eepromread: simple program to view eeprom contents

This program uses the i2c /dev interface to read the
contents of EEPROMs and display it to the user in
HEX and ASCII. It also has a mode that can display
data in label:value pairs. That mode is used for
board detection in the rc script to start the right
i2c drivers for the board.

Change-Id: I0bf5b13ffab5a89533c762d6881a145cf7f14914

commands/Makefile

@@ -38,4 +38,9 @@ SUBDIR+=	atnormalize dosread fdisk loadfont \
 	autopart part partition playwave  \
 	recwave repartition screendump
 .endif
+
+.if ${MACHINE_ARCH} == "earm"
+SUBDIR+=	eepromread
+.endif
+
 .include <bsd.subdir.mk>

commands/eepromread/Makefile

@@ -0,0 +1,5 @@
+PROG=	eepromread
+SRCS=	eepromread.c eepromread.h board_info.c
+MAN=	eepromread.1
+
+.include <bsd.prog.mk>

commands/eepromread/board_info.c

@@ -0,0 +1,87 @@
+#include <minix/i2c.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "eepromread.h"
+
+/*
+ * Attempt to read the board info from an eeprom on this board.
+ * Currently only supports the BeagleBone and BeagleBone Black.
+ * In the future, this could be expanded to support cape EEPROMs.
+ */
+
+static int board_info_beaglebone(int fd, i2c_addr_t address);
+
+/* Memory Layout of the BeagleBone and BeagleBone Black EEPROM */
+typedef struct beaglebone_info
+{
+	uint8_t magic_number[4];	/* Should be 0xaa 0x55 0x33 0xee */
+	char board_name[8];	/* Warning: strings not NULL terminated */
+	char version[4];
+	char serial_number[12];
+	char config[32];	/* All 0x00 on BeagleBone White */
+	char mac_addrs[3][6];	/* Not set on BeagleBone White */
+} beaglebone_info_t;
+
+static int
+board_info_beaglebone(int fd, i2c_addr_t address)
+{
+	int r;
+	int i, j;
+	char s[33];
+	beaglebone_info_t boneinfo;
+
+	r = eeprom_read(fd, address, 0x0000, &boneinfo,
+	    sizeof(beaglebone_info_t));
+	if (r == -1) {
+		fprintf(stderr, "Failed to read BeagleBone info r=%d\n", r);
+		return -1;
+	}
+
+	fprintf(stdout, "%-16s: 0x%x%x%x%x\n", "MAGIC_NUMBER",
+	    boneinfo.magic_number[0], boneinfo.magic_number[1],
+	    boneinfo.magic_number[2], boneinfo.magic_number[3]);
+
+	memset(s, '\0', 33);
+	memcpy(s, boneinfo.board_name, 8);
+	fprintf(stdout, "%-16s: %s\n", "BOARD_NAME", s);
+
+	memset(s, '\0', 33);
+	memcpy(s, boneinfo.version, 4);
+	fprintf(stdout, "%-16s: %s\n", "VERSION", s);
+
+	memcpy(s, boneinfo.serial_number, 12);
+	fprintf(stdout, "%-16s: %s\n", "SERIAL_NUMBER", s);
+
+	return 0;
+}
+
+int
+board_info(int fd, i2c_addr_t address)
+{
+	int r;
+	uint8_t magic_number[4];
+
+	r = eeprom_read(fd, address, 0x0000, &magic_number, 4);
+	if (r == -1) {
+		printf("%-16s: %s\n", "BOARD_NAME", "UNKNOWN");
+		return 0;
+	}
+
+	if (magic_number[0] == 0xaa && magic_number[1] == 0x55 &&
+	    magic_number[2] == 0x33 && magic_number[3] == 0xee) {
+		board_info_beaglebone(fd, address);
+	} else {
+		printf("%-16s: %s\n", "BOARD_NAME", "UNKNOWN");
+	}
+
+	return 0;
+}

commands/eepromread/eepromread.1

@@ -0,0 +1,46 @@
+.TH EEPROMREAD 1
+.SH NAME
+eepromread \- read data from an EEPROM
+.SH SYNOPSIS
+\fBeepromread\fR [\fB\-i\fR] [\fB\-f\fR \fIdev\fR] [\fB\-a\fR \fIslave_addr\fR]
+.br
+.de FL
+.TP
+\\fB\\$1\\fR
+\\$2
+..
+.de EX
+.TP 20
+\\fB\\$1\\fR
+# \\$2
+..
+.SH OPTIONS 
+.TP 5
+.B \-i
+# interpret the data on the EEPROM and display it as a set of fields.
+.TP 5
+.B \-f
+# Use \fIdevice\fR instead of \fI/dev/i2c-1\fR.
+.TP 5
+.B \-a
+# Use \fIslave_address\fR instead of \fI0x50\fR.
+.SH EXAMPLES
+.TP 20
+.B eepromread -i
+# display the contents of the EEPROM as a list of label:value pairs.
+.TP 20
+.B eepromread
+# display the first 256 bytes of the EEPROM in HEX and ASCII.
+.TP 20
+.B eepromread -f /dev/i2c-3 -a 0x54
+# display the first 256 bytes of the EEPROM on I2C bus 3, slave address 0x54.
+.SH DESCRIPTION
+.PP
+\fIeepromread\fR is a simple tool for viewing the contents of an EEPROM.
+For EEPROM data that is in a specific format that this program knows how to
+detect, \fIeepromread\fR can properly format each of the fields and display
+the information via the \fI-i\fR command line option.
+.SH NOTES
+If the \fIcat24c256\fR driver has claimed the EEPROM device that this
+program is attempting to read from, then this program will fail. Once
+a driver claims an I2C device, the driver has exclusive access.

commands/eepromread/eepromread.c

@@ -0,0 +1,205 @@
+#include <minix/i2c.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "eepromread.h"
+
+static int __eeprom_read32(int fd, i2c_addr_t addr, uint16_t memaddr,
+    void *buf, size_t buflen);
+static int eeprom_dump(int fd, i2c_addr_t addr);
+
+#define DEFAULT_I2C_DEVICE "/dev/i2c-1"
+#define DEFAULT_I2C_ADDRESS 0x50
+
+/*
+ * The /dev interface only supports 32 byte reads/writes and the EEPROM is
+ * larger, so to read the whole EEPROM, the task is broken down into 32 byte
+ * chunks in eeprom_read(). __eeprom_read32() does the actual ioctl() to do
+ * the read.
+ *
+ * A future enhancement might be to add support for the /dev/eeprom interface
+ * and if one way fails, fall back to the other. /dev/eeprom can fail if the
+ * eeprom driver isn't running and /dev/i2c can fail if the eeprom driver
+ * claimed the eeprom device.
+ */
+
+static int
+__eeprom_read32(int fd, i2c_addr_t addr, uint16_t memaddr, void *buf,
+    size_t buflen)
+{
+	int r;
+	minix_i2c_ioctl_exec_t ioctl_exec;
+
+	if (buflen > I2C_EXEC_MAX_BUFLEN || buf == NULL
+	    || ((memaddr + buflen) < memaddr)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	memset(&ioctl_exec, '\0', sizeof(minix_i2c_ioctl_exec_t));
+
+	ioctl_exec.iie_op = I2C_OP_READ_WITH_STOP;
+	ioctl_exec.iie_addr = addr;
+
+	/* set the address to read from */
+	ioctl_exec.iie_cmd[0] = ((memaddr >> 8) & 0xff);
+	ioctl_exec.iie_cmd[1] = (memaddr & 0xff);
+	ioctl_exec.iie_cmdlen = 2;
+
+	ioctl_exec.iie_buflen = buflen;
+
+	r = ioctl(fd, MINIX_I2C_IOCTL_EXEC, &ioctl_exec);
+	if (r == -1) {
+		return -1;
+	}
+
+	/* call was good, copy results to caller's buffer */
+	memcpy(buf, ioctl_exec.iie_buf, buflen);
+
+	return 0;
+}
+
+int
+eeprom_read(int fd, i2c_addr_t addr, uint16_t memaddr, void *buf,
+    size_t buflen)
+{
+	int r;
+	uint16_t i;
+
+	if (buf == NULL || ((memaddr + buflen) < memaddr)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	for (i = 0; i < buflen; i += 32) {
+
+		r = __eeprom_read32(fd, addr, memaddr + i, buf + i,
+		    ((buflen - i) < 32) ? (buflen - i) : 32);
+		if (r == -1) {
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Read 256 bytes and print it to the screen in HEX and ASCII.
+ */
+static int
+eeprom_dump(int fd, i2c_addr_t addr)
+{
+	int i, j, r;
+	uint8_t buf[256];
+
+	memset(buf, '\0', 256);
+
+	r = eeprom_read(fd, addr, 0x0000, buf, 256);
+	if (r == -1) {
+		return r;
+	}
+
+	/* print table header */
+	for (i = 0; i < 2; i++) {
+		printf("   ");
+		for (j = 0x0; j <= 0xf; j++) {
+			if (i == 0) {
+				printf("  ");
+			}
+			printf("%x", j);
+		}
+	}
+	printf("\n");
+
+	/* print table data */
+	for (i = 0x00; i < 0xff; i += 0x10) {
+
+		/* row label */
+		printf("%02x:", i);
+
+		/* row data (in hex) */
+		for (j = 0x0; j <= 0xf; j++) {
+			printf(" %02x", buf[i + j]);
+		}
+
+		printf("   ");
+
+		/* row data (in ASCII) */
+		for (j = 0x0; j <= 0xf; j++) {
+			if (isprint(buf[i + j])) {
+				printf("%c", buf[i + j]);
+			} else {
+				printf(".");
+			}
+		}
+
+		printf("\n");
+	}
+
+	return 0;
+}
+
+int
+main(int argc, char *argv[])
+{
+	int r, fd;
+	int ch, iflag = 0;
+	char *device = DEFAULT_I2C_DEVICE;
+	i2c_addr_t address = DEFAULT_I2C_ADDRESS;
+
+	setprogname(*argv);
+
+	while ((ch = getopt(argc, argv, "a:f:i")) != -1) {
+		switch (ch) {
+		case 'a':
+			address = strtol(optarg, NULL, 0x10);
+			break;
+		case 'f':
+			device = optarg;
+			break;
+		case 'i':
+			iflag = 1;
+			break;
+		default:
+			break;
+		}
+	}
+
+	fd = open(device, O_RDWR);
+	if (fd == -1) {
+		fprintf(stderr, "open(): %s\n", strerror(errno));
+		return 1;
+	}
+
+	if (iflag == 1) {
+		r = board_info(fd, address);
+		if (r == -1) {
+			fprintf(stderr, "board_info(): %s\n", strerror(errno));
+			return 1;
+		}
+	} else {
+		r = eeprom_dump(fd, address);
+		if (r == -1) {
+			fprintf(stderr, "eeprom_dump(): %s\n", strerror(errno));
+			return 1;
+		}
+	}
+
+	r = close(fd);
+	if (r == -1) {
+		fprintf(stderr, "close(): %s\n", strerror(errno));
+		return 1;
+	}
+
+	return 0;
+}
+

commands/eepromread/eepromread.h

@@ -0,0 +1,8 @@
+#ifndef __EEPROMREAD_H
+#define __EEPROMREAD_H
+
+int eeprom_read(int fd, i2c_addr_t addr, uint16_t memaddr, void *buf,
+								size_t buflen);
+int board_info(int fd, i2c_addr_t address);
+
+#endif /* __EEPROMREAD_H */

distrib/sets/lists/minix/md.evbarm

@@ -10,6 +10,7 @@
 ./multiboot/mod10_vm			minix-sys
 ./multiboot/mod11_pfs			minix-sys
 ./multiboot/mod12_init			minix-sys
+./usr/bin/eepromread			minix-sys
 ./usr/include/arm			minix-sys
 ./usr/include/arm/aeabi.h		minix-sys
 ./usr/include/arm/ansi.h		minix-sys
@@ -101,6 +102,7 @@
 ./usr/lib/libi2cdriver_pic.a		minix-sys
 ./usr/lib/libpadconf.a			minix-sys
 ./usr/lib/libpadconf_pic.a		minix-sys
+./usr/man/man1/eepromread.1		minix-sys
 ./usr/mdec				minix-sys
 ./usr/sbin/cat24c256			minix-sys
 ./usr/sbin/fb				minix-sys

etc/usr/rc

@@ -194,6 +194,30 @@ start)
 			-args instance=${bus}
 	done
 	echo .
+
+	BOARD_NAME=`eepromread -i | sed -n 's/^BOARD_NAME      : \(.*\)$/\1/p'`
+	case "${BOARD_NAME}" in
+		A335BONE)
+			echo "Detected BeagleBone"
+			echo -n "Starting i2c device drivers: "
+			test -e /dev/eepromb1s50 || (cd /dev && MAKEDEV eepromb1s50)
+			up cat24c256 -dev /dev/eepromb1s50 \
+				-label cat24c256.1.50 -args 'bus=1 address=0x50'
+			;;
+		A335BNLT)
+			echo "Detected BeagleBone Black"
+			echo -n "Starting i2c device drivers: "
+			test -e /dev/eepromb1s50 || (cd /dev && MAKEDEV eepromb1s50)
+			up cat24c256 -dev /dev/eepromb1s50 \
+				-label cat24c256.1.50 -args 'bus=1 address=0x50'
+			;;
+		UNKNOWN)
+			echo "Unable to detect board -- assuming BeagleBoard-xM"
+			echo -n "Starting i2c device drivers: "
+			;;
+	esac
+
+	echo .
     fi
 
     if [ "$net" ]