// SPDX-License-Identifier: GPL-2.0-only /* * zytrx - add header to images for ZyXEL NR7101 * * Based on add_header.c - partially based on OpenWrt's * motorola-bin.c * * Copyright (C) 2008 Imre Kaloz * Gabor Juhos * Copyright (C) 2021 Bjørn Mork * 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 #include #include #include #include #include #include #include #include #include #include #define BPB 8 /* bits/byte */ static uint32_t crc32[1<> 1)) : (crc >> 1); crc32[n] = crc; } } static uint32_t crc32buf(const unsigned char *buf, size_t len) { uint32_t crc = 0xFFFFFFFF; for (; len; len--, buf++) crc = crc32[(uint8_t)crc ^ *buf] ^ (crc >> BPB); return ~crc; } /* HDR0 reversed, to be stored as BE */ #define MAGIC 0x30524448 /* HDR0 reversed, to be stored as BE */ /* All numbers are stored as BE */ struct zytrx_t { uint32_t magic; uint32_t len_h; /* Length of this header */ uint32_t len_t; /* Total length of file */ uint32_t crc32_p; /* Bit inverted 32-bit CRC of image payload */ uint8_t verInt[32]; /* String "5.0.0.0\n" zero padded */ uint8_t verExt[32]; /* String "\n" zero padded */ uint32_t len_p; /* Length of image payload */ uint8_t pad1[12]; /* zero padding(?) */ uint8_t code[164]; /* string "3 6035 122 0\n" zero padded */ uint8_t chipid[8]; /* string "MT7621A" zero padded */ uint8_t boardid[16]; /* string "NR7101" zero padded */ uint32_t modelid; /* modelid as 4 BCD digits: 0x07010001 */ uint8_t pad2[8]; /* zero padding(?) */ uint8_t swVersionInt[32]; /* ZyXEL version string: "1.00(ABUV.0)D0" zero padded */ uint8_t swVersionExt[32]; /* identical to swVersionInt */ uint8_t pad4[4]; /* zero padding(?) */ uint32_t kernelChksum; /* no idea how this is computed - reported but not validated */ uint8_t pad5[4]; /* zero padding(?) */ uint32_t crc32_h; /* Bit inverted 32-bit CRC of this header payload */ uint8_t pad6[4]; /* zero padding(?) */ }; /* static?() field values of unknown meaning - maybe ove to board * table when we know the significance */ #define VER_INT "5.0.0.0\n" #define VER_EXT "\n" #define CODE "3 6035 122 0\n" #define KERNELCHKSUM 0x12345678 /* table of supported devices using this header format */ static struct board_t { uint8_t chipid[8]; uint8_t boardid[16]; uint32_t modelid; } boards[] = { { "MT7621A", "NR7101", 0x07010001 }, {} }; static int find_board(struct zytrx_t *h, char *board) { struct board_t *p; for (p = boards; p->modelid; p++) { if (strncmp((const char *)p->boardid, board, sizeof(p->boardid))) continue; memcpy(h->chipid, p->chipid, sizeof(h->chipid)); memcpy(h->boardid, p->boardid, sizeof(h->boardid)); h->modelid = htonl(p->modelid); return 0; } return -1; } static void usage(const char *name) { struct board_t *p; fprintf(stderr, "Usage:\n"); fprintf(stderr, " %s -B -v -i [-o ]\n\n", name); fprintf(stderr, "Supported values:\n"); for (p = boards; p->modelid; p++) fprintf(stderr, "\t%-12s\n", p->boardid); fprintf(stderr, "\nExample:\n"); fprintf(stderr, " %s -B %s -v foobar-1.0 -i my.img -o out.img\n\n", name, boards[0].boardid); exit(EXIT_FAILURE); } static void errexit(const char *msg) { fprintf(stderr, "ERR: %s: %s\n", msg, errno ? strerror(errno) : "unknown"); exit(EXIT_FAILURE); } static void *map_input(const char *name, size_t *len) { struct stat stat; void *mapped; int fd; fd = open(name, O_RDONLY); if (fd < 0) return NULL; if (fstat(fd, &stat) < 0) { close(fd); return NULL; } *len = stat.st_size; mapped = mmap(NULL, stat.st_size, PROT_READ, MAP_SHARED, fd, 0); if (close(fd) < 0) { (void) munmap(mapped, stat.st_size); return NULL; } return mapped; } int main(int argc, char **argv) { int c, fdout = STDOUT_FILENO; void *input_file = NULL; size_t file_len, len; uint32_t crc; struct zytrx_t h = { .magic = htonl(MAGIC), .len_h = htonl(sizeof(h)), .verInt = VER_INT, .verExt = VER_EXT, .code = CODE, .kernelChksum = htonl(KERNELCHKSUM), }; while ((c = getopt(argc, argv, "B:v:i:o:")) != -1) { switch (c) { case 'B': if (find_board(&h, optarg) < 0) errexit("unsupported board"); break; case 'v': len = strlen(optarg); if (len > sizeof(h.swVersionInt)) errexit("version string too long"); memcpy(h.swVersionInt, optarg, len); memcpy(h.swVersionExt, optarg, len); break; case 'i': input_file = map_input(optarg, &file_len); if (!input_file) errexit(optarg); break; case 'o': fdout = open(optarg, O_WRONLY | O_CREAT, 0644); if (fdout < 0) errexit(optarg); break; default: usage(argv[0]); } } /* required paremeters */ if (!input_file || !h.modelid || !h.swVersionInt[0]) usage(argv[0]); /* length fields */ h.len_t = htonl(sizeof(h) + file_len); h.len_p = htonl(file_len); /* crc fields */ init_crc32(); crc = crc32buf(input_file, file_len); h.crc32_p = htonl(~crc); crc = crc32buf((unsigned char *)&h, sizeof(h)); h.crc32_h = htonl(~crc); /* dump new image */ write(fdout, &h, sizeof(h)); write(fdout, input_file, file_len); /* close files */ munmap(input_file, file_len); if (fdout != STDOUT_FILENO) close(fdout); return EXIT_SUCCESS; }