in the EEPROM.
+ */
+#define MAX_TLV_VALUE_LEN   256
+static bool tlvinfo_add_tlv(u8 *eeprom, int tcode, char *strval)
+{
+	struct tlvinfo_header *eeprom_hdr = to_header(eeprom);
+	struct tlvinfo_tlv *eeprom_tlv;
+	int new_tlv_len = 0;
+	u32 value;
+	char data[MAX_TLV_VALUE_LEN];
+	int eeprom_index;
+
+	// Encode each TLV type into the format to be stored in the EERPOM
+	switch (tcode) {
+	case TLV_CODE_PRODUCT_NAME:
+	case TLV_CODE_PART_NUMBER:
+	case TLV_CODE_SERIAL_NUMBER:
+	case TLV_CODE_LABEL_REVISION:
+	case TLV_CODE_PLATFORM_NAME:
+	case TLV_CODE_ONIE_VERSION:
+	case TLV_CODE_MANUF_NAME:
+	case TLV_CODE_MANUF_COUNTRY:
+	case TLV_CODE_VENDOR_NAME:
+	case TLV_CODE_DIAG_VERSION:
+	case TLV_CODE_SERVICE_TAG:
+		strncpy(data, strval, MAX_TLV_VALUE_LEN);
+		new_tlv_len = min_t(size_t, MAX_TLV_VALUE_LEN, strlen(strval));
+		break;
+	case TLV_CODE_DEVICE_VERSION:
+		value = simple_strtoul(strval, NULL, 0);
+		if (value >= 256) {
+			printf("ERROR: Device version must be 255 or less. Value supplied: %u",
+			       value);
+			return false;
+		}
+		data[0] = value & 0xFF;
+		new_tlv_len = 1;
+		break;
+	case TLV_CODE_MAC_SIZE:
+		value = simple_strtoul(strval, NULL, 0);
+		if (value >= 65536) {
+			printf("ERROR: MAC Size must be 65535 or less. Value supplied: %u",
+			       value);
+			return false;
+		}
+		data[0] = (value >> 8) & 0xFF;
+		data[1] = value & 0xFF;
+		new_tlv_len = 2;
+		break;
+	case TLV_CODE_MANUF_DATE:
+		if (set_date(data, strval) != 0)
+			return false;
+		new_tlv_len = 19;
+		break;
+	case TLV_CODE_MAC_BASE:
+		if (set_mac(data, strval) != 0)
+			return false;
+		new_tlv_len = 6;
+		break;
+	case TLV_CODE_CRC_32:
+		printf("WARNING: The CRC TLV is set automatically and cannot be set manually.\n");
+		return false;
+	case TLV_CODE_VENDOR_EXT:
+	default:
+		if (set_bytes(data, strval, &new_tlv_len) != 0)
+			return false;
+		break;
+	}
+
+	// Is there room for this TLV?
+	if ((be16_to_cpu(eeprom_hdr->totallen) + ENT_SIZE + new_tlv_len) >
+			TLV_TOTAL_LEN_MAX) {
+		printf("ERROR: There is not enough room in the EERPOM to save data.\n");
+		return false;
+	}
+
+	// Add TLV at the end, overwriting CRC TLV if it exists
+	if (tlvinfo_find_tlv(eeprom, TLV_CODE_CRC_32, &eeprom_index))
+		eeprom_hdr->totallen =
+			cpu_to_be16(be16_to_cpu(eeprom_hdr->totallen) -
+					ENT_SIZE - 4);
+	else
+		eeprom_index = HDR_SIZE + be16_to_cpu(eeprom_hdr->totallen);
+	eeprom_tlv = to_entry(&eeprom[eeprom_index]);
+	eeprom_tlv->type = tcode;
+	eeprom_tlv->length = new_tlv_len;
+	memcpy(eeprom_tlv->value, data, new_tlv_len);
+
+	// Update the total length and calculate (add) a new CRC-32 TLV
+	eeprom_hdr->totallen = cpu_to_be16(be16_to_cpu(eeprom_hdr->totallen) +
+			ENT_SIZE + new_tlv_len);
+	update_crc(eeprom);
+
+	return true;
+}
+
+/**
+ *  set_mac
+ *
+ *  Converts a string MAC address into a binary buffer.
+ *
+ *  This function takes a pointer to a MAC address string
+ *  (i.e."XX:XX:XX:XX:XX:XX", where "XX" is a two-digit hex number).
+ *  The string format is verified and then converted to binary and
+ *  stored in a buffer.
+ */
+static int set_mac(char *buf, const char *string)
+{
+	char *p = (char *)string;
+	int   i;
+	int   err = 0;
+	char *end;
+
+	if (!p) {
+		printf("ERROR: NULL mac addr string passed in.\n");
+		return -1;
+	}
+
+	if (strlen(p) != 17) {
+		printf("ERROR: MAC address strlen() != 17 -- %zu\n", strlen(p));
+		printf("ERROR: Bad MAC address format: %s\n", string);
+		return -1;
+	}
+
+	for (i = 0; i < 17; i++) {
+		if ((i % 3) == 2) {
+			if (p[i] != ':') {
+				err++;
+				printf("ERROR: mac: p[%i] != :, found: `%c'\n",
+				       i, p[i]);
+				break;
+			}
+			continue;
+		} else if (!is_hex(p[i])) {
+			err++;
+			printf("ERROR: mac: p[%i] != hex digit, found: `%c'\n",
+			       i, p[i]);
+			break;
+		}
+	}
+
+	if (err != 0) {
+		printf("ERROR: Bad MAC address format: %s\n", string);
+		return -1;
+	}
+
+	/* Convert string to binary */
+	for (i = 0, p = (char *)string; i < 6; i++) {
+		buf[i] = p ? simple_strtoul(p, &end, 16) : 0;
+		if (p)
+			p = (*end) ? end + 1 : end;
+	}
+
+	if (!is_valid_ethaddr((u8 *)buf)) {
+		printf("ERROR: MAC address must not be 00:00:00:00:00:00, a multicast address or FF:FF:FF:FF:FF:FF.\n");
+		printf("ERROR: Bad MAC address format: %s\n", string);
+		return -1;
+	}
+
+	return 0;
+}
+
+/**
+ *  set_date
+ *
+ *  Validates the format of the data string
+ *
+ *  This function takes a pointer to a date string (i.e. MM/DD/YYYY hh:mm:ss)
+ *  and validates that the format is correct. If so the string is copied
+ *  to the supplied buffer.
+ */
+static int set_date(char *buf, const char *string)
+{
+	int i;
+
+	if (!string) {
+		printf("ERROR: NULL date string passed in.\n");
+		return -1;
+	}
+
+	if (strlen(string) != 19) {
+		printf("ERROR: Date strlen() != 19 -- %zu\n", strlen(string));
+		printf("ERROR: Bad date format (MM/DD/YYYY hh:mm:ss): %s\n",
+		       string);
+		return -1;
+	}
+
+	for (i = 0; string[i] != 0; i++) {
+		switch (i) {
+		case 2:
+		case 5:
+			if (string[i] != '/') {
+				printf("ERROR: Bad date format (MM/DD/YYYY hh:mm:ss): %s\n",
+				       string);
+				return -1;
+			}
+			break;
+		case 10:
+			if (string[i] != ' ') {
+				printf("ERROR: Bad date format (MM/DD/YYYY hh:mm:ss): %s\n",
+				       string);
+				return -1;
+			}
+			break;
+		case 13:
+		case 16:
+			if (string[i] != ':') {
+				printf("ERROR: Bad date format (MM/DD/YYYY hh:mm:ss): %s\n",
+				       string);
+				return -1;
+			}
+			break;
+		default:
+			if (!is_digit(string[i])) {
+				printf("ERROR: Bad date format (MM/DD/YYYY hh:mm:ss): %s\n",
+				       string);
+				return -1;
+			}
+			break;
+		}
+	}
+
+	strcpy(buf, string);
+	return 0;
+}
+
+/**
+ *  set_bytes
+ *
+ *  Converts a space-separated string of decimal numbers into a
+ *  buffer of bytes.
+ *
+ *  This function takes a pointer to a space-separated string of decimal
+ *  numbers (i.e. "128 0x55 0321") with "C" standard radix specifiers
+ *  and converts them to an array of bytes.
+ */
+static int set_bytes(char *buf, const char *string, int *converted_accum)
+{
+	char *p = (char *)string;
+	int   i;
+	uint  byte;
+
+	if (!p) {
+		printf("ERROR: NULL string passed in.\n");
+		return -1;
+	}
+
+	/* Convert string to bytes */
+	for (i = 0, p = (char *)string; (i < TLV_VALUE_MAX_LEN) && (*p != 0);
+			i++) {
+		while ((*p == ' ') || (*p == '\t') || (*p == ',') ||
+		       (*p == ';')) {
+			p++;
+		}
+		if (*p != 0) {
+			if (!is_digit(*p)) {
+				printf("ERROR: Non-digit found in byte string: (%s)\n",
+				       string);
+				return -1;
+			}
+			byte = simple_strtoul(p, &p, 0);
+			if (byte >= 256) {
+				printf("ERROR: The value specified is greater than 255: (%u) in string: %s\n",
+				       byte, string);
+				return -1;
+			}
+			buf[i] = byte & 0xFF;
+		}
+	}
+
+	if (i == TLV_VALUE_MAX_LEN && (*p != 0)) {
+		printf("ERROR: Trying to assign too many bytes (max: %d) in string: %s\n",
+		       TLV_VALUE_MAX_LEN, string);
+		return -1;
+	}
+
+	*converted_accum = i;
+	return 0;
+}
+
+static void show_tlv_devices(void)
+{
+	unsigned int dev;
+
+	for (dev = 0; dev < MAX_TLV_DEVICES; dev++)
+		if (tlv_devices[dev])
+			printf("TLV: %u%s\n", dev,
+			       (dev == current_dev) ? " (*)" : "");
+}
+
+static int find_tlv_devices(struct udevice **tlv_devices_p)
+{
+	int ret;
+	int count_dev = 0;
+	struct udevice *dev;
+
+	for (ret = uclass_first_device_check(UCLASS_I2C_EEPROM, &dev);
+			dev;
+			ret = uclass_next_device_check(&dev)) {
+		if (ret == 0)
+			tlv_devices_p[count_dev++] = dev;
+		if (count_dev >= MAX_TLV_DEVICES)
+			break;
+	}
+
+	return (count_dev == 0) ? -ENODEV : 0;
+}
+
+static struct udevice *find_tlv_device_by_index(int dev_num)
+{
+	struct udevice *local_tlv_devices[MAX_TLV_DEVICES] = {};
+	struct udevice **tlv_devices_p;
+	int ret;
+
+	if (gd->flags & (GD_FLG_RELOC | GD_FLG_SPL_INIT)) {
+		/* Assume BSS is initialized; use static data */
+		if (tlv_devices[dev_num])
+			return tlv_devices[dev_num];
+		tlv_devices_p = tlv_devices;
+	} else {
+		tlv_devices_p = local_tlv_devices;
+	}
+
+	ret = find_tlv_devices(tlv_devices_p);
+	if (ret == 0 && tlv_devices_p[dev_num])
+		return tlv_devices_p[dev_num];
+
+	return NULL;
+}
+
+/**
+ * read_tlv_eeprom - read the hwinfo from i2c EEPROM
+ */
+int read_tlv_eeprom(void *eeprom, int offset, int len, int dev_num)
+{
+	struct udevice *dev;
+
+	if (dev_num >= MAX_TLV_DEVICES)
+		return -EINVAL;
+
+	dev = find_tlv_device_by_index(dev_num);
+	if (!dev)
+		return -ENODEV;
+
+	return i2c_eeprom_read(dev, offset, eeprom, len);
+}
+
+/**
+ * write_tlv_eeprom - write the hwinfo to i2c EEPROM
+ */
+int write_tlv_eeprom(void *eeprom, int len)
+{
+	if (!(gd->flags & GD_FLG_RELOC))
+		return -ENODEV;
+	if (!tlv_devices[current_dev])
+		return -ENODEV;
+
+	return i2c_eeprom_write(tlv_devices[current_dev], 0, eeprom, len);
+}
+
+int read_tlvinfo_tlv_eeprom(void *eeprom, struct tlvinfo_header **hdr,
+			    struct tlvinfo_tlv **first_entry, int dev_num)
+{
+	int ret;
+	struct tlvinfo_header *tlv_hdr;
+	struct tlvinfo_tlv *tlv_ent;
+
+	/* Read TLV header */
+	ret = read_tlv_eeprom(eeprom, 0, HDR_SIZE, dev_num);
+	if (ret < 0)
+		return ret;
+
+	tlv_hdr = eeprom;
+	if (!is_valid_tlvinfo_header(tlv_hdr))
+		return -EINVAL;
+
+	/* Read TLV entries */
+	tlv_ent = to_entry(&tlv_hdr[1]);
+	ret = read_tlv_eeprom(tlv_ent, HDR_SIZE,
+			      be16_to_cpu(tlv_hdr->totallen), dev_num);
+	if (ret < 0)
+		return ret;
+	if (!is_checksum_valid(eeprom))
+		return -EINVAL;
+
+	*hdr = tlv_hdr;
+	*first_entry = tlv_ent;
+
+	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;
+	int eeprom_index;
+	struct tlvinfo_tlv *eeprom_tlv;
+	int maccount;
+	u8 macbase[6];
+	struct tlvinfo_header *eeprom_hdr = to_header(eeprom);
+
+	puts("EEPROM: ");
+
+	if (read_eeprom(eeprom)) {
+		printf("Read failed.\n");
+		return -1;
+	}
+
+	maccount = 1;
+	if (tlvinfo_find_tlv(eeprom, TLV_CODE_MAC_SIZE, &eeprom_index)) {
+		eeprom_tlv = to_entry(&eeprom[eeprom_index]);
+		maccount = (eeprom_tlv->value[0] << 8) | eeprom_tlv->value[1];
+	}
+
+	memcpy(macbase, "\0\0\0\0\0\0", 6);
+	if (tlvinfo_find_tlv(eeprom, TLV_CODE_MAC_BASE, &eeprom_index)) {
+		eeprom_tlv = to_entry(&eeprom[eeprom_index]);
+		memcpy(macbase, eeprom_tlv->value, 6);
+	}
+
+	for (i = 0; i < maccount; i++) {
+		if (is_valid_ethaddr(macbase)) {
+			char ethaddr[18];
+			char enetvar[11];
+
+			sprintf(ethaddr, "%02X:%02X:%02X:%02X:%02X:%02X",
+				macbase[0], macbase[1], macbase[2],
+				macbase[3], macbase[4], macbase[5]);
+			sprintf(enetvar, i ? "eth%daddr" : "ethaddr", i);
+			/* Only initialize environment variables that are blank
+			 * (i.e. have not yet been set)
+			 */
+			if (!env_get(enetvar))
+				env_set(enetvar, ethaddr);
+
+			macbase[5]++;
+			if (macbase[5] == 0) {
+				macbase[4]++;
+				if (macbase[4] == 0) {
+					macbase[3]++;
+					if (macbase[3] == 0) {
+						macbase[0] = 0;
+						macbase[1] = 0;
+						macbase[2] = 0;
+					}
+				}
+			}
+		}
+	}
+
+	printf("%s v%u len=%u\n", eeprom_hdr->signature, eeprom_hdr->version,
+	       be16_to_cpu(eeprom_hdr->totallen));
+
+	return 0;
+}
+
+/**
+ *  populate_serial_number - read the serial number from EEPROM
+ *
+ *  This function reads the serial number from the EEPROM and sets the
+ *  appropriate environment variable.
+ *
+ *  The environment variable is only set if it has not been set
+ *  already.  This ensures that any user-saved variables are never
+ *  overwritten.
+ *
+ *  This function must be called after relocation.
+ */
+int populate_serial_number(void)
+{
+	char serialstr[257];
+	int eeprom_index;
+	struct tlvinfo_tlv *eeprom_tlv;
+
+	if (env_get("serial#"))
+		return 0;
+
+	if (read_eeprom(eeprom)) {
+		printf("Read failed.\n");
+		return -1;
+	}
+
+	if (tlvinfo_find_tlv(eeprom, TLV_CODE_SERIAL_NUMBER, &eeprom_index)) {
+		eeprom_tlv = to_entry(&eeprom[eeprom_index]);
+		memcpy(serialstr, eeprom_tlv->value, eeprom_tlv->length);
+		serialstr[eeprom_tlv->length] = 0;
+		env_set("serial#", serialstr);
+	}
+
+	return 0;
+}