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                "\t-r : the environment has multiple copies in flash\n"
  41                "\t-b : the target is big endian (default is little endian)\n"
  42                "\t-p <byte> : fill the image with <byte> bytes instead of 0xff bytes\n"
  43                "\t-V : print version information and exit\n"
  44                "\n"
  45                "If the input file is \"-\", data is read from standard input\n",
  46                exec_name);
  47 }
  48
  49 long int xstrtol(const char *s)
  50 {
  51         long int tmp;
  52
  53         errno = 0;
  54         tmp = strtol(s, NULL, 0);
  55         if (!errno)
  56                 return tmp;
  57
  58         if (errno == ERANGE)
  59                 fprintf(stderr, "Bad integer format: %s\n",  s);
  60         else
  61                 fprintf(stderr, "Error while parsing %s: %s\n", s,
  62                                 strerror(errno));
  63
  64         exit(EXIT_FAILURE);
  65 }
  66
  67 int main(int argc, char **argv)
  68 {
  69         uint32_t crc, targetendian_crc;
  70         const char *txt_filename = NULL, *bin_filename = NULL;
  71         int txt_fd, bin_fd;
  72         unsigned char *dataptr, *envptr;
  73         unsigned char *filebuf = NULL;
  74         unsigned int filesize = 0, envsize = 0, datasize = 0;
  75         int bigendian = 0;
  76         int redundant = 0;
  77         unsigned char padbyte = 0xff;
  78
  79         int option;
  80         int ret = EXIT_SUCCESS;
  81
  82         struct stat txt_file_stat;
  83
  84         int fp, ep;
  85         const char *prg;
  86
  87         prg = basename(argv[0]);
  88
  89         /* Turn off getopt()'s internal error message */
  90         opterr = 0;
  91
  92         /* Parse the cmdline */
  93         while ((option = getopt(argc, argv, ":s:o:rbp:hV")) != -1) {
  94                 switch (option) {
  95                 case 's':
  96                         datasize = xstrtol(optarg);
  97                         break;
  98                 case 'o':
  99                         bin_filename = strdup(optarg);
 100                         if (!bin_filename) {
 101                                 fprintf(stderr, "Can't strdup() the output filename\n");
 102                                 return EXIT_FAILURE;
 103                         }
 104                         break;
 105                 case 'r':
 106                         redundant = 1;
 107                         break;
 108                 case 'b':
 109                         bigendian = 1;
 110                         break;
 111                 case 'p':
 112                         padbyte = xstrtol(optarg);
 113                         break;
 114                 case 'h':
 115                         usage(prg);
 116                         return EXIT_SUCCESS;
 117                 case 'V':
 118                         printf("%s version %s\n", prg, PLAIN_VERSION);
 119                         return EXIT_SUCCESS;
 120                 case ':':
 121                         fprintf(stderr, "Missing argument for option -%c\n",
 122                                 optopt);
 123                         usage(prg);
 124                         return EXIT_FAILURE;
 125                 default:
 126                         fprintf(stderr, "Wrong option -%c\n", optopt);
 127                         usage(prg);
 128                         return EXIT_FAILURE;
 129                 }
 130         }
 131
 132         /* Check datasize and allocate the data */
 133         if (datasize == 0) {
 134                 fprintf(stderr, "Please specify the size of the environment partition.\n");
 135                 usage(prg);
 136                 return EXIT_FAILURE;
 137         }
 138
 139         dataptr = malloc(datasize * sizeof(*dataptr));
 140         if (!dataptr) {
 141                 fprintf(stderr, "Can't alloc %d bytes for dataptr.\n",
 142                                 datasize);
 143                 return EXIT_FAILURE;
 144         }
 145
 146         /*
 147          * envptr points to the beginning of the actual environment (after the
 148          * crc and possible `redundant' byte
 149          */
 150         envsize = datasize - (CRC_SIZE + redundant);
 151         envptr = dataptr + CRC_SIZE + redundant;
 152
 153         /* Pad the environment with the padding byte */
 154         memset(envptr, padbyte, envsize);
 155
 156         /* Open the input file ... */
 157         if (optind >= argc || strcmp(argv[optind], "-") == 0) {
 158                 int readbytes = 0;
 159                 int readlen = sizeof(*envptr) * 4096;
 160                 txt_fd = STDIN_FILENO;
 161
 162                 do {
 163                         filebuf = realloc(filebuf, readlen);
 164                         if (!filebuf) {
 165                                 fprintf(stderr, "Can't realloc memory for the input file buffer\n");
 166                                 return EXIT_FAILURE;
 167                         }
 168                         readbytes = read(txt_fd, filebuf + filesize, readlen);
 169                         if (errno) {
 170                                 fprintf(stderr, "Error while reading stdin: %s\n",
 171                                                 strerror(errno));
 172                                 return EXIT_FAILURE;
 173                         }
 174                         filesize += readbytes;
 175                 } while (readbytes == readlen);
 176
 177         } else {
 178                 txt_filename = argv[optind];
 179                 txt_fd = open(txt_filename, O_RDONLY);
 180                 if (txt_fd == -1) {
 181                         fprintf(stderr, "Can't open \"%s\": %s\n",
 182                                         txt_filename, strerror(errno));
 183                         return EXIT_FAILURE;
 184                 }
 185                 /* ... and check it */
 186                 ret = fstat(txt_fd, &txt_file_stat);
 187                 if (ret == -1) {
 188                         fprintf(stderr, "Can't stat() on \"%s\": %s\n",
 189                                         txt_filename, strerror(errno));
 190                         return EXIT_FAILURE;
 191                 }
 192
 193                 filesize = txt_file_stat.st_size;
 194
 195                 filebuf = mmap(NULL, sizeof(*envptr) * filesize, PROT_READ,
 196                                MAP_PRIVATE, txt_fd, 0);
 197                 if (filebuf == MAP_FAILED) {
 198                         fprintf(stderr, "mmap (%zu bytes) failed: %s\n",
 199                                         sizeof(*envptr) * filesize,
 200                                         strerror(errno));
 201                         fprintf(stderr, "Falling back to read()\n");
 202
 203                         filebuf = malloc(sizeof(*envptr) * filesize);
 204                         ret = read(txt_fd, filebuf, sizeof(*envptr) * filesize);
 205                         if (ret != sizeof(*envptr) * filesize) {
 206                                 fprintf(stderr, "Can't read the whole input file (%zu bytes): %s\n",
 207                                         sizeof(*envptr) * filesize,
 208                                         strerror(errno));
 209
 210                                 return EXIT_FAILURE;
 211                         }
 212                 }
 213                 ret = close(txt_fd);
 214         }
 215         /* The +1 is for the additionnal ending \0. See below. */
 216         if (filesize + 1 > envsize) {
 217                 fprintf(stderr, "The input file is larger than the environment partition size\n");
 218                 return EXIT_FAILURE;
 219         }
 220
 221         /* Replace newlines separating variables with \0 */
 222         for (fp = 0, ep = 0 ; fp < filesize ; fp++) {
 223                 if (filebuf[fp] == '\n') {
 224                         if (ep == 0) {
 225                                 /*
 226                                  * Newlines at the beginning of the file ?
 227                                  * Ignore them.
 228                                  */
 229                                 continue;
 230                         } else if (filebuf[fp-1] == '\\') {
 231                                 /*
 232                                  * Embedded newline in a variable.
 233                                  *
 234                                  * The backslash was added to the envptr; rewind
 235                                  * and replace it with a newline
 236                                  */
 237                                 ep--;
 238                                 envptr[ep++] = '\n';
 239                         } else {
 240                                 /* End of a variable */
 241                                 envptr[ep++] = '\0';
 242                         }
 243                 } else {
 244                         envptr[ep++] = filebuf[fp];
 245                 }
 246         }
 247         /*
 248          * Make sure there is a final '\0'
 249          * And do it again on the next byte to mark the end of the environment.
 250          */
 251         if (envptr[ep-1] != '\0') {
 252                 envptr[ep++] = '\0';
 253                 /*
 254                  * The text file doesn't have an ending newline.  We need to
 255                  * check the env size again to make sure we have room for two \0
 256                  */
 257                 if (ep >= envsize) {
 258                         fprintf(stderr, "The environment file is too large for the target environment storage\n");
 259                         return EXIT_FAILURE;
 260                 }
 261                 envptr[ep] = '\0';
 262         } else {
 263                 envptr[ep] = '\0';
 264         }
 265
 266         /* Computes the CRC and put it at the beginning of the data */
 267         crc = crc32(0, envptr, envsize);
 268         targetendian_crc = bigendian ? cpu_to_be32(crc) : cpu_to_le32(crc);
 269
 270         memcpy(dataptr, &targetendian_crc, sizeof(targetendian_crc));
 271         if (redundant)
 272                 dataptr[sizeof(targetendian_crc)] = 1;
 273
 274         if (!bin_filename || strcmp(bin_filename, "-") == 0) {
 275                 bin_fd = STDOUT_FILENO;
 276         } else {
 277                 bin_fd = creat(bin_filename, S_IRUSR | S_IWUSR | S_IRGRP |
 278                                              S_IWGRP);
 279                 if (bin_fd == -1) {
 280                         fprintf(stderr, "Can't open output file \"%s\": %s\n",
 281                                         bin_filename, strerror(errno));
 282                         return EXIT_FAILURE;
 283                 }
 284         }
 285
 286         if (write(bin_fd, dataptr, sizeof(*dataptr) * datasize) !=
 287                         sizeof(*dataptr) * datasize) {
 288                 fprintf(stderr, "write() failed: %s\n", strerror(errno));
 289                 return EXIT_FAILURE;
 290         }
 291
 292         ret = close(bin_fd);
 293
 294         return ret;
 295 }