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  * See file CREDITS for list of people who contributed to this
  10  * project.
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License as
  14  * published by the Free Software Foundation; either version 2 of
  15  * the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  25  * MA 02111-1307 USA
  26  */
  27
  28 #include <errno.h>
  29 #include <fcntl.h>
  30 #include <stdio.h>
  31 #include <stdint.h>
  32 #include <string.h>
  33 #include <unistd.h>
  34 #include <compiler.h>
  35 #include <sys/types.h>
  36 #include <sys/stat.h>
  37
  38 #include <u-boot/crc.h>
  39
  40 #define CRC_SIZE sizeof(uint32_t)
  41
  42 static void usage(const char *exec_name)
  43 {
  44         fprintf(stderr, "%s [-h] [-r] [-b] [-p <byte>] "
  45                "-s <environment partition size> -o <output> <input file>\n"
  46                "\n"
  47                "This tool takes a key=value input file (same as would a "
  48                "`printenv' show) and generates the corresponding environment "
  49                "image, ready to be flashed.\n"
  50                "\n"
  51                "\tThe input file is in format:\n"
  52                "\t\tkey1=value1\n"
  53                "\t\tkey2=value2\n"
  54                "\t\t...\n"
  55                "\t-r : the environment has multiple copies in flash\n"
  56                "\t-b : the target is big endian (default is little endian)\n"
  57                "\t-p <byte> : fill the image with <byte> bytes instead of "
  58                "0xff bytes\n"
  59                "\n"
  60                "If the input file is \"-\", data is read from standard input\n",
  61                exec_name);
  62 }
  63
  64 int main(int argc, char **argv)
  65 {
  66         uint32_t crc, targetendian_crc;
  67         const char *txt_filename = NULL, *bin_filename = NULL;
  68         int txt_fd, bin_fd;
  69         unsigned char *dataptr, *envptr;
  70         unsigned char *filebuf = NULL;
  71         unsigned int filesize = 0, envsize = 0, datasize = 0;
  72         int bigendian = 0;
  73         int redundant = 0;
  74         unsigned char padbyte = 0xff;
  75
  76         int option;
  77         int ret = EXIT_SUCCESS;
  78
  79         struct stat txt_file_stat;
  80
  81         int fp, ep;
  82
  83         /* Parse the cmdline */
  84         while ((option = getopt(argc, argv, "s:o:rbp:h")) != -1) {
  85                 switch (option) {
  86                 case 's':
  87                         datasize = strtol(optarg, NULL, 0);
  88                         break;
  89                 case 'o':
  90                         bin_filename = strdup(optarg);
  91                         if (!bin_filename) {
  92                                 fprintf(stderr, "Can't strdup() the output "
  93                                                 "filename\n");
  94                                 return EXIT_FAILURE;
  95                         }
  96                         break;
  97                 case 'r':
  98                         redundant = 1;
  99                         break;
 100                 case 'b':
 101                         bigendian = 1;
 102                         break;
 103                 case 'p':
 104                         padbyte = strtol(optarg, NULL, 0);
 105                         break;
 106                 case 'h':
 107                         usage(argv[0]);
 108                         return EXIT_SUCCESS;
 109                 default:
 110                         fprintf(stderr, "Wrong option -%c\n", option);
 111                         usage(argv[0]);
 112                         return EXIT_FAILURE;
 113                 }
 114         }
 115
 116         /* Check datasize and allocate the data */
 117         if (datasize == 0) {
 118                 fprintf(stderr,
 119                         "Please specify the size of the environment "
 120                         "partition.\n");
 121                 usage(argv[0]);
 122                 return EXIT_FAILURE;
 123         }
 124
 125         dataptr = malloc(datasize * sizeof(*dataptr));
 126         if (!dataptr) {
 127                 fprintf(stderr, "Can't alloc dataptr.\n");
 128                 return EXIT_FAILURE;
 129         }
 130
 131         /*
 132          * envptr points to the beginning of the actual environment (after the
 133          * crc and possible `redundant' bit
 134          */
 135         envsize = datasize - (CRC_SIZE + redundant);
 136         envptr = dataptr + CRC_SIZE + redundant;
 137
 138         /* Pad the environment with the padding byte */
 139         memset(envptr, padbyte, envsize);
 140
 141         /* Open the input file ... */
 142         if (optind >= argc) {
 143                 fprintf(stderr, "Please specify an input filename\n");
 144                 return EXIT_FAILURE;
 145         }
 146
 147         txt_filename = argv[optind];
 148         if (strcmp(txt_filename, "-") == 0) {
 149                 int readbytes = 0;
 150                 int readlen = sizeof(*envptr) * 2048;
 151                 txt_fd = STDIN_FILENO;
 152
 153                 do {
 154                         filebuf = realloc(filebuf, readlen);
 155                         readbytes = read(txt_fd, filebuf + filesize, readlen);
 156                         filesize += readbytes;
 157                 } while (readbytes == readlen);
 158
 159         } else {
 160                 txt_fd = open(txt_filename, O_RDONLY);
 161                 if (txt_fd == -1) {
 162                         fprintf(stderr, "Can't open \"%s\": %s\n",
 163                                         txt_filename, strerror(errno));
 164                         return EXIT_FAILURE;
 165                 }
 166                 /* ... and check it */
 167                 ret = fstat(txt_fd, &txt_file_stat);
 168                 if (ret == -1) {
 169                         fprintf(stderr, "Can't stat() on \"%s\": "
 170                                         "%s\n", txt_filename, strerror(errno));
 171                         return EXIT_FAILURE;
 172                 }
 173
 174                 filesize = txt_file_stat.st_size;
 175                 /* Read the raw input file and transform it */
 176                 filebuf = malloc(sizeof(*envptr) * filesize);
 177                 ret = read(txt_fd, filebuf, sizeof(*envptr) * filesize);
 178                 if (ret != sizeof(*envptr) * filesize) {
 179                         fprintf(stderr, "Can't read the whole input file\n");
 180                         return EXIT_FAILURE;
 181                 }
 182                 ret = close(txt_fd);
 183         }
 184         /*
 185          * The right test to do is "=>" (not ">") because of the additional
 186          * ending \0. See below.
 187          */
 188         if (filesize >= envsize) {
 189                 fprintf(stderr, "The input file is larger than the "
 190                                 "environment partition size\n");
 191                 return EXIT_FAILURE;
 192         }
 193
 194         /* Replace newlines separating variables with \0 */
 195         for (fp = 0, ep = 0 ; fp < filesize ; fp++) {
 196                 if (filebuf[fp] == '\n') {
 197                         if (fp == 0) {
 198                                 /*
 199                                  * Newline at the beginning of the file ?
 200                                  * Ignore it.
 201                                  */
 202                                 continue;
 203                         } else if (filebuf[fp-1] == '\\') {
 204                                 /*
 205                                  * Embedded newline in a variable.
 206                                  *
 207                                  * The backslash was added to the envptr ;
 208                                  * rewind and replace it with a newline
 209                                  */
 210                                 ep--;
 211                                 envptr[ep++] = '\n';
 212                         } else {
 213                                 /* End of a variable */
 214                                 envptr[ep++] = '\0';
 215                         }
 216                 } else if (filebuf[fp] == '#') {
 217                         if (fp != 0 && filebuf[fp-1] == '\n') {
 218                                 /* This line is a comment, let's skip it */
 219                                 while (fp < txt_file_stat.st_size && fp++ &&
 220                                        filebuf[fp] != '\n');
 221                         } else {
 222                                 envptr[ep++] = filebuf[fp];
 223                         }
 224                 } else {
 225                         envptr[ep++] = filebuf[fp];
 226                 }
 227         }
 228         /*
 229          * Make sure there is a final '\0'
 230          * And do it again on the next byte to mark the end of the environment.
 231          */
 232         if (envptr[ep-1] != '\0') {
 233                 envptr[ep++] = '\0';
 234                 /*
 235                  * The text file doesn't have an ending newline.  We need to
 236                  * check the env size again to make sure we have room for two \0
 237                  */
 238                 if (ep >= envsize) {
 239                         fprintf(stderr, "The environment file is too large for "
 240                                         "the target environment storage\n");
 241                         return EXIT_FAILURE;
 242                 }
 243                 envptr[ep] = '\0';
 244         } else {
 245                 envptr[ep] = '\0';
 246         }
 247
 248         /* Computes the CRC and put it at the beginning of the data */
 249         crc = crc32(0, envptr, envsize);
 250         targetendian_crc = bigendian ? cpu_to_be32(crc) : cpu_to_le32(crc);
 251
 252         memcpy(dataptr, &targetendian_crc, sizeof(uint32_t));
 253
 254         bin_fd = creat(bin_filename, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
 255         if (bin_fd == -1) {
 256                 fprintf(stderr, "Can't open output file \"%s\": %s\n",
 257                                 bin_filename, strerror(errno));
 258                 return EXIT_FAILURE;
 259         }
 260
 261         if (write(bin_fd, dataptr, sizeof(*dataptr) * datasize) !=
 262                         sizeof(*dataptr) * datasize) {
 263                 fprintf(stderr, "write() failed: %s\n", strerror(errno));
 264                 return EXIT_FAILURE;
 265         }
 266
 267         ret = close(bin_fd);
 268
 269         return ret;
 270 }