tools/mkenvimage.c

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