LXR linux/include/linux/adfs

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ADFS_FS_H
   3#define _ADFS_FS_H
   4
   5#include <uapi/linux/adfs_fs.h>
   6
   7/*
   8 * Calculate the boot block checksum on an ADFS drive.  Note that this will
   9 * appear to be correct if the sector contains all zeros, so also check that
  10 * the disk size is non-zero!!!
  11 */
  12static inline int adfs_checkbblk(unsigned char *ptr)
  13{
  14        unsigned int result = 0;
  15        unsigned char *p = ptr + 511;
  16
  17        do {
  18                result = (result & 0xff) + (result >> 8);
  19                result = result + *--p;
  20        } while (p != ptr);
  21
  22        return (result & 0xff) != ptr[511];
  23}
  24#endif
  25