Add Omnia mcutool utility

This program interacts with Omnia MCU over I2C bus. It displays version
of the MCU firmware - both bootloader and application parts (which are
the git hashes compiled into the images) and flash application image
to the MCU EEPROM.

mcutool/README

+This program interacts with Omnia MCU over I2C bus. It displays version
+of the MCU firmware - both bootloader and application parts (which are
+the git hashes compiled into the images) and flash application image
+to the MCU EEPROM.
+
+Copyright (C) 2016 CZ.NIC
+

mcutool/mcutool.c

+/*
+ * This program interacts with Omnia MCU over I2C bus. It displays version
+ * of the MCU firmware - both bootloader and application parts (which are
+ * the git hashes compiled into the images) and flash application image
+ * to the MCU EEPROM.
+ *
+ * Copyright (C) 2016 CZ.NIC
+ *
+ * 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.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <linux/i2c-dev.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <time.h>
+#include <getopt.h>
+
+#define DEV_NAME 	"/dev/i2c-1"
+#define PAGE_SIZE 	128 /* bytes in page mode I2C transfer, 128 for MCU */
+#define ADDR_SIZE	2 /* 2 bytes address length in I2C transfer */
+#define DEV_ADDR_BOOT 	0x2c /* 0x2c for MCU in bootloader */
+#define DEV_ADDR_APP 	0x2a /* 0x2a for MCU in application */
+#define FLASH_SIZE 	43008 /* flash size, 42k for MCU */
+#define WRITE_DELAY 	20 /* ms */
+#define RETRY 		3
+
+#define FILE_CMP_OK	0xBB /* bootloader flash protocol code: flash OK */
+#define FILE_CMP_ERROR	0xDD /* bootloader flash protocol code: flash failed */
+#define ADDR_CMP	0xFFFF /* bootloader flash protocol code addr */
+
+#define CMD_CONTROL		0x02 /* app protocol cmd */
+#define CMD_CONTROL_FLASH	0x8080 /* app protocol cmd argument */
+#define CMD_VERSION_APP		0x0A /* app protocol cmd */
+#define CMD_VERSION_BOOT	0x0E /* app protocol cmd */
+#define VERSION_HASHLEN		20 /* 20 bytes of SHA-1 git hash */
+#define BOOTLOADER_TRANS_DELAY	1 /* Bootloader transition delay */
+
+
+int open_i2c(int addr) {
+	int fd;
+
+	if ((fd = open(DEV_NAME, O_RDWR)) < 0) {
+		perror("Failed to open I2C bus");
+		exit(EXIT_FAILURE);
+	}
+
+	if (ioctl(fd, I2C_SLAVE, addr) < 0) {
+		perror("Failed to acquire bus access and/or talk to slave.");
+		exit(EXIT_FAILURE);
+	}
+
+	return fd;
+}
+
+void set_addr(char buf[], int addr) {
+	buf[0] = (addr & 0xFF00) >> 8;
+	buf[1] = (addr & 0xFF);
+}
+
+void writebuff(char *buff, int startaddr, int len) {
+	int size, offset, fd, r, w;
+	char b[PAGE_SIZE+ADDR_SIZE];
+
+	fd = open_i2c(DEV_ADDR_BOOT);
+
+	printf("Writing data ");
+	fflush(stdout);
+	for (offset=0; offset<len; offset+=PAGE_SIZE) {
+		set_addr(b, startaddr+offset);
+		size = len-offset < PAGE_SIZE ? len-offset : PAGE_SIZE;
+
+		memcpy(b+ADDR_SIZE, buff+offset, size);
+
+		for (r=1; r <= RETRY; r++) {
+			w = write(fd, b, size+ADDR_SIZE);
+			nanosleep((const struct timespec[]){{0,
+					(WRITE_DELAY*1000000L)}}, NULL);
+
+			if (w != size+ADDR_SIZE) {
+				if (r == RETRY) {
+					perror("I2C write operation failed");
+					exit(EXIT_FAILURE);
+				}
+			} else
+				break; /* Retry loop. */
+		}
+
+		printf("w");
+		fflush(stdout);
+	}
+
+	close(fd);
+
+	printf("\n");
+	fflush(stdout);
+}
+
+int readbuff(char *buff, int startaddr, int len) {
+	int size, offset, fd, rb, readtotal=0;
+        char b[ADDR_SIZE];
+
+	fd = open_i2c(DEV_ADDR_BOOT);
+
+        for (offset=0; offset<len; offset+=PAGE_SIZE) {
+		set_addr(b, startaddr+offset);
+		size = len-offset < PAGE_SIZE ? len-offset : PAGE_SIZE;
+
+		if (write(fd, b, ADDR_SIZE) != 2) {
+                        perror("I2C write operation failed");
+                        exit(EXIT_FAILURE);
+                }
+	
+		rb = read(fd, buff+offset, size);
+		if (rb < 0) {
+			perror("I2C read operation failed");
+			exit(EXIT_FAILURE);
+		}
+
+		readtotal+=rb;
+
+		printf("r");
+		fflush(stdout);
+
+		if (rb < size)
+			break;
+	}
+
+	close(fd);
+
+	printf("\n");
+	fflush(stdout);
+
+	return readtotal;
+}
+
+void read_version(char version[], char cmd) {
+	int rb, fd;
+
+	fd = open_i2c(DEV_ADDR_APP);
+
+	if (write(fd, &cmd, 1) != 1) {
+		perror("I2C write operation failed");
+	        exit(EXIT_FAILURE);
+	}
+
+	rb = read(fd, version, VERSION_HASHLEN);
+	if (rb < 0) {
+		perror("I2C read operation failed");
+		exit(EXIT_FAILURE);
+	}
+
+	close(fd);
+}
+
+void print_version(char version[]) {
+	int i;
+	for (i = 0; i < VERSION_HASHLEN; i++)
+                printf("%02x", version[i]);
+
+        printf("\n");
+}
+
+void print_app_version(void) {
+	char buf[VERSION_HASHLEN];
+
+	read_version(buf, CMD_VERSION_APP);
+	printf("Application version: ");
+	print_version(buf);
+}
+
+void print_bootloader_version(void) {
+	char buf[VERSION_HASHLEN];
+
+	read_version(buf, CMD_VERSION_BOOT);
+	printf("Bootloader version:  ");
+	print_version(buf);
+}
+
+void write_cmp_result(char result)
+{
+	writebuff(&result, ADDR_CMP, 1);
+}
+
+void goto_bootloader(void) {
+	int fd;
+	char cmd[3];
+
+	printf("Switching MCU to bootloader...\n");
+
+	cmd[0] = CMD_CONTROL;
+	cmd[1] = (CMD_CONTROL_FLASH & 0xFF00) >> 8;
+	cmd[2] = (CMD_CONTROL_FLASH & 0xFF);
+
+	fd = open_i2c(DEV_ADDR_APP);
+
+	if (write(fd, cmd, 3) != 3) {
+		perror("I2C write operation failed");
+	        exit(EXIT_FAILURE);
+	}
+
+	close(fd);
+
+	sleep(BOOTLOADER_TRANS_DELAY);
+}
+
+void flash_file(char *filename) {
+	int fd, size, rsize;
+	char buff[FLASH_SIZE], rbuff[FLASH_SIZE], result;
+
+	if ((fd = open(filename, O_RDONLY)) < 0) {
+		perror("Failed to open file");
+		exit(EXIT_FAILURE);
+	}
+
+	if((size=read(fd, buff, FLASH_SIZE))<=0) {
+		perror("Failed to read file");
+		exit(EXIT_FAILURE);
+	}
+
+	close(fd);
+
+	printf("File %s (%d B):", filename, size);
+	writebuff(buff, 0, size);
+
+	printf("Readback from MCU: ");
+	rsize = readbuff(rbuff, 0, size);
+
+	if ((rsize != size) || memcmp(buff, rbuff, size)) {
+		printf("WARNING: Readback failed!\n");
+		result = FILE_CMP_ERROR;
+	} else {
+		printf("SUCCESS: Readback OK.\n");
+		result = FILE_CMP_OK;
+	}
+
+	write_cmp_result(result);
+}
+
+void usage(void) {
+	printf("mcu -- Turris Omnia MCU flash utility\n");
+	printf("Usage: mcu [COMMAND] [FILE].\n");
+	printf("  -h : Print this help.\n");
+	printf("  -v : Print version of MCU bootloader and app.\n");
+	printf("  -f [FILE] : Flash application image.\n");
+	printf("  -r [FILE] : Flash application image. Rescue in bootloader.\n");
+}
+
+int main(int argc, char *argv[]) {
+	int opt;
+
+	opt = getopt(argc, argv, "hvf:r:");
+	switch (opt) {
+		case 'h':
+			usage();
+			break;
+		case 'v':
+			print_bootloader_version();
+			print_app_version();
+			break;
+		case 'f':
+			goto_bootloader();
+		case 'r':
+			flash_file(optarg);
+			printf("Writing finished. Please reboot!\n");
+			break;
+		default:
+			printf("Unknown option.\n\n");
+			usage();
+	}
+
+	return EXIT_SUCCESS;
+}
+