tools/firmware-utils: enhance mktplinkfw utility

Attached patch enhances the mktplinkfw utility:
1. existing firmware files in TP-Link format can now be inspected, showing eg. the used offsets
2. optionally the kernel and rootfs parts can be extracted (saves calculations for dd)
3. when generating firmwares, kernel entry point, load address and rootfs offset can be overwritten (for experienced users)

Patch-by: Pieter "Fate" Hollants <pieter@hollants.com>

SVN-Revision: 22169

tools/firmware-utils/src/mktplinkfw.c

@@ -93,11 +93,17 @@ static char *version = "ver. 1.0";
 static char *board_id;
 static struct board_info *board;
 static struct file_info kernel_info;
+static uint32_t kernel_la = 0;
+static uint32_t kernel_ep = 0;
 static struct file_info rootfs_info;
+static uint32_t rootfs_ofs = 0;
 static struct file_info boot_info;
 static int combined;
 static int strip_padding;
 
+static struct file_info inspect_info;
+static int extract = 0;
+
 char md5salt_normal[MD5SUM_LEN] = {
 	0xdc, 0xd7, 0x3a, 0xa5, 0xc3, 0x95, 0x98, 0xfb,
 	0xdd, 0xf9, 0xe7, 0xf4, 0x0e, 0xae, 0x47, 0x38,
@@ -214,6 +220,19 @@ static struct board_info *find_board(char *id)
 	return ret;
 }
 
+static struct board_info *find_board_by_hwid(uint32_t hw_id)
+{
+	struct board_info *board;
+
+	for (board = boards; board->id != NULL; board++) {
+		if (hw_id == board->hw_id)
+			return board;
+	};
+
+	return NULL;
+}
+
+
 static void usage(int status)
 {
 	FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
@@ -225,12 +244,17 @@ static void usage(int status)
 "Options:\n"
 "  -B <board>      create image for the board specified with <board>\n"
 "  -c              use combined kernel image\n"
+"  -E <ep>         overwrite kernel entry point with <ep> (hexval prefixed with 0x)\n"
+"  -L <la>         overwrite kernel load address with <la> (hexval prefixed with 0x)\n"
 "  -k <file>       read kernel image from the file <file>\n"
 "  -r <file>       read rootfs image from the file <file>\n"
+"  -R <offset>     overwrite rootfs offset with <offset> (hexval prefixed with 0x)\n"
 "  -o <file>       write output to the file <file>\n"
 "  -s              strip padding from the end of the image\n"
 "  -N <vendor>     set image vendor to <vendor>\n"
 "  -V <version>    set image version to <version>\n"
+"  -i <file>       inspect given firmware file <file>\n"
+"  -x              extract kernel and rootfs while inspecting (requires -i)\n"
 "  -h              show this screen\n"
 	);
 
@@ -294,6 +318,17 @@ static int check_options(void)
 {
 	int ret;
 
+	if (inspect_info.file_name) {
+		ret = get_file_stat(&inspect_info);
+		if (ret)
+			return ret;
+
+		return 0;
+	} else if (extract) {
+		ERR("no firmware for inspection specified");
+		return -1;
+	}
+
 	if (board_id == NULL) {
 		ERR("no board specified");
 		return -1;
@@ -304,6 +339,12 @@ static int check_options(void)
 		ERR("unknown/unsupported board id \"%s\"", board_id);
 		return -1;
 	}
+	if (!kernel_la)
+		kernel_la = board->kernel_la;
+	if (!kernel_ep)
+		kernel_ep = board->kernel_ep;
+	if (!rootfs_ofs)
+		rootfs_ofs = board->rootfs_ofs;
 
 	if (kernel_info.file_name == NULL) {
 		ERR("no kernel image specified");
@@ -322,7 +363,7 @@ static int check_options(void)
 		}
 	} else {
 		if (kernel_info.file_size >
-		    board->rootfs_ofs - sizeof(struct fw_header)) {
+		    rootfs_ofs - sizeof(struct fw_header)) {
 			ERR("kernel image is too big");
 			return -1;
 		}
@@ -336,7 +377,7 @@ static int check_options(void)
 			return ret;
 
 		if (rootfs_info.file_size >
-                    (board->fw_max_len - board->rootfs_ofs)) {
+                    (board->fw_max_len - rootfs_ofs)) {
 			ERR("rootfs image is too big");
 			return -1;
 		}
@@ -367,13 +408,13 @@ static void fill_header(char *buf, int len)
 	else
 		memcpy(hdr->md5sum1, md5salt_boot, sizeof(hdr->md5sum1));
 
-	hdr->kernel_la = HOST_TO_BE32(board->kernel_la);
+	hdr->kernel_la = HOST_TO_BE32(kernel_la);
-	hdr->kernel_ep = HOST_TO_BE32(board->kernel_ep);
+	hdr->kernel_ep = HOST_TO_BE32(kernel_ep);
 	hdr->fw_length = HOST_TO_BE32(board->fw_max_len);
 	hdr->kernel_ofs = HOST_TO_BE32(sizeof(struct fw_header));
 	hdr->kernel_len = HOST_TO_BE32(kernel_info.file_size);
 	if (!combined) {
-		hdr->rootfs_ofs = HOST_TO_BE32(board->rootfs_ofs);
+		hdr->rootfs_ofs = HOST_TO_BE32(rootfs_ofs);
 		hdr->rootfs_len = HOST_TO_BE32(rootfs_info.file_size);
 	}
 
@@ -437,12 +478,12 @@ static int build_fw(void)
 	writelen = kernel_info.file_size;
 
 	if (!combined) {
-		p = buf + board->rootfs_ofs;
+		p = buf + rootfs_ofs;
 		ret = read_to_buf(&rootfs_info, p);
 		if (ret)
 			goto out_free_buf;
 
-		writelen = board->rootfs_ofs + rootfs_info.file_size;
+		writelen = rootfs_ofs + rootfs_info.file_size;
 	}
 
 	if (!strip_padding)
@@ -461,6 +502,216 @@ static int build_fw(void)
 	return ret;
 }
 
+/* Helper functions to inspect_fw() representing different output formats */
+static inline void inspect_fw_pstr(char *label, char *str)
+{
+	printf("%-23s: %s\n", label, str);
+}
+
+static inline void inspect_fw_phex(char *label, uint32_t val)
+{
+	printf("%-23s: 0x%08x\n", label, val);
+}
+
+static inline void inspect_fw_phexpost(char *label,
+                                       uint32_t val, char *post)
+{
+	printf("%-23s: 0x%08x (%s)\n", label, val, post);
+}
+
+static inline void inspect_fw_phexdef(char *label,
+                                      uint32_t val, uint32_t defval)
+{
+	printf("%-23s: 0x%08x                  ", label, val);
+
+	if (val == defval)
+		printf("(== OpenWrt default)\n");
+	else
+		printf("(OpenWrt default: 0x%08x)\n", defval);
+}
+
+static inline void inspect_fw_phexexp(char *label,
+                                      uint32_t val, uint32_t expval)
+{
+	printf("%-23s: 0x%08x ", label, val);
+
+	if (val == expval)
+		printf("(ok)\n");
+	else
+		printf("(expected: 0x%08x)\n", expval);
+}
+
+static inline void inspect_fw_phexdec(char *label, uint32_t val)
+{
+	printf("%-23s: 0x%08x / %8u bytes\n", label, val, val);
+}
+
+static inline void inspect_fw_phexdecdef(char *label,
+                                         uint32_t val, uint32_t defval)
+{
+	printf("%-23s: 0x%08x / %8u bytes ", label, val, val);
+
+	if (val == defval)
+		printf("(== OpenWrt default)\n");
+	else
+		printf("(OpenWrt default: 0x%08x)\n", defval);
+}
+
+static inline void inspect_fw_pmd5sum(char *label, uint8_t *val, char *text)
+{
+	int i;
+
+	printf("%-23s:", label);
+	for (i=0; i<MD5SUM_LEN; i++)
+		printf(" %02x", val[i]);
+	printf(" %s\n", text);
+}
+
+static int inspect_fw(void)
+{
+	char *buf;
+	struct fw_header *hdr;
+	uint8_t md5sum[MD5SUM_LEN];
+	struct board_info *board;
+	int ret = EXIT_FAILURE;
+
+	buf = malloc(inspect_info.file_size);
+	if (!buf) {
+		ERR("no memory for buffer!\n");
+		goto out;
+	}
+
+	ret = read_to_buf(&inspect_info, buf);
+	if (ret)
+		goto out_free_buf;
+	hdr = (struct fw_header *)buf;
+
+	inspect_fw_pstr("File name", inspect_info.file_name);
+	inspect_fw_phexdec("File size", inspect_info.file_size);
+
+	if (BE32_TO_HOST(hdr->version) != HEADER_VERSION_V1) {
+		ERR("file does not seem to have V1 header!\n");
+		goto out_free_buf;
+	}
+
+	inspect_fw_phexdec("Version 1 Header size", sizeof(struct fw_header));
+
+	if (BE32_TO_HOST(hdr->unk1) != 0)
+		inspect_fw_phexdec("Unknown value 1", hdr->unk1);
+
+	memcpy(md5sum, hdr->md5sum1, sizeof(md5sum));
+	if (BE32_TO_HOST(hdr->boot_len) == 0)
+		memcpy(hdr->md5sum1, md5salt_normal, sizeof(md5sum));
+	else
+		memcpy(hdr->md5sum1, md5salt_boot, sizeof(md5sum));
+	get_md5(buf, inspect_info.file_size, hdr->md5sum1);
+
+	if (memcmp(md5sum, hdr->md5sum1, sizeof(md5sum))) {
+		inspect_fw_pmd5sum("Header MD5Sum1", md5sum, "(*ERROR*)");
+		inspect_fw_pmd5sum("          --> expected", hdr->md5sum1, "");
+	} else {
+		inspect_fw_pmd5sum("Header MD5Sum1", md5sum, "(ok)");
+	}
+	if (BE32_TO_HOST(hdr->unk2) != 0)
+		inspect_fw_phexdec("Unknown value 2", hdr->unk2);
+	inspect_fw_pmd5sum("Header MD5Sum2", hdr->md5sum2,
+	                   "(purpose yet unknown, unchecked here)");
+	if (BE32_TO_HOST(hdr->unk3) != 0)
+		inspect_fw_phexdec("Unknown value 3", hdr->unk3);
+
+	printf("\n");
+
+	inspect_fw_pstr("Vendor name", hdr->vendor_name);
+	inspect_fw_pstr("Firmware version", hdr->fw_version);
+	board = find_board_by_hwid(BE32_TO_HOST(hdr->hw_id));
+	if (board) {
+		inspect_fw_phexpost("Hardware ID",
+		                    BE32_TO_HOST(hdr->hw_id), board->id);
+		inspect_fw_phexexp("Hardware Revision",
+		                   BE32_TO_HOST(hdr->hw_rev), board->hw_rev);
+	} else {
+		inspect_fw_phexpost("Hardware ID",
+		                    BE32_TO_HOST(hdr->hw_id), "unknown");
+		inspect_fw_phex("Hardware Revision",
+		                BE32_TO_HOST(hdr->hw_rev));
+	}
+
+	printf("\n");
+
+	inspect_fw_phexdec("Kernel data offset",
+	                   BE32_TO_HOST(hdr->kernel_ofs));
+	inspect_fw_phexdec("Kernel data length",
+	                   BE32_TO_HOST(hdr->kernel_len));
+	if (board) {
+		inspect_fw_phexdef("Kernel load address",
+		                   BE32_TO_HOST(hdr->kernel_la),
+		                   board->kernel_la);
+		inspect_fw_phexdef("Kernel entry point",
+		                   BE32_TO_HOST(hdr->kernel_ep),
+		                   board->kernel_ep);
+		inspect_fw_phexdecdef("Rootfs data offset",
+		                      BE32_TO_HOST(hdr->rootfs_ofs),
+		                      board->rootfs_ofs);
+	} else {
+		inspect_fw_phex("Kernel load address",
+		                BE32_TO_HOST(hdr->kernel_la));
+		inspect_fw_phex("Kernel entry point",
+		                BE32_TO_HOST(hdr->kernel_ep));
+		inspect_fw_phexdec("Rootfs data offset",
+		                   BE32_TO_HOST(hdr->rootfs_ofs));
+	}
+	inspect_fw_phexdec("Rootfs data length",
+	                   BE32_TO_HOST(hdr->rootfs_len));
+	inspect_fw_phexdec("Boot loader data offset",
+	                   BE32_TO_HOST(hdr->boot_ofs));
+	inspect_fw_phexdec("Boot loader data length",
+	                   BE32_TO_HOST(hdr->boot_len));
+	inspect_fw_phexdec("Total firmware length",
+	                   BE32_TO_HOST(hdr->fw_length));
+
+	if (extract) {
+		FILE *fp;
+		char *filename;
+
+		printf("\n");
+
+		filename = malloc(strlen(inspect_info.file_name) + 8);
+		sprintf(filename, "%s-kernel", inspect_info.file_name);
+		printf("Extracting kernel to \"%s\"...\n", filename);
+		fp = fopen(filename, "w");
+		if (fp)	{
+			if (!fwrite(buf + BE32_TO_HOST(hdr->kernel_ofs),
+			            BE32_TO_HOST(hdr->kernel_len), 1, fp)) {
+				ERR("error in fwrite(): %s", strerror(errno));
+			}
+			fclose(fp);
+		} else {
+			ERR("error in fopen(): %s", strerror(errno));
+		}
+		free(filename);
+
+		filename = malloc(strlen(inspect_info.file_name) + 8);
+		sprintf(filename, "%s-rootfs", inspect_info.file_name);
+		printf("Extracting rootfs to \"%s\"...\n", filename);
+		fp = fopen(filename, "w");
+		if (fp)	{
+			if (!fwrite(buf + BE32_TO_HOST(hdr->rootfs_ofs),
+			            BE32_TO_HOST(hdr->rootfs_len), 1, fp)) {
+				ERR("error in fwrite(): %s", strerror(errno));
+			}
+			fclose(fp);
+		} else {
+			ERR("error in fopen(): %s", strerror(errno));
+		}
+		free(filename);
+	}
+
+ out_free_buf:
+	free(buf);
+ out:
+	return ret;
+}
+
 int main(int argc, char *argv[])
 {
 	int ret = EXIT_FAILURE;
@@ -473,7 +724,7 @@ int main(int argc, char *argv[])
 	while ( 1 ) {
 		int c;
 
-		c = getopt(argc, argv, "B:V:N:ck:r:o:hs");
+		c = getopt(argc, argv, "B:E:L:V:N:ci:k:r:R:o:xhs");
 		if (c == -1)
 			break;
 
@@ -481,6 +732,12 @@ int main(int argc, char *argv[])
 		case 'B':
 			board_id = optarg;
 			break;
+		case 'E':
+			sscanf(optarg, "0x%x", &kernel_ep);
+			break;
+		case 'L':
+			sscanf(optarg, "0x%x", &kernel_la);
+			break;
 		case 'V':
 			version = optarg;
 			break;
@@ -496,12 +753,21 @@ int main(int argc, char *argv[])
 		case 'r':
 			rootfs_info.file_name = optarg;
 			break;
+		case 'R':
+			sscanf(optarg, "0x%x", &rootfs_ofs);
+			break;
 		case 'o':
 			ofname = optarg;
 			break;
 		case 's':
 			strip_padding = 1;
 			break;
+		case 'i':
+			inspect_info.file_name = optarg;
+			break;
+		case 'x':
+			extract = 1;
+			break;
 		case 'h':
 			usage(EXIT_SUCCESS);
 			break;
@@ -515,7 +781,10 @@ int main(int argc, char *argv[])
 	if (ret)
 		goto out;
 
-	ret = build_fw();
+	if (!inspect_info.file_name)
+		ret = build_fw();
+	else
+		ret = inspect_fw();
 
  out:
 	return ret;