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 <u-boot/crc.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 #define CHUNK_SIZE 4096
  70
  71 int main(int argc, char **argv)
  72 {
  73         uint32_t crc, targetendian_crc;
  74         const char *bin_filename = NULL;
  75         int txt_fd, bin_fd;
  76         unsigned char *dataptr, *envptr;
  77         unsigned char *filebuf = NULL;
  78         unsigned int filesize = 0, envsize = 0, datasize = 0;
  79         int bigendian = 0;
  80         int redundant = 0;
  81         unsigned char padbyte = 0xff;
  82         int readbytes = 0;
  83
  84         int option;
  85         int ret = EXIT_SUCCESS;
  86
  87         int fp, ep;
  88         const char *prg;
  89
  90         prg = basename(argv[0]);
  91
  92         /* Turn off getopt()'s internal error message */
  93         opterr = 0;
  94
  95         /* Parse the cmdline */
  96         while ((option = getopt(argc, argv, ":s:o:rbp:hV")) != -1) {
  97                 switch (option) {
  98                 case 's':
  99                         datasize = xstrtol(optarg);
 100                         break;
 101                 case 'o':
 102                         bin_filename = strdup(optarg);
 103                         if (!bin_filename) {
 104                                 fprintf(stderr, "Can't strdup() the output filename\n");
 105                                 return EXIT_FAILURE;
 106                         }
 107                         break;
 108                 case 'r':
 109                         redundant = 1;
 110                         break;
 111                 case 'b':
 112                         bigendian = 1;
 113                         break;
 114                 case 'p':
 115                         padbyte = xstrtol(optarg);
 116                         break;
 117                 case 'h':
 118                         usage(prg);
 119                         return EXIT_SUCCESS;
 120                 case 'V':
 121                         printf("%s version %s\n", prg, PLAIN_VERSION);
 122                         return EXIT_SUCCESS;
 123                 case ':':
 124                         fprintf(stderr, "Missing argument for option -%c\n",
 125                                 optopt);
 126                         usage(prg);
 127                         return EXIT_FAILURE;
 128                 default:
 129                         fprintf(stderr, "Wrong option -%c\n", optopt);
 130                         usage(prg);
 131                         return EXIT_FAILURE;
 132                 }
 133         }
 134
 135         /* Check datasize and allocate the data */
 136         if (datasize == 0) {
 137                 fprintf(stderr, "Please specify the size of the environment partition.\n");
 138                 usage(prg);
 139                 return EXIT_FAILURE;
 140         }
 141
 142         dataptr = malloc(datasize * sizeof(*dataptr));
 143         if (!dataptr) {
 144                 fprintf(stderr, "Can't alloc %d bytes for dataptr.\n",
 145                                 datasize);
 146                 return EXIT_FAILURE;
 147         }
 148
 149         /*
 150          * envptr points to the beginning of the actual environment (after the
 151          * crc and possible `redundant' byte
 152          */
 153         envsize = datasize - (CRC_SIZE + redundant);
 154         envptr = dataptr + CRC_SIZE + redundant;
 155
 156         /* Pad the environment with the padding byte */
 157         memset(envptr, padbyte, envsize);
 158
 159         /* Open the input file ... */
 160         if (optind >= argc || strcmp(argv[optind], "-") == 0) {
 161                 txt_fd = STDIN_FILENO;
 162         } else {
 163                 txt_fd = open(argv[optind], O_RDONLY);
 164                 if (txt_fd == -1) {
 165                         fprintf(stderr, "Can't open \"%s\": %s\n",
 166                                         argv[optind], strerror(errno));
 167                         return EXIT_FAILURE;
 168                 }
 169         }
 170
 171         do {
 172                 filebuf = realloc(filebuf, filesize + CHUNK_SIZE);
 173                 if (!filebuf) {
 174                         fprintf(stderr, "Can't realloc memory for the input file buffer\n");
 175                         return EXIT_FAILURE;
 176                 }
 177                 readbytes = read(txt_fd, filebuf + filesize, CHUNK_SIZE);
 178                 if (readbytes < 0) {
 179                         fprintf(stderr, "Error while reading: %s\n",
 180                                 strerror(errno));
 181                         return EXIT_FAILURE;
 182                 }
 183                 filesize += readbytes;
 184         } while (readbytes > 0);
 185
 186         if (txt_fd != STDIN_FILENO)
 187                 ret = close(txt_fd);
 188
 189         /* Parse a byte at time until reaching the file OR until the environment fills
 190          * up. Check ep against envsize - 1 to allow for extra trailing '\0'. */
 191         for (fp = 0, ep = 0 ; fp < filesize && ep < envsize - 1; fp++) {
 192                 if (filebuf[fp] == '\n') {
 193                         if (fp == 0 || filebuf[fp-1] == '\n') {
 194                                 /*
 195                                  * Skip empty lines.
 196                                  */
 197                                 continue;
 198                         } else if (filebuf[fp-1] == '\\') {
 199                                 /*
 200                                  * Embedded newline in a variable.
 201                                  *
 202                                  * The backslash was added to the envptr; rewind
 203                                  * and replace it with a newline
 204                                  */
 205                                 ep--;
 206                                 envptr[ep++] = '\n';
 207                         } else {
 208                                 /* End of a variable */
 209                                 envptr[ep++] = '\0';
 210                         }
 211                 } else if ((fp == 0 || filebuf[fp-1] == '\n') && filebuf[fp] == '#') {
 212                         /* Comment, skip the line. */
 213                         while (++fp < filesize && filebuf[fp] != '\n')
 214                         continue;
 215                 } else {
 216                         envptr[ep++] = filebuf[fp];
 217                 }
 218         }
 219         /* If there are more bytes in the file still, it means the env filled up
 220          * before parsing the whole file.  Eat comments & whitespace here to see if
 221          * there was anything meaning full left in the file, and if so, throw a error
 222          * and exit. */
 223         for( ; fp < filesize; fp++ )
 224         {
 225                 if (filebuf[fp] == '\n') {
 226                         if (fp == 0 || filebuf[fp-1] == '\n') {
 227                                 /* Ignore blank lines */
 228                                 continue;
 229                         }
 230                 } else if ((fp == 0 || filebuf[fp-1] == '\n') && filebuf[fp] == '#') {
 231                         while (++fp < filesize && filebuf[fp] != '\n')
 232                         continue;
 233                 } else {
 234                         fprintf(stderr, "The environment file is too large for the target environment storage\n");
 235                         return EXIT_FAILURE;
 236                 }
 237         }
 238         /*
 239          * Make sure there is a final '\0'
 240          * And do it again on the next byte to mark the end of the environment.
 241          */
 242         if (envptr[ep-1] != '\0') {
 243                 envptr[ep++] = '\0';
 244                 /*
 245                  * The text file doesn't have an ending newline.  We need to
 246                  * check the env size again to make sure we have room for two \0
 247                  */
 248                 if (ep >= envsize) {
 249                         fprintf(stderr, "The environment file is too large for the target environment storage\n");
 250                         return EXIT_FAILURE;
 251                 }
 252                 envptr[ep] = '\0';
 253         } else {
 254                 envptr[ep] = '\0';
 255         }
 256
 257         /* Computes the CRC and put it at the beginning of the data */
 258         crc = crc32(0, envptr, envsize);
 259         targetendian_crc = bigendian ? cpu_to_be32(crc) : cpu_to_le32(crc);
 260
 261         memcpy(dataptr, &targetendian_crc, sizeof(targetendian_crc));
 262         if (redundant)
 263                 dataptr[sizeof(targetendian_crc)] = 1;
 264
 265         if (!bin_filename || strcmp(bin_filename, "-") == 0) {
 266                 bin_fd = STDOUT_FILENO;
 267         } else {
 268                 bin_fd = creat(bin_filename, S_IRUSR | S_IWUSR | S_IRGRP |
 269                                              S_IWGRP);
 270                 if (bin_fd == -1) {
 271                         fprintf(stderr, "Can't open output file \"%s\": %s\n",
 272                                         bin_filename, strerror(errno));
 273                         return EXIT_FAILURE;
 274                 }
 275         }
 276
 277         if (write(bin_fd, dataptr, sizeof(*dataptr) * datasize) !=
 278                         sizeof(*dataptr) * datasize) {
 279                 fprintf(stderr, "write() failed: %s\n", strerror(errno));
 280                 return EXIT_FAILURE;
 281         }
 282
 283         ret = close(bin_fd);
 284
 285         return ret;
 286 }