firmware-utils: bcm4908img: tool adding BCM4908 image tail

Flashing image with BCM4908 CFE bootloader requires specific firmware
format. It needs 20 extra bytes with magic numbers and CRC32 appended.

This tools allows appending such a tail to the specified image and also
verifying CRC32 of existing BCM4908 image.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

2 files changed, 380 insertions, 0 deletions

diff --git a/tools/firmware-utils/Makefile b/tools/firmware-utils/Makefile
index a8c6ab4f65..055082593b 100644
--- a/tools/firmware-utils/Makefile
+++ b/tools/firmware-utils/Makefile
@@ -27,6 +27,7 @@ define Host/Compile
 	$(call cc,add_header)
 	$(call cc,addpattern)
 	$(call cc,asustrx)
+	$(call cc,bcm4908img,-Wall)
 	$(call cc,bcm4908kernel,-Wall)
 	$(call cc,buffalo-enc buffalo-lib,-Wall)
 	$(call cc,buffalo-tag buffalo-lib,-Wall)
diff --git a/tools/firmware-utils/src/bcm4908img.c b/tools/firmware-utils/src/bcm4908img.c
new file mode 100644
index 0000000000..86a187b146
--- /dev/null
+++ b/tools/firmware-utils/src/bcm4908img.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>
+ */
+
+#include <byteswap.h>
+#include <endian.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#if !defined(__BYTE_ORDER)
+#error "Unknown byte order"
+#endif
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define cpu_to_le32(x)	bswap_32(x)
+#define le32_to_cpu(x)	bswap_32(x)
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
+#define cpu_to_le32(x)	(x)
+#define le32_to_cpu(x)	(x)
+#else
+#error "Unsupported endianness"
+#endif
+
+struct bcm4908img_tail {
+	uint32_t crc32;
+	uint32_t unk1;
+	uint32_t family;
+	uint32_t unk2;
+	uint32_t unk3;
+};
+
+char *pathname;
+static size_t prefix_len;
+static size_t suffix_len;
+
+static inline size_t bcm4908img_min(size_t x, size_t y) {
+	return x < y ? x : y;
+}
+
+/**************************************************
+ * CRC32
+ **************************************************/
+
+static const uint32_t crc32_tbl[] = {
+	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,
+};
+
+uint32_t bcm4908img_crc32(uint32_t crc, uint8_t *buf, size_t len) {
+	while (len) {
+		crc = crc32_tbl[(crc ^ *buf) & 0xff] ^ (crc >> 8);
+		buf++;
+		len--;
+	}
+
+	return crc;
+}
+
+/**************************************************
+ * Check
+ **************************************************/
+
+static void bcm4908img_check_parse_options(int argc, char **argv) {
+	int c;
+
+	while ((c = getopt(argc, argv, "p:s:")) != -1) {
+		switch (c) {
+		case 'p':
+			prefix_len = atoi(optarg);
+			break;
+		case 's':
+			suffix_len = atoi(optarg);
+			break;
+		}
+	}
+}
+
+static int bcm4908img_check(int argc, char **argv) {
+	struct bcm4908img_tail tail;
+	struct stat st;
+	uint8_t buf[1024];
+	uint32_t crc32;
+	size_t length;
+	size_t bytes;
+	FILE *fp;
+	int err = 0;
+
+	if (argc < 3) {
+		fprintf(stderr, "No BCM4908 image pathname passed\n");
+		err = -EINVAL;
+		goto out;
+	}
+	pathname = argv[2];
+
+	optind = 3;
+	bcm4908img_check_parse_options(argc, argv);
+
+	if (stat(pathname, &st)) {
+		fprintf(stderr, "Failed to stat %s\n", pathname);
+		err = -EIO;
+		goto out;
+	}
+
+	fp = fopen(pathname, "r");
+	if (!fp) {
+		fprintf(stderr, "Failed to open %s\n", pathname);
+		err = -EACCES;
+		goto out;
+	}
+
+	fseek(fp, prefix_len, SEEK_SET);
+
+	crc32 = 0xffffffff;
+	length = st.st_size - prefix_len - sizeof(tail) - suffix_len;
+	while (length && (bytes = fread(buf, 1, bcm4908img_min(sizeof(buf), length), fp)) > 0) {
+		crc32 = bcm4908img_crc32(crc32, buf, bytes);
+		length -= bytes;
+	}
+
+	if (length) {
+		fprintf(stderr, "Failed to read last %zd B of data from %s\n", length, pathname);
+		err = -EIO;
+		goto err_close;
+	}
+
+	if (fread(&tail, 1, sizeof(tail), fp) != sizeof(tail)) {
+		fprintf(stderr, "Failed to read BCM4908 image tail\n");
+		err = -EIO;
+		goto err_close;
+	}
+
+	if (crc32 != le32_to_cpu(tail.crc32)) {
+		fprintf(stderr, "Invalid data crc32: 0x%08x instead of 0x%08x\n", crc32, le32_to_cpu(tail.crc32));
+		err =  -EPROTO;
+		goto err_close;
+	}
+
+	printf("Found a valid BCM4908 image (crc: 0x%08x)\n", crc32);
+
+err_close:
+	fclose(fp);
+out:
+	return err;
+}
+
+/**************************************************
+ * Create
+ **************************************************/
+
+static ssize_t bcm4908img_create_append_file(FILE *trx, const char *in_path, uint32_t *crc32) {
+	FILE *in;
+	size_t bytes;
+	ssize_t length = 0;
+	uint8_t buf[1024];
+
+	in = fopen(in_path, "r");
+	if (!in) {
+		fprintf(stderr, "Failed to open %s\n", in_path);
+		return -EACCES;
+	}
+
+	while ((bytes = fread(buf, 1, sizeof(buf), in)) > 0) {
+		if (fwrite(buf, 1, bytes, trx) != bytes) {
+			fprintf(stderr, "Failed to write %zu B to %s\n", bytes, pathname);
+			length = -EIO;
+			break;
+		}
+		*crc32 = bcm4908img_crc32(*crc32, buf, bytes);
+		length += bytes;
+	}
+
+	fclose(in);
+
+	return length;
+}
+
+static ssize_t bcm4908img_create_append_zeros(FILE *trx, size_t length) {
+	uint8_t *buf;
+
+	buf = malloc(length);
+	if (!buf)
+		return -ENOMEM;
+	memset(buf, 0, length);
+
+	if (fwrite(buf, 1, length, trx) != length) {
+		fprintf(stderr, "Failed to write %zu B to %s\n", length, pathname);
+		free(buf);
+		return -EIO;
+	}
+
+	free(buf);
+
+	return length;
+}
+
+static ssize_t bcm4908img_create_align(FILE *trx, size_t cur_offset, size_t alignment) {
+	if (cur_offset & (alignment - 1)) {
+		size_t length = alignment - (cur_offset % alignment);
+		return bcm4908img_create_append_zeros(trx, length);
+	}
+
+	return 0;
+}
+
+static int bcm4908img_create(int argc, char **argv) {
+	struct bcm4908img_tail tail = {
+		.unk1 = cpu_to_le32(0x5732),
+		.family = cpu_to_le32(0x4908),
+		.unk2 = cpu_to_le32(0x03),
+		.unk3 = cpu_to_le32(0x02),
+	};
+	uint32_t crc32 = 0xffffffff;
+	size_t cur_offset = 0;
+	ssize_t bytes;
+	FILE *fp;
+	int c;
+	int err = 0;
+
+	if (argc < 3) {
+		fprintf(stderr, "No BCM4908 image pathname passed\n");
+		err = -EINVAL;
+		goto out;
+	}
+	pathname = argv[2];
+
+	fp = fopen(pathname, "w+");
+	if (!fp) {
+		fprintf(stderr, "Failed to open %s\n", pathname);
+		err = -EACCES;
+		goto out;
+	}
+
+	optind = 3;
+	while ((c = getopt(argc, argv, "f:a:A:")) != -1) {
+		switch (c) {
+		case 'f':
+			bytes = bcm4908img_create_append_file(fp, optarg, &crc32);
+			if (bytes < 0) {
+				fprintf(stderr, "Failed to append file %s\n", optarg);
+			} else {
+				cur_offset += bytes;
+			}
+			break;
+		case 'a':
+			bytes = bcm4908img_create_align(fp, cur_offset, strtol(optarg, NULL, 0));
+			if (bytes < 0)
+				fprintf(stderr, "Failed to append zeros\n");
+			else
+				cur_offset += bytes;
+			break;
+		case 'A':
+			bytes = strtol(optarg, NULL, 0) - cur_offset;
+			if (bytes < 0) {
+				fprintf(stderr, "Current BCM4908 image length is 0x%zx, can't pad it with zeros to 0x%lx\n", cur_offset, strtol(optarg, NULL, 0));
+			} else {
+				bytes = bcm4908img_create_append_zeros(fp, bytes);
+				if (bytes < 0)
+					fprintf(stderr, "Failed to append zeros\n");
+				else
+					cur_offset += bytes;
+			}
+			break;
+		}
+		if (err)
+			goto err_close;
+	}
+
+	tail.crc32 = cpu_to_le32(crc32);
+
+	bytes = fwrite(&tail, 1, sizeof(tail), fp);
+	if (bytes != sizeof(tail)) {
+		fprintf(stderr, "Failed to write BCM4908 image tail to %s\n", pathname);
+		return -EIO;
+	}
+
+err_close:
+	fclose(fp);
+out:
+	return err;
+}
+
+/**************************************************
+ * Start
+ **************************************************/
+
+static void usage() {
+	printf("Usage:\n");
+	printf("\n");
+	printf("Checking a BCM4908 image:\n");
+	printf("\tbcm4908img check <file> [options]\tcheck if images is valid\n");
+	printf("\t-p prefix\t\t\tlength of custom header to skip (default: 0)\n");
+	printf("\t-s suffix\t\t\tlength of custom tail to skip (default: 0)\n");
+	printf("\n");
+	printf("Creating a new BCM4908 image:\n");
+	printf("\tbcm4908img create <file> [options]\n");
+	printf("\t-f file\t\t\t\tadd data from specified file\n");
+	printf("\t-a alignment\t\t\tpad image with zeros to specified alignment\n");
+	printf("\t-A offset\t\t\t\tappend zeros until reaching specified offset\n");
+}
+
+int main(int argc, char **argv) {
+	if (argc > 1) {
+		if (!strcmp(argv[1], "check"))
+			return bcm4908img_check(argc, argv);
+		else if (!strcmp(argv[1], "create"))
+			return bcm4908img_create(argc, argv);
+	}
+
+	usage();
+	return 0;
+}