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 #define CHUNK_SIZE 4096
  69
  70 int main(int argc, char **argv)
  71 {
  72         uint32_t crc, targetendian_crc;
  73         const char *bin_filename = NULL;
  74         int txt_fd, bin_fd;
  75         unsigned char *dataptr, *envptr;
  76         unsigned char *filebuf = NULL;
  77         unsigned int filesize = 0, envsize = 0, datasize = 0;
  78         int bigendian = 0;
  79         int redundant = 0;
  80         unsigned char padbyte = 0xff;
  81         int readbytes = 0;
  82
  83         int option;
  84         int ret = EXIT_SUCCESS;
  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                 txt_fd = STDIN_FILENO;
 161         } else {
 162                 txt_fd = open(argv[optind], O_RDONLY);
 163                 if (txt_fd == -1) {
 164                         fprintf(stderr, "Can't open \"%s\": %s\n",
 165                                         argv[optind], strerror(errno));
 166                         return EXIT_FAILURE;
 167                 }
 168         }
 169
 170         do {
 171                 filebuf = realloc(filebuf, filesize + CHUNK_SIZE);
 172                 if (!filebuf) {
 173                         fprintf(stderr, "Can't realloc memory for the input file buffer\n");
 174                         return EXIT_FAILURE;
 175                 }
 176                 readbytes = read(txt_fd, filebuf + filesize, CHUNK_SIZE);
 177                 if (readbytes < 0) {
 178                         fprintf(stderr, "Error while reading: %s\n",
 179                                 strerror(errno));
 180                         return EXIT_FAILURE;
 181                 }
 182                 filesize += readbytes;
 183         } while (readbytes > 0);
 184
 185         if (txt_fd != STDIN_FILENO)
 186                 ret = close(txt_fd);
 187
 188         /* Parse a byte at time until reaching the file OR until the environment fills
 189          * up. Check ep against envsize - 1 to allow for extra trailing '\0'. */
 190         for (fp = 0, ep = 0 ; fp < filesize && ep < envsize - 1; fp++) {
 191                 if (filebuf[fp] == '\n') {
 192                         if (fp == 0 || filebuf[fp-1] == '\n') {
 193                                 /*
 194                                  * Skip empty lines.
 195                                  */
 196                                 continue;
 197                         } else if (filebuf[fp-1] == '\\') {
 198                                 /*
 199                                  * Embedded newline in a variable.
 200                                  *
 201                                  * The backslash was added to the envptr; rewind
 202                                  * and replace it with a newline
 203                                  */
 204                                 ep--;
 205                                 envptr[ep++] = '\n';
 206                         } else {
 207                                 /* End of a variable */
 208                                 envptr[ep++] = '\0';
 209                         }
 210                 } else if ((fp == 0 || filebuf[fp-1] == '\n') && filebuf[fp] == '#') {
 211                         /* Comment, skip the line. */
 212                         while (++fp < filesize && filebuf[fp] != '\n')
 213                         continue;
 214                 } else {
 215                         envptr[ep++] = filebuf[fp];
 216                 }
 217         }
 218         /* If there are more bytes in the file still, it means the env filled up
 219          * before parsing the whole file.  Eat comments & whitespace here to see if
 220          * there was anything meaning full left in the file, and if so, throw a error
 221          * and exit. */
 222         for( ; fp < filesize; fp++ )
 223         {
 224                 if (filebuf[fp] == '\n') {
 225                         if (fp == 0 || filebuf[fp-1] == '\n') {
 226                                 /* Ignore blank lines */
 227                                 continue;
 228                         }
 229                 } else if ((fp == 0 || filebuf[fp-1] == '\n') && filebuf[fp] == '#') {
 230                         while (++fp < filesize && filebuf[fp] != '\n')
 231                         continue;
 232                 } else {
 233                         fprintf(stderr, "The environment file is too large for the target environment storage\n");
 234                         return EXIT_FAILURE;
 235                 }
 236         }
 237         /*
 238          * Make sure there is a final '\0'
 239          * And do it again on the next byte to mark the end of the environment.
 240          */
 241         if (envptr[ep-1] != '\0') {
 242                 envptr[ep++] = '\0';
 243                 /*
 244                  * The text file doesn't have an ending newline.  We need to
 245                  * check the env size again to make sure we have room for two \0
 246                  */
 247                 if (ep >= envsize) {
 248                         fprintf(stderr, "The environment file is too large for the target environment storage\n");
 249                         return EXIT_FAILURE;
 250                 }
 251                 envptr[ep] = '\0';
 252         } else {
 253                 envptr[ep] = '\0';
 254         }
 255
 256         /* Computes the CRC and put it at the beginning of the data */
 257         crc = crc32(0, envptr, envsize);
 258         targetendian_crc = bigendian ? cpu_to_be32(crc) : cpu_to_le32(crc);
 259
 260         memcpy(dataptr, &targetendian_crc, sizeof(targetendian_crc));
 261         if (redundant)
 262                 dataptr[sizeof(targetendian_crc)] = 1;
 263
 264         if (!bin_filename || strcmp(bin_filename, "-") == 0) {
 265                 bin_fd = STDOUT_FILENO;
 266         } else {
 267                 bin_fd = creat(bin_filename, S_IRUSR | S_IWUSR | S_IRGRP |
 268                                              S_IWGRP);
 269                 if (bin_fd == -1) {
 270                         fprintf(stderr, "Can't open output file \"%s\": %s\n",
 271                                         bin_filename, strerror(errno));
 272                         return EXIT_FAILURE;
 273                 }
 274         }
 275
 276         if (write(bin_fd, dataptr, sizeof(*dataptr) * datasize) !=
 277                         sizeof(*dataptr) * datasize) {
 278                 fprintf(stderr, "write() failed: %s\n", strerror(errno));
 279                 return EXIT_FAILURE;
 280         }
 281
 282         ret = close(bin_fd);
 283
 284         return ret;
 285 }