1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */ 2*4882a593Smuzhiyun #ifndef _ADFS_FS_H 3*4882a593Smuzhiyun #define _ADFS_FS_H 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun #include <uapi/linux/adfs_fs.h> 6*4882a593Smuzhiyun 7*4882a593Smuzhiyun /* 8*4882a593Smuzhiyun * Calculate the boot block checksum on an ADFS drive. Note that this will 9*4882a593Smuzhiyun * appear to be correct if the sector contains all zeros, so also check that 10*4882a593Smuzhiyun * the disk size is non-zero!!! 11*4882a593Smuzhiyun */ adfs_checkbblk(unsigned char * ptr)12*4882a593Smuzhiyunstatic inline int adfs_checkbblk(unsigned char *ptr) 13*4882a593Smuzhiyun { 14*4882a593Smuzhiyun unsigned int result = 0; 15*4882a593Smuzhiyun unsigned char *p = ptr + 511; 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun do { 18*4882a593Smuzhiyun result = (result & 0xff) + (result >> 8); 19*4882a593Smuzhiyun result = result + *--p; 20*4882a593Smuzhiyun } while (p != ptr); 21*4882a593Smuzhiyun 22*4882a593Smuzhiyun return (result & 0xff) != ptr[511]; 23*4882a593Smuzhiyun } 24*4882a593Smuzhiyun #endif 25