1/* 2 * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org> 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 as published 6 * by the Free Software Foundation. 7 * 8 */ 9 10#include <errno.h> 11#include <fcntl.h> 12#include <libgen.h> 13#include <stdio.h> 14#include <stdint.h> 15#include <stdlib.h> 16#include <string.h> 17#include <unistd.h> 18#include <stdbool.h> 19#include <sys/types.h> 20#include <sys/stat.h> 21 22static char *progname; 23static unsigned int xtra_offset; 24static unsigned char eof_mark[4] = {0xde, 0xad, 0xc0, 0xde}; 25static unsigned char jffs2_pad_be[] = "\x19\x85\x20\x04\x04\x00\x00\x00\xc4\x94\xdb\xf4"; 26static unsigned char jffs2_pad_le[] = "\x85\x19\x04\x20\x00\x00\x00\x04\xa8\xfb\xa0\xb4"; 27static unsigned char *pad = eof_mark; 28static int pad_len = sizeof(eof_mark); 29static bool pad_to_stdout = false; 30 31#define ERR(fmt, ...) do { \ 32 fflush(0); \ 33 fprintf(stderr, "[%s] *** error: " fmt "\n", \ 34 progname, ## __VA_ARGS__ ); \ 35} while (0) 36 37#define ERRS(fmt, ...) do { \ 38 int save = errno; \ 39 fflush(0); \ 40 fprintf(stderr, "[%s] *** error: " fmt ", %s\n", \ 41 progname, ## __VA_ARGS__, strerror(save)); \ 42} while (0) 43 44#define BUF_SIZE (64 * 1024) 45#define ALIGN(_x,_y) (((_x) + ((_y) - 1)) & ~((_y) - 1)) 46 47static int pad_image(char *name, uint32_t pad_mask) 48{ 49 char *buf; 50 int fd; 51 int outfd; 52 ssize_t in_len; 53 ssize_t out_len; 54 int ret = -1; 55 56 buf = malloc(BUF_SIZE); 57 if (!buf) { 58 ERR("No memory for buffer"); 59 goto out; 60 } 61 62 fd = open(name, O_RDWR); 63 if (fd < 0) { 64 ERRS("Unable to open %s", name); 65 goto free_buf; 66 } 67 68 in_len = lseek(fd, 0, SEEK_END); 69 if (in_len < 0) 70 goto close; 71 72 if (!pad_to_stdout) 73 outfd = fd; 74 else 75 outfd = STDOUT_FILENO; 76 77 memset(buf, '\xff', BUF_SIZE); 78 79 in_len += xtra_offset; 80 81 out_len = in_len; 82 while (pad_mask) { 83 uint32_t mask; 84 ssize_t t; 85 int i; 86 87 for (i = 10; i < 32; i++) { 88 mask = 1UL << i; 89 if (pad_mask & mask) 90 break; 91 } 92 93 in_len = ALIGN(in_len, mask); 94 95 for (i = 10; i < 32; i++) { 96 mask = 1UL << i; 97 if ((in_len & (mask - 1)) == 0) 98 pad_mask &= ~mask; 99 } 100 101 fprintf(stderr, "padding image to %08x\n", (unsigned int) in_len - xtra_offset); 102 103 while (out_len < in_len) { 104 ssize_t len; 105 106 len = in_len - out_len; 107 if (len > BUF_SIZE) 108 len = BUF_SIZE; 109 110 t = write(outfd, buf, len); 111 if (t != len) { 112 ERRS("Unable to write to %s", name); 113 goto close; 114 } 115 116 out_len += len; 117 } 118 119 /* write out the JFFS end-of-filesystem marker */ 120 t = write(outfd, pad, pad_len); 121 if (t != pad_len) { 122 ERRS("Unable to write to %s", name); 123 goto close; 124 } 125 out_len += pad_len; 126 } 127 128 ret = 0; 129 130close: 131 close(fd); 132free_buf: 133 free(buf); 134out: 135 return ret; 136} 137 138static int usage(void) 139{ 140 fprintf(stderr, 141 "Usage: %s file [<options>] [pad0] [pad1] [padN]\n" 142 "Options:\n" 143 " -x <offset>: Add an extra offset for padding data\n" 144 " -J: Use a fake big-endian jffs2 padding element instead of EOF\n" 145 " This is used to work around broken boot loaders that\n" 146 " try to parse the entire firmware area as one big jffs2\n" 147 " -j: (like -J, but little-endian instead of big-endian)\n" 148 " -c: write padding to stdout\n" 149 "\n", 150 progname); 151 return EXIT_FAILURE; 152} 153 154int main(int argc, char* argv[]) 155{ 156 char *image; 157 uint32_t pad_mask; 158 int ret = EXIT_FAILURE; 159 int err; 160 int ch, i; 161 162 progname = basename(argv[0]); 163 164 if (argc < 2) 165 return usage(); 166 167 image = argv[1]; 168 argv++; 169 argc--; 170 171 pad_mask = 0; 172 while ((ch = getopt(argc, argv, "x:Jjc")) != -1) { 173 switch (ch) { 174 case 'x': 175 xtra_offset = strtoul(optarg, NULL, 0); 176 fprintf(stderr, "assuming %u bytes offset\n", 177 xtra_offset); 178 break; 179 case 'J': 180 pad = jffs2_pad_be; 181 pad_len = sizeof(jffs2_pad_be) - 1; 182 break; 183 case 'j': 184 pad = jffs2_pad_le; 185 pad_len = sizeof(jffs2_pad_le) - 1; 186 break; 187 case 'c': 188 pad_to_stdout = true; 189 break; 190 default: 191 return usage(); 192 } 193 } 194 195 for (i = optind; i < argc; i++) 196 pad_mask |= strtoul(argv[i], NULL, 0) * 1024; 197 198 if (pad_mask == 0) 199 pad_mask = (4 * 1024) | (8 * 1024) | (64 * 1024) | 200 (128 * 1024); 201 202 err = pad_image(image, pad_mask); 203 if (err) 204 goto out; 205 206 ret = EXIT_SUCCESS; 207 208out: 209 return ret; 210} 211