swh:1:snp:c2847dfd741eae21606027cf29250d1ebcd63fb4
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Tip revision: a3b22b9f11d9fbc48b0291ea92259a5a810e9438 authored by Linus Torvalds on 18 February 2019, 02:46:40 UTC
Linux 5.0-rc7
Tip revision: a3b22b9
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
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