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