arch/all-pc/boot/grub2-aros/util/garbage-gen.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2013  Free Software Foundation, Inc.
   4  *
   5  *  GRUB is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 /* Standard random generator is slow. For FS testing we need just some
  20    garbage files, we don't need them to be high-quality random.
  21  */
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <time.h>
  26 #include <sys/time.h>
  27
  28 static unsigned long long buffer[1048576];
  29
  30 int
  31 main (int argc, char **argv)
  32 {
  33   unsigned long long high = 0, low = 1;
  34   unsigned long i, j;
  35   unsigned long long cnt = strtoull (argv[1], 0, 0);
  36   struct timeval tv;
  37   gettimeofday (&tv, NULL);
  38   high = tv.tv_sec;
  39   low = tv.tv_usec;
  40   if (!high)
  41     high = 1;
  42   if (!low)
  43     low = 2;
  44
  45   for (j = 0; j < (cnt + sizeof (buffer) - 1)  / sizeof (buffer); j++)
  46     {
  47       for (i = 0; i < sizeof (buffer) / sizeof (buffer[0]); i += 2)
  48         {
  49           int c1 = 0, c2 = 0;
  50           buffer[i] = low;
  51           buffer[i+1] = high;
  52           if (low & (1ULL << 63))
  53             c1 = 1;
  54           low <<= 1;
  55           if (high & (1ULL << 63))
  56             c2 = 1;
  57           high = (high << 1) | c1;
  58           if (c2)
  59             low ^= 0x87;
  60         }
  61       if (sizeof (buffer) < cnt - sizeof (buffer) * j)
  62         fwrite (buffer, 1, sizeof (buffer), stdout);
  63       else
  64         fwrite (buffer, 1, cnt - sizeof (buffer) * j, stdout);
  65     }
  66   return 0;
  67 }