[OpenWrt-Devel] [RFC 1/3] firmware-utils mkmerakifw: firmware generator for Z1

Christian Lamparter chunkeey at googlemail.com
Tue Mar 8 18:14:40 EST 2016


This patch adds firmware generation tool for Cisco's Z1

Signed-off-by: Christian Lamparter <chunkeey at googlemail.com>
---
 tools/firmware-utils/src/mkmerakifw.c | 313 ++++++++++++++++++++++++++++------
 1 file changed, 258 insertions(+), 55 deletions(-)

diff --git a/tools/firmware-utils/src/mkmerakifw.c b/tools/firmware-utils/src/mkmerakifw.c
index 241bb33..1a0d79a 100644
--- a/tools/firmware-utils/src/mkmerakifw.c
+++ b/tools/firmware-utils/src/mkmerakifw.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2015 Thomas Hebb <tommyhebb at gmail.com>
+ * Copyright (C) 2016 Christian Lamparter <chunkeey at googlemail.com>
  *
  * The format of the header this tool generates was first documented by
  * Chris Blake <chrisrblake93 (at) gmail.com> in a shell script of the
@@ -7,6 +8,11 @@
  * original script can be found at:
  * <https://github.com/riptidewave93/meraki-partbuilder>
  *
+ * Support for the old header format, which is used by the Cisco Z1 AP
+ * has been reverse engineered from the nandloader's nand_load_bk function.
+ * The original code is part of Cisco's GPL code and can be found at:
+ * <https://github.com/riptidewave93/meraki-linux>
+ *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published
  * by the Free Software Foundation.
@@ -18,6 +24,7 @@
 #include <stdbool.h>
 #include <string.h>
 #include <libgen.h>
+#include <endian.h>
 #include <getopt.h>
 #include <errno.h>
 #include <arpa/inet.h>
@@ -35,24 +42,51 @@
 #define HDR_OFF_FILLER		36
 #define HDR_OFF_STATICHASH	40
 
+#define OLD_HDR_LENGTH		0x00000020
+#define OLD_HDR_OFF_MAGIC1	0
+#define OLD_HDR_OFF_LOAD_ADDR	4
+#define OLD_HDR_OFF_IMAGELEN	8
+#define OLD_HDR_OFF_ENTRY	12
+#define OLD_HDR_OFF_CHECKSUM	16
+#define OLD_HDR_OFF_FILLER0	20
+#define OLD_HDR_OFF_FILLER1	24
+#define OLD_HDR_OFF_FILLER2	28
+
+enum header_type_t {
+	MERAKI_OLD,
+	MERAKI_NEW,
+};
+
 struct board_info {
-	uint32_t magic;
-	uint32_t imagelen;
-	unsigned char statichash[20];
+	enum header_type_t header_type;
 	char *id;
 	char *description;
+	uint32_t magic;
+	uint32_t imagelen;
+
+	union {
+		struct {
+			unsigned char statichash[20];
+		};
+		struct {
+			uint32_t load_addr;
+			uint32_t entry;
+		};
+	};
 };
 
 /*
  * Globals
  */
 static char *progname;
+static bool strip_padding;
 
 static char *board_id;
 static const struct board_info *board;
 
 static const struct board_info boards[] = {
 	{
+		.header_type	= MERAKI_NEW,
 		.id		= "mr18",
 		.description	= "Meraki MR18 Access Point",
 		.magic		= 0x8e73ed8a,
@@ -62,6 +96,14 @@ static const struct board_info boards[] = {
 				   0xbf, 0xef, 0x95, 0x60, 0x18,
 				   0x90, 0xaf, 0xd8, 0x07, 0x09},
 	}, {
+		.header_type	= MERAKI_OLD,
+		.id		= "z1",
+		.description	= "Meraki Z1 Access Point",
+		.magic		= 0x4d495053,
+		.imagelen	= 0x007e0000,
+		.load_addr	= 0x80060000,
+		.entry		= 0x80060000
+	}, {
 		/* terminating entry */
 	}
 };
@@ -121,23 +163,220 @@ static void usage(int status)
 	exit(status);
 }
 
-void writel(unsigned char *buf, size_t offset, uint32_t value)
+static void writel(unsigned char *buf, size_t offset, uint32_t value)
 {
-	value = htonl(value);
+	value = htobe32(value);
 	memcpy(buf + offset, &value, sizeof(uint32_t));
 }
 
-int main(int argc, char *argv[])
+static int meraki_new(const struct board_info *board, const size_t klen,
+		      FILE *out, FILE *in)
 {
-	int ret = EXIT_FAILURE;
-	long klen;
-	size_t kspace;
 	unsigned char *kernel;
+	unsigned char *buf;
 	size_t buflen;
+	size_t kspace;
+
+	size_t rc;
+	buflen = board->imagelen;
+	kspace = buflen - HDR_LENGTH;
+
+	if (klen > kspace) {
+		ERR("kernel file is too big - max size: 0x%08lX\n", kspace);
+		return EXIT_FAILURE;
+	}
+
+	/* If requested, resize buffer to remove padding */
+	if (strip_padding)
+		buflen = klen + HDR_LENGTH;
+
+	/* Allocate and initialize buffer for final image */
+	buf = malloc(buflen);
+	if (buf == NULL) {
+		ERRS("no memory for buffer: %s\n");
+		return EXIT_FAILURE;
+	}
+	memset(buf, PADDING_BYTE, buflen);
+
+	/* Load kernel */
+	kernel = buf + HDR_LENGTH;
+	fread(kernel, klen, 1, in);
+
+	/* Write magic values and filler */
+	writel(buf, HDR_OFF_MAGIC1, board->magic);
+	writel(buf, HDR_OFF_MAGIC2, board->magic);
+	writel(buf, HDR_OFF_FILLER, 0);
+
+	/* Write header and image length */
+	writel(buf, HDR_OFF_HDRLEN, HDR_LENGTH);
+	writel(buf, HDR_OFF_IMAGELEN, klen);
+
+	/* Write checksum and static hash */
+	sha1_csum(kernel, klen, buf + HDR_OFF_CHECKSUM);
+	memcpy(buf + HDR_OFF_STATICHASH, board->statichash, 20);
+
+	rc = fwrite(buf, buflen, 1, out);
+
+	free(buf);
+
+	return rc == 1 ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+static const uint32_t crc32_table[] = {
+	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
+	0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
+	0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+	0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
+	0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+	0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+	0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
+	0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
+	0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+	0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+	0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
+	0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+	0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
+	0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
+	0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+	0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
+	0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
+	0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+	0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
+	0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+	0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+	0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
+	0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
+	0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+	0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+	0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
+	0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+	0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
+	0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
+	0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+	0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
+	0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
+	0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+	0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
+	0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+	0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+	0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
+	0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
+	0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+	0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+	0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
+	0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+	0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
+	0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
+	0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+	0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
+	0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
+	0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+	0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
+	0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+	0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+	0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
+	0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
+	0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+	0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+	0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
+	0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+	0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
+	0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
+	0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+	0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
+	0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
+	0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
+};
+
+static inline uint32_t crc32_accumulate_8(const uint32_t crc, const uint8_t ch)
+{
+	return crc32_table[(crc ^ ch) & 0xff] ^ (crc >> 8);
+}
+
+static void crc32_csum(uint8_t *buf, const size_t len)
+{
+	uint32_t crc;
+	size_t i;
+
+	crc = ~0;
+	for (i = 0; i < len; i += 4) {
+		crc = crc32_accumulate_8(crc, buf[i + 3]);
+		crc = crc32_accumulate_8(crc, buf[i + 2]);
+		crc = crc32_accumulate_8(crc, buf[i + 1]);
+		crc = crc32_accumulate_8(crc, buf[i]);
+	}
+	crc = ~crc;
+
+	writel(buf, OLD_HDR_OFF_CHECKSUM, crc);
+}
+
+
+static int meraki_old(const struct board_info *board, const size_t klen,
+		      FILE *out, FILE *in)
+{
+	unsigned char *kernel;
 	unsigned char *buf;
-	bool strip_padding = false;
+	size_t buflen;
+	size_t kspace;
+
+	size_t rc;
+	buflen = board->imagelen;
+	kspace = buflen - OLD_HDR_LENGTH;
+
+	if (klen > kspace) {
+		ERR("kernel file is too big - max size: 0x%08lX\n", kspace);
+		return EXIT_FAILURE;
+	}
+
+	/* If requested, resize buffer to remove padding */
+	if (strip_padding)
+		buflen = klen + OLD_HDR_LENGTH;
+
+	/* Allocate and initialize buffer for final image */
+	buf = malloc(buflen);
+	if (buf == NULL) {
+		ERRS("no memory for buffer: %s\n");
+		return EXIT_FAILURE;
+	}
+	memset(buf, PADDING_BYTE, buflen);
+
+	/* Load kernel */
+	kernel = buf + OLD_HDR_LENGTH;
+	fread(kernel, klen, 1, in);
+
+	/* Write magic values and filler */
+	writel(buf, OLD_HDR_OFF_MAGIC1, board->magic);
+	writel(buf, OLD_HDR_OFF_FILLER0, 0);
+	writel(buf, OLD_HDR_OFF_FILLER1, 0);
+	writel(buf, OLD_HDR_OFF_FILLER2, 0);
+
+	/* Write load and kernel entry point address */
+	writel(buf, OLD_HDR_OFF_LOAD_ADDR, board->load_addr);
+	writel(buf, OLD_HDR_OFF_ENTRY, board->entry);
+
+	/* Write header and image length */
+	writel(buf, OLD_HDR_OFF_IMAGELEN, klen);
+
+	/* this gets replaced later, after the checksum has been calculated */
+	writel(buf, OLD_HDR_OFF_CHECKSUM, 0);
+
+	/* Write checksum */
+	crc32_csum(buf, klen + OLD_HDR_LENGTH);
+
+	rc = fwrite(buf, buflen, 1, out);
+
+	free(buf);
+
+	return rc == 1 ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+int main(int argc, char *argv[])
+{
+	int ret = EXIT_FAILURE;
 	char *ofname = NULL, *ifname = NULL;
 	FILE *out, *in;
+	size_t klen;
 
 	progname = basename(argv[0]);
 
@@ -197,64 +436,28 @@ int main(int argc, char *argv[])
 		goto err;
 	}
 
-	buflen = board->imagelen;
-	kspace = buflen - HDR_LENGTH;
-
 	/* Get kernel length */
 	fseek(in, 0, SEEK_END);
 	klen = ftell(in);
 	rewind(in);
 
-	if (klen > kspace) {
-		ERR("file \"%s\" is too big - max size: 0x%08lX\n",
-		    ifname, kspace);
-		goto err_close_in;
-	}
-
-	/* If requested, resize buffer to remove padding */
-	if (strip_padding)
-		buflen = klen + HDR_LENGTH;
-
-	/* Allocate and initialize buffer for final image */
-	buf = malloc(buflen);
-	if (buf == NULL) {
-		ERRS("no memory for buffer: %s\n");
-		goto err_close_in;
-	}
-	memset(buf, PADDING_BYTE, buflen);
-
-	/* Load kernel */
-	kernel = buf + HDR_LENGTH;
-	fread(kernel, klen, 1, in);
-
-	/* Write magic values and filler */
-	writel(buf, HDR_OFF_MAGIC1, board->magic);
-	writel(buf, HDR_OFF_MAGIC2, board->magic);
-	writel(buf, HDR_OFF_FILLER, 0);
-
-	/* Write header and image length */
-	writel(buf, HDR_OFF_HDRLEN, HDR_LENGTH);
-	writel(buf, HDR_OFF_IMAGELEN, klen);
-
-	/* Write checksum and static hash */
-	sha1_csum(kernel, klen, buf + HDR_OFF_CHECKSUM);
-	memcpy(buf + HDR_OFF_STATICHASH, board->statichash, 20);
-
-	/* Save finished image */
 	out = fopen(ofname, "w");
 	if (out == NULL) {
 		ERRS("could not open \"%s\" for writing: %s", ofname);
-		goto err_free;
+		goto err_close_in;
 	}
-	fwrite(buf, buflen, 1, out);
 
-	ret = EXIT_SUCCESS;
+	switch (board->header_type) {
+	case MERAKI_NEW:
+		ret = meraki_new(board, klen, out, in);
+		break;
+	case MERAKI_OLD:
+		ret = meraki_old(board, klen, out, in);
+		break;
+	}
 
 	fclose(out);
 
-err_free:
-	free(buf);
-
 err_close_in:
 	fclose(in);
 
-- 
2.7.0
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