text: /*
   * Copyright 2011, The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include <sys/types.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <sys/stat.h>
  #include <sys/ioctl.h>
  #include <sys/mount.h> /* for BLKGETSIZE */
  #include <cutils/properties.h>
  
  static int only_one_char(char *buf, int len, char c)
  {
      int i, ret;
  
      ret = 1;
      for (i=0; i<len; i++) {
          if (buf[i] != c) {
              ret = 0;
              break;
          }
      }
      return ret;
  }
  
  int partition_wiped(char *source)
  {
      char buf[4096];
      int fd, ret, wiped;
  
      if ((fd = open(source, O_RDONLY)) < 0) {
          return 0;
      }
  
      ret = read(fd, buf, sizeof(buf));
      close(fd);
  
      if (ret != sizeof(buf)) {
          return 0;
      }
  
      /* Check for all zeros */
      if (only_one_char(buf, sizeof(buf), 0)) {
         return 1;
      }
  
      /* Check for all ones */
      if (only_one_char(buf, sizeof(buf), 0xff)) {
         return 1;
      }
  
      return 0;
  }
  
  