tools/mkenvimage.c

   1 /*
   2  * (C) Copyright 2011 Free Electrons
   3  * David Wagner <david.wagner@free-electrons.com>
   4  *
   5  * Inspired from envcrc.c:
   6  * (C) Copyright 2001
   7  * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
   8  *
   9  * SPDX-License-Identifier:     GPL-2.0+
  10  */
  11
  12 #include <errno.h>
  13 #include <fcntl.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <stdint.h>
  17 #include <string.h>
  18 #include <unistd.h>
  19 #include <libgen.h>
  20 #include <sys/types.h>
  21 #include <sys/stat.h>
  22 #include <sys/mman.h>
  23
  24 #include "compiler.h"
  25 #include <u-boot/crc.h>
  26 #include <version.h>
  27
  28 #define CRC_SIZE sizeof(uint32_t)
  29
  30 static void usage(const char *exec_name)
  31 {
  32         fprintf(stderr, "%s [-h] [-r] [-b] [-p <byte>] -s <environment partition size> -o <output> <input file>\n"
  33                "\n"
  34                "This tool takes a key=value input file (same as would a `printenv' show) and generates the corresponding environment image, ready to be flashed.\n"
  35                "\n"
  36                "\tThe input file is in format:\n"
  37                "\t\tkey1=value1\n"
  38                "\t\tkey2=value2\n"
  39                "\t\t...\n"
  40                "\tEmpty lines are skipped, and lines with a # in the first\n"
  41                "\tcolumn are treated as comments (also skipped).\n"
  42                "\t-r : the environment has multiple copies in flash\n"
  43                "\t-b : the target is big endian (default is little endian)\n"
  44                "\t-p <byte> : fill the image with <byte> bytes instead of 0xff bytes\n"
  45                "\t-V : print version information and exit\n"
  46                "\n"
  47                "If the input file is \"-\", data is read from standard input\n",
  48                exec_name);
  49 }
  50
  51 long int xstrtol(const char *s)
  52 {
  53         long int tmp;
  54
  55         errno = 0;
  56         tmp = strtol(s, NULL, 0);
  57         if (!errno)
  58                 return tmp;
  59
  60         if (errno == ERANGE)
  61                 fprintf(stderr, "Bad integer format: %s\n",  s);
  62         else
  63                 fprintf(stderr, "Error while parsing %s: %s\n", s,
  64                                 strerror(errno));
  65
  66         exit(EXIT_FAILURE);
  67 }
  68
  69 int main(int argc, char **argv)
  70 {
  71         uint32_t crc, targetendian_crc;
  72         const char *txt_filename = NULL, *bin_filename = NULL;
  73         int txt_fd, bin_fd;
  74         unsigned char *dataptr, *envptr;
  75         unsigned char *filebuf = NULL;
  76         unsigned int filesize = 0, envsize = 0, datasize = 0;
  77         int bigendian = 0;
  78         int redundant = 0;
  79         unsigned char padbyte = 0xff;
  80
  81         int option;
  82         int ret = EXIT_SUCCESS;
  83
  84         struct stat txt_file_stat;
  85
  86         int fp, ep;
  87         const char *prg;
  88
  89         prg = basename(argv[0]);
  90
  91         /* Turn off getopt()'s internal error message */
  92         opterr = 0;
  93
  94         /* Parse the cmdline */
  95         while ((option = getopt(argc, argv, ":s:o:rbp:hV")) != -1) {
  96                 switch (option) {
  97                 case 's':
  98                         datasize = xstrtol(optarg);
  99                         break;
 100                 case 'o':
 101                         bin_filename = strdup(optarg);
 102                         if (!bin_filename) {
 103                                 fprintf(stderr, "Can't strdup() the output filename\n");
 104                                 return EXIT_FAILURE;
 105                         }
 106                         break;
 107                 case 'r':
 108                         redundant = 1;
 109                         break;
 110                 case 'b':
 111                         bigendian = 1;
 112                         break;
 113                 case 'p':
 114                         padbyte = xstrtol(optarg);
 115                         break;
 116                 case 'h':
 117                         usage(prg);
 118                         return EXIT_SUCCESS;
 119                 case 'V':
 120                         printf("%s version %s\n", prg, PLAIN_VERSION);
 121                         return EXIT_SUCCESS;
 122                 case ':':
 123                         fprintf(stderr, "Missing argument for option -%c\n",
 124                                 optopt);
 125                         usage(prg);
 126                         return EXIT_FAILURE;
 127                 default:
 128                         fprintf(stderr, "Wrong option -%c\n", optopt);
 129                         usage(prg);
 130                         return EXIT_FAILURE;
 131                 }
 132         }
 133
 134         /* Check datasize and allocate the data */
 135         if (datasize == 0) {
 136                 fprintf(stderr, "Please specify the size of the environment partition.\n");
 137                 usage(prg);
 138                 return EXIT_FAILURE;
 139         }
 140
 141         dataptr = malloc(datasize * sizeof(*dataptr));
 142         if (!dataptr) {
 143                 fprintf(stderr, "Can't alloc %d bytes for dataptr.\n",
 144                                 datasize);
 145                 return EXIT_FAILURE;
 146         }
 147
 148         /*
 149          * envptr points to the beginning of the actual environment (after the
 150          * crc and possible `redundant' byte
 151          */
 152         envsize = datasize - (CRC_SIZE + redundant);
 153         envptr = dataptr + CRC_SIZE + redundant;
 154
 155         /* Pad the environment with the padding byte */
 156         memset(envptr, padbyte, envsize);
 157
 158         /* Open the input file ... */
 159         if (optind >= argc || strcmp(argv[optind], "-") == 0) {
 160                 int readbytes = 0;
 161                 int readlen = sizeof(*envptr) * 4096;
 162                 txt_fd = STDIN_FILENO;
 163
 164                 do {
 165                         filebuf = realloc(filebuf, readlen);
 166                         if (!filebuf) {
 167                                 fprintf(stderr, "Can't realloc memory for the input file buffer\n");
 168                                 return EXIT_FAILURE;
 169                         }
 170                         readbytes = read(txt_fd, filebuf + filesize, readlen);
 171                         if (errno) {
 172                                 fprintf(stderr, "Error while reading stdin: %s\n",
 173                                                 strerror(errno));
 174                                 return EXIT_FAILURE;
 175                         }
 176                         filesize += readbytes;
 177                 } while (readbytes == readlen);
 178
 179         } else {
 180                 txt_filename = argv[optind];
 181                 txt_fd = open(txt_filename, O_RDONLY);
 182                 if (txt_fd == -1) {
 183                         fprintf(stderr, "Can't open \"%s\": %s\n",
 184                                         txt_filename, strerror(errno));
 185                         return EXIT_FAILURE;
 186                 }
 187                 /* ... and check it */
 188                 ret = fstat(txt_fd, &txt_file_stat);
 189                 if (ret == -1) {
 190                         fprintf(stderr, "Can't stat() on \"%s\": %s\n",
 191                                         txt_filename, strerror(errno));
 192                         return EXIT_FAILURE;
 193                 }
 194
 195                 filesize = txt_file_stat.st_size;
 196
 197                 filebuf = mmap(NULL, sizeof(*envptr) * filesize, PROT_READ,
 198                                MAP_PRIVATE, txt_fd, 0);
 199                 if (filebuf == MAP_FAILED) {
 200                         fprintf(stderr, "mmap (%zu bytes) failed: %s\n",
 201                                         sizeof(*envptr) * filesize,
 202                                         strerror(errno));
 203                         fprintf(stderr, "Falling back to read()\n");
 204
 205                         filebuf = malloc(sizeof(*envptr) * filesize);
 206                         ret = read(txt_fd, filebuf, sizeof(*envptr) * filesize);
 207                         if (ret != sizeof(*envptr) * filesize) {
 208                                 fprintf(stderr, "Can't read the whole input file (%zu bytes): %s\n",
 209                                         sizeof(*envptr) * filesize,
 210                                         strerror(errno));
 211
 212                                 return EXIT_FAILURE;
 213                         }
 214                 }
 215                 ret = close(txt_fd);
 216         }
 217
 218         /* Parse a byte at time until reaching the file OR until the environment fills
 219          * up. Check ep against envsize - 1 to allow for extra trailing '\0'. */
 220         for (fp = 0, ep = 0 ; fp < filesize && ep < envsize - 1; fp++) {
 221                 if (filebuf[fp] == '\n') {
 222                         if (fp == 0 || filebuf[fp-1] == '\n') {
 223                                 /*
 224                                  * Skip empty lines.
 225                                  */
 226                                 continue;
 227                         } else if (filebuf[fp-1] == '\\') {
 228                                 /*
 229                                  * Embedded newline in a variable.
 230                                  *
 231                                  * The backslash was added to the envptr; rewind
 232                                  * and replace it with a newline
 233                                  */
 234                                 ep--;
 235                                 envptr[ep++] = '\n';
 236                         } else {
 237                                 /* End of a variable */
 238                                 envptr[ep++] = '\0';
 239                         }
 240                 } else if ((fp == 0 || filebuf[fp-1] == '\n') && filebuf[fp] == '#') {
 241                         /* Comment, skip the line. */
 242                         while (++fp < filesize && filebuf[fp] != '\n')
 243                         continue;
 244                 } else {
 245                         envptr[ep++] = filebuf[fp];
 246                 }
 247         }
 248         /* If there are more bytes in the file still, it means the env filled up
 249          * before parsing the whole file.  Eat comments & whitespace here to see if
 250          * there was anything meaning full left in the file, and if so, throw a error
 251          * and exit. */
 252         for( ; fp < filesize; fp++ )
 253         {
 254                 if (filebuf[fp] == '\n') {
 255                         if (fp == 0 || filebuf[fp-1] == '\n') {
 256                                 /* Ignore blank lines */
 257                                 continue;
 258                         }
 259                 } else if ((fp == 0 || filebuf[fp-1] == '\n') && filebuf[fp] == '#') {
 260                         while (++fp < filesize && filebuf[fp] != '\n')
 261                         continue;
 262                 } else {
 263                         fprintf(stderr, "The environment file is too large for the target environment storage\n");
 264                         return EXIT_FAILURE;
 265                 }
 266         }
 267         /*
 268          * Make sure there is a final '\0'
 269          * And do it again on the next byte to mark the end of the environment.
 270          */
 271         if (envptr[ep-1] != '\0') {
 272                 envptr[ep++] = '\0';
 273                 /*
 274                  * The text file doesn't have an ending newline.  We need to
 275                  * check the env size again to make sure we have room for two \0
 276                  */
 277                 if (ep >= envsize) {
 278                         fprintf(stderr, "The environment file is too large for the target environment storage\n");
 279                         return EXIT_FAILURE;
 280                 }
 281                 envptr[ep] = '\0';
 282         } else {
 283                 envptr[ep] = '\0';
 284         }
 285
 286         /* Computes the CRC and put it at the beginning of the data */
 287         crc = crc32(0, envptr, envsize);
 288         targetendian_crc = bigendian ? cpu_to_be32(crc) : cpu_to_le32(crc);
 289
 290         memcpy(dataptr, &targetendian_crc, sizeof(targetendian_crc));
 291         if (redundant)
 292                 dataptr[sizeof(targetendian_crc)] = 1;
 293
 294         if (!bin_filename || strcmp(bin_filename, "-") == 0) {
 295                 bin_fd = STDOUT_FILENO;
 296         } else {
 297                 bin_fd = creat(bin_filename, S_IRUSR | S_IWUSR | S_IRGRP |
 298                                              S_IWGRP);
 299                 if (bin_fd == -1) {
 300                         fprintf(stderr, "Can't open output file \"%s\": %s\n",
 301                                         bin_filename, strerror(errno));
 302                         return EXIT_FAILURE;
 303                 }
 304         }
 305
 306         if (write(bin_fd, dataptr, sizeof(*dataptr) * datasize) !=
 307                         sizeof(*dataptr) * datasize) {
 308                 fprintf(stderr, "write() failed: %s\n", strerror(errno));
 309                 return EXIT_FAILURE;
 310         }
 311
 312         ret = close(bin_fd);
 313
 314         return ret;
 315 }