--- /dev/null
+/*
+ * --- ZyXEL header format ---
+ * Original Version by Benjamin Berg <benjamin@sipsolutions.net>
+ * C implementation based on generation-script by Christian Lamparter <chunkeey@gmail.com>
+ *
+ * The firmware image prefixed with a header (which is written into the MTD device).
+ * The header is one erase block (~64KiB) in size, but the checksum only convers the
+ * first 2KiB. Padding is 0xff. All integers are in big-endian.
+ *
+ * The checksum is always a 16-Bit System V checksum (sum -s) stored in a 32-Bit integer.
+ *
+ * 4 bytes: checksum of the rootfs image
+ * 4 bytes: length of the contained rootfs image file (big endian)
+ * 32 bytes: Firmware Version string (NUL terminated, 0xff padded)
+ * 4 bytes: checksum over the header partition (big endian - see below)
+ * 64 bytes: Model (e.g. "NBG6617", NUL termiated, 0xff padded)
+ * 4 bytes: checksum of the kernel partition
+ * 4 bytes: length of the contained kernel image file (big endian)
+ * rest: 0xff padding (To erase block size)
+ *
+ * The kernel partition checksum and length is not used for every device.
+ * If it's notused, pad those 8 bytes with 0xFF.
+ *
+ * The checksums are calculated by adding up all bytes and if a 16bit
+ * overflow occurs, one is added and the sum is masked to 16 bit:
+ * csum = csum + databyte; if (csum > 0xffff) { csum += 1; csum &= 0xffff };
+ * Should the file have an odd number of bytes then the byte len-0x800 is
+ * used additionally.
+ *
+ * The checksum for the header is calculated over the first 2048 bytes with
+ * the rootfs image checksum as the placeholder during calculation.
+ *
+ * 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.
+ *
+ */
+#include <fcntl.h>
+#include <getopt.h>
+#include <libgen.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#include <arpa/inet.h>
+
+#define VERSION_STRING_LEN 31
+#define ROOTFS_HEADER_LEN 40
+
+#define KERNEL_HEADER_LEN 8
+
+#define BOARD_NAME_LEN 64
+#define BOARD_HEADER_LEN 68
+
+#define HEADER_PARTITION_CALC_LENGTH 2048
+#define HEADER_PARTITION_LENGTH 0x10000
+
+struct file_info {
+ char *name; /* name of the file */
+ char *data; /* file content */
+ size_t size; /* length of the file */
+};
+
+static char *progname;
+
+static char *board_name = 0;
+static char *version_name = 0;
+static unsigned int rootfs_size = 0;
+
+static struct file_info kernel = { NULL, NULL, 0 };
+static struct file_info rootfs = { NULL, NULL, 0 };
+static struct file_info rootfs_out = { NULL, NULL, 0 };
+static struct file_info out = { NULL, NULL, 0 };
+
+#define ERR(fmt, ...) do { \
+ fprintf(stderr, "[%s] *** error: " fmt "\n", \
+ progname, ## __VA_ARGS__ ); \
+} while (0)
+
+void map_file(struct file_info *finfo)
+{
+ struct stat file_stat = {0};
+ int fd;
+
+ fd = open(finfo->name, O_RDONLY, (mode_t)0600);
+ if (fd == -1) {
+ ERR("Error while opening file %s.", finfo->name);
+ exit(EXIT_FAILURE);
+ }
+
+ if (fstat(fd, &file_stat) == -1) {
+ ERR("Error getting file size for %s.", finfo->name);
+ exit(EXIT_FAILURE);
+ }
+
+ finfo->size = file_stat.st_size;
+ finfo->data = mmap(0, finfo->size, PROT_READ, MAP_SHARED, fd, 0);
+
+ if (finfo->data == MAP_FAILED) {
+ ERR("Error mapping file %s.", finfo->name);
+ exit(EXIT_FAILURE);
+ }
+
+ close(fd);
+}
+
+void unmap_file(struct file_info *finfo)
+{
+ if(munmap(finfo->data, finfo->size) == -1) {
+ ERR("Error unmapping file %s.", finfo->name);
+ exit(EXIT_FAILURE);
+ }
+}
+
+void write_file(struct file_info *finfo)
+{
+ FILE *fout = fopen(finfo->name, "w");
+
+ fwrite(finfo->data, finfo->size, 1, fout);
+
+ if (ferror(fout)) {
+ ERR("Wanted to write, but something went wrong.");
+ exit(EXIT_FAILURE);
+ }
+
+ fclose(fout);
+}
+
+void usage(int status)
+{
+ FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
+
+ fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
+ fprintf(stream,
+ "\n"
+ "Options:\n"
+ " -k <kernel> path for kernel image\n"
+ " -r <rootfs> path for rootfs image\n"
+ " -s <rfssize> size of output rootfs\n"
+ " -v <version> version string\n"
+ " -b <boardname> name of board to generate image for\n"
+ " -o <out_name> name of output image\n"
+ " -h show this screen\n"
+ );
+
+ exit(status);
+}
+
+static int sysv_chksm(const unsigned char *data, int size)
+{
+ int r;
+ int checksum;
+ unsigned int s = 0; /* The sum of all the input bytes, modulo (UINT_MAX + 1). */
+
+
+ for (int i = 0; i < size; i++) {
+ s += data[i];
+ }
+
+ r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
+ checksum = (r & 0xffff) + (r >> 16);
+
+ return checksum;
+}
+
+static int zyxel_chksm(const unsigned char *data, int size)
+{
+ return htonl(sysv_chksm(data, size));
+}
+
+char *generate_rootfs_header(struct file_info filesystem, char *version)
+{
+ size_t version_string_length;
+ unsigned int chksm, size;
+ char *rootfs_header;
+ size_t ptr = 0;
+
+ rootfs_header = malloc(ROOTFS_HEADER_LEN);
+ if (!rootfs_header) {
+ ERR("Couldn't allocate memory for rootfs header!");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Prepare padding for firmware-version string here */
+ memset(rootfs_header, 0xff, ROOTFS_HEADER_LEN);
+
+ chksm = zyxel_chksm((const unsigned char *)filesystem.data, filesystem.size);
+ size = htonl(filesystem.size);
+
+ /* 4 bytes: checksum of the rootfs image */
+ memcpy(rootfs_header + ptr, &chksm, 4);
+ ptr += 4;
+
+ /* 4 bytes: length of the contained rootfs image file (big endian) */
+ memcpy(rootfs_header + ptr, &size, 4);
+ ptr += 4;
+
+ /* 32 bytes: Firmware Version string (NUL terminated, 0xff padded) */
+ version_string_length = strlen(version) <= VERSION_STRING_LEN ? strlen(version) : VERSION_STRING_LEN;
+ memcpy(rootfs_header + ptr, version, version_string_length);
+ ptr += version_string_length;
+ /* Add null-terminator */
+ rootfs_header[ptr] = 0x0;
+
+ return rootfs_header;
+}
+
+char *generate_kernel_header(struct file_info kernel)
+{
+ unsigned int chksm, size;
+ char *kernel_header;
+ size_t ptr = 0;
+
+ kernel_header = malloc(KERNEL_HEADER_LEN);
+ if (!kernel_header) {
+ ERR("Couldn't allocate memory for kernel header!");
+ exit(EXIT_FAILURE);
+ }
+
+ chksm = zyxel_chksm((const unsigned char *)kernel.data, kernel.size);
+ size = htonl(kernel.size);
+
+ /* 4 bytes: checksum of the kernel image */
+ memcpy(kernel_header + ptr, &chksm, 4);
+ ptr += 4;
+
+ /* 4 bytes: length of the contained kernel image file (big endian) */
+ memcpy(kernel_header + ptr, &size, 4);
+
+ return kernel_header;
+}
+
+unsigned int generate_board_header_checksum(char *kernel_hdr, char *rootfs_hdr, char *boardname)
+{
+ char *board_hdr_tmp;
+ unsigned int sum;
+ size_t ptr = 0;
+
+ /*
+ * The checksum of the board header is calculated over the first 2048 bytes of
+ * the header partition with the rootfs checksum used as a placeholder for then
+ * board checksum we calculate in this step. The checksum gained from this step
+ * is then used for the final board header partition.
+ */
+
+ board_hdr_tmp = malloc(HEADER_PARTITION_CALC_LENGTH);
+ if (!board_hdr_tmp) {
+ ERR("Couldn't allocate memory for temporary board header!");
+ exit(EXIT_FAILURE);
+ }
+ memset(board_hdr_tmp, 0xff, HEADER_PARTITION_CALC_LENGTH);
+
+ /* 40 bytes: RootFS header */
+ memcpy(board_hdr_tmp, rootfs_hdr, ROOTFS_HEADER_LEN);
+ ptr += ROOTFS_HEADER_LEN;
+
+ /* 4 bytes: RootFS checksum (BE) as placeholder for board-header checksum */
+ memcpy(board_hdr_tmp + ptr, rootfs_hdr, 4);
+ ptr += 4;
+
+ /* 32 bytes: Model (e.g. "NBG6617", NUL termiated, 0xff padded) */
+ memcpy(board_hdr_tmp + ptr, boardname, strlen(boardname));
+ ptr += strlen(boardname);
+ /* Add null-terminator */
+ board_hdr_tmp[ptr] = 0x0;
+ ptr = ROOTFS_HEADER_LEN + 4 + BOARD_NAME_LEN;
+
+ /* 8 bytes: Kernel header */
+ if (kernel_hdr)
+ memcpy(board_hdr_tmp + ptr, kernel_hdr, 8);
+
+ /* Calculate the checksum over the first 2048 bytes */
+ sum = zyxel_chksm((const unsigned char *)board_hdr_tmp, HEADER_PARTITION_CALC_LENGTH);
+ free(board_hdr_tmp);
+ return sum;
+}
+
+char *generate_board_header(char *kernel_hdr, char *rootfs_hdr, char *boardname)
+{
+ unsigned int board_checksum;
+ char *board_hdr;
+
+ board_hdr = malloc(BOARD_HEADER_LEN);
+ if (!board_hdr) {
+ ERR("Couldn't allocate memory for board header!");
+ exit(EXIT_FAILURE);
+ }
+ memset(board_hdr, 0xff, BOARD_HEADER_LEN);
+
+ /* 4 bytes: checksum over the header partition (big endian) */
+ board_checksum = generate_board_header_checksum(kernel_hdr, rootfs_hdr, boardname);
+ memcpy(board_hdr, &board_checksum, 4);
+
+ /* 32 bytes: Model (e.g. "NBG6617", NUL termiated, 0xff padded) */
+ memcpy(board_hdr + 4, boardname, strlen(boardname));
+ board_hdr[4 + strlen(boardname)] = 0x0;
+
+ return board_hdr;
+}
+
+int build_image()
+{
+ char *rootfs_header = NULL;
+ char *kernel_header = NULL;
+ char *board_header = NULL;
+
+ size_t ptr;
+
+ /* Load files */
+ if (kernel.name)
+ map_file(&kernel);
+ map_file(&rootfs);
+
+ /*
+ * Allocate memory and copy input rootfs for temporary output rootfs.
+ * This is important as we have to generate the rootfs checksum over the
+ * entire rootfs partition. As we might have to pad the partition to allow
+ * for flashing via ZyXEL's Web-GUI, we prepare the rootfs partition for the
+ * output image here (and also use it for calculating the rootfs checksum).
+ *
+ * The roofs padding has to be done with 0x00.
+ */
+ rootfs_out.data = calloc(rootfs_out.size, sizeof(char));
+ memcpy(rootfs_out.data, rootfs.data, rootfs.size);
+
+ /* Prepare headers */
+ rootfs_header = generate_rootfs_header(rootfs_out, version_name);
+ if (kernel.name)
+ kernel_header = generate_kernel_header(kernel);
+ board_header = generate_board_header(kernel_header, rootfs_header, board_name);
+
+ /* Prepare output file */
+ out.size = HEADER_PARTITION_LENGTH + rootfs_out.size;
+ if (kernel.name)
+ out.size += kernel.size;
+ out.data = malloc(out.size);
+ memset(out.data, 0xFF, out.size);
+
+ /* Build output image */
+ memcpy(out.data, rootfs_header, ROOTFS_HEADER_LEN);
+ memcpy(out.data + ROOTFS_HEADER_LEN, board_header, BOARD_HEADER_LEN);
+ if (kernel.name)
+ memcpy(out.data + ROOTFS_HEADER_LEN + BOARD_HEADER_LEN, kernel_header, KERNEL_HEADER_LEN);
+ ptr = HEADER_PARTITION_LENGTH;
+ memcpy(out.data + ptr, rootfs_out.data, rootfs_out.size);
+ ptr += rootfs_out.size;
+ if (kernel.name)
+ memcpy(out.data + ptr, kernel.data, kernel.size);
+
+ /* Write back output image */
+ write_file(&out);
+
+ /* Free allocated memory */
+ if (kernel.name)
+ unmap_file(&kernel);
+ unmap_file(&rootfs);
+ free(out.data);
+ free(rootfs_out.data);
+
+ free(rootfs_header);
+ if (kernel.name)
+ free(kernel_header);
+ free(board_header);
+
+ return 0;
+}
+
+int check_options()
+{
+ if (!rootfs.name) {
+ ERR("No rootfs filename supplied");
+ return -2;
+ }
+
+ if (!out.name) {
+ ERR("No output filename supplied");
+ return -3;
+ }
+
+ if (!board_name) {
+ ERR("No board-name supplied");
+ return -4;
+ }
+
+ if (!version_name) {
+ ERR("No version supplied");
+ return -5;
+ }
+
+ if (rootfs_size <= 0) {
+ ERR("Invalid rootfs size supplied");
+ return -6;
+ }
+
+ if (strlen(board_name) > 31) {
+ ERR("Board name is to long");
+ return -7;
+ }
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ int ret;
+ progname = basename(argv[0]);
+ while (1) {
+ int c;
+
+ c = getopt(argc, argv, "b:k:o:r:s:v:h");
+ if (c == -1)
+ break;
+
+ switch (c) {
+ case 'b':
+ board_name = optarg;
+ break;
+ case 'h':
+ usage(EXIT_SUCCESS);
+ break;
+ case 'k':
+ kernel.name = optarg;
+ break;
+ case 'o':
+ out.name = optarg;
+ break;
+ case 'r':
+ rootfs.name = optarg;
+ break;
+ case 's':
+ sscanf(optarg, "%u", &rootfs_size);
+ break;
+ case 'v':
+ version_name = optarg;
+ break;
+ default:
+ usage(EXIT_FAILURE);
+ break;
+ }
+ }
+
+ ret = check_options();
+ if (ret)
+ usage(EXIT_FAILURE);
+
+ /* As ZyXEL Web-GUI only accept images with a rootfs equal or larger than the first firmware shipped
+ * for the device, we need to pad rootfs partition to this size. To perform further calculations, we
+ * decide the size of this part here. In case the rootfs we want to integrate in our image is larger,
+ * take it's size, otherwise the supplied size.
+ *
+ * Be careful! We rely on assertion of correct size to be performed beforehand. It is unknown if images
+ * with a to large rootfs are accepted or not.
+ */
+ rootfs_out.size = rootfs_size < rootfs.size ? rootfs.size : rootfs_size;
+ return build_image();
+}
projects / project / firmware-utils.git / commitdiff