swh:1:snp:c2847dfd741eae21606027cf29250d1ebcd63fb4
Raw File
Tip revision: a99d8080aaf358d5d23581244e5da23b35e340b9 authored by Linus Torvalds on 03 November 2019, 22:07:26 UTC
Linux 5.4-rc6
Tip revision: a99d808
adfs_fs.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ADFS_FS_H
#define _ADFS_FS_H

#include <uapi/linux/adfs_fs.h>

/*
 * Calculate the boot block checksum on an ADFS drive.  Note that this will
 * appear to be correct if the sector contains all zeros, so also check that
 * the disk size is non-zero!!!
 */
static inline int adfs_checkbblk(unsigned char *ptr)
{
	unsigned int result = 0;
	unsigned char *p = ptr + 511;

	do {
	        result = (result & 0xff) + (result >> 8);
        	result = result + *--p;
	} while (p != ptr);

	return (result & 0xff) != ptr[511];
}
#endif
back to top