commands/crc.c

   1 /*
   2  * crc.c - Calculate a crc32 checksum of a memory area
   3  *
   4  * Copyright (c) 2007 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2
  11  * as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <common.h>
  24 #include <command.h>
  25 #include <fs.h>
  26 #include <getopt.h>
  27 #include <fcntl.h>
  28 #include <errno.h>
  29 #include <xfuncs.h>
  30 #include <malloc.h>
  31 #include <linux/ctype.h>
  32
  33 static int do_crc(struct command *cmdtp, int argc, char *argv[])
  34 {
  35         ulong start = 0, size = ~0, total = 0;
  36         ulong crc = 0, vcrc = 0;
  37         char *filename = "/dev/mem";
  38         char *buf;
  39         int fd, opt, err = 0, filegiven = 0, verify = 0, now;
  40
  41         while((opt = getopt(argc, argv, "f:v:")) > 0) {
  42                 switch(opt) {
  43                 case 'f':
  44                         filename = optarg;
  45                         filegiven = 1;
  46                         break;
  47                 case 'v':
  48                         verify = 1;
  49                         vcrc = simple_strtoul(optarg, NULL, 0);
  50                         break;
  51                 }
  52         }
  53
  54         if (!filegiven && optind == argc)
  55                 return COMMAND_ERROR_USAGE;
  56
  57         if (optind < argc) {
  58                 if (parse_area_spec(argv[optind], &start, &size)) {
  59                         printf("could not parse area description: %s\n", argv[optind]);
  60                         return 1;
  61                 }
  62         }
  63
  64         fd = open(filename, O_RDONLY);
  65         if (fd < 0) {
  66                 printf("open %s: %s\n", filename, errno_str());
  67                 return 1;
  68         }
  69
  70         if (start > 0) {
  71                 if (lseek(fd, start, SEEK_SET) == -1) {
  72                         perror("lseek");
  73                         err = 1;
  74                         goto out;
  75                 }
  76         }
  77
  78         buf = xmalloc(4096);
  79
  80         while (size) {
  81                 now = min((ulong)4096, size);
  82                 now = read(fd, buf, now);
  83                 if (now < 0) {
  84                         perror("read");
  85                         goto out_free;
  86                 }
  87                 if (!now)
  88                         break;
  89                 crc = crc32(crc, buf, now);
  90                 size -= now;
  91                 total += now;
  92         }
  93
  94         printf ("CRC32 for %s 0x%08lx ... 0x%08lx ==> 0x%08lx",
  95                         filename, start, start + total - 1, crc);
  96
  97         if (verify && crc != vcrc) {
  98                 printf(" != 0x%08x ** ERROR **", vcrc);
  99                 err = 1;
 100         }
 101
 102         printf("\n");
 103
 104 out_free:
 105         free(buf);
 106 out:
 107         close(fd);
 108
 109         return err;
 110 }
 111
 112 static const __maybe_unused char cmd_crc_help[] =
 113 "Usage: crc32 [OPTION] [AREA]\n"
 114 "Calculate a crc32 checksum of a memory area\n"
 115 "Options:\n"
 116 "  -f <file>   Use file instead of memory\n"
 117 "  -v <crc>    Verfify\n";
 118
 119 BAREBOX_CMD_START(crc32)
 120         .cmd            = do_crc,
 121         .usage          = "crc32 checksum calculation",
 122         BAREBOX_CMD_HELP(cmd_crc_help)
 123 BAREBOX_CMD_END
 124