linux_old1/include/linux/adfs_fs.h

64 lines
1.3 KiB
C
Raw Normal View History

#ifndef _ADFS_FS_H
#define _ADFS_FS_H
#include <linux/types.h>
#include <linux/magic.h>
/*
* Disc Record at disc address 0xc00
*/
struct adfs_discrecord {
__u8 log2secsize;
__u8 secspertrack;
__u8 heads;
__u8 density;
__u8 idlen;
__u8 log2bpmb;
__u8 skew;
__u8 bootoption;
__u8 lowsector;
__u8 nzones;
__le16 zone_spare;
__le32 root;
__le32 disc_size;
__le16 disc_id;
__u8 disc_name[10];
__le32 disc_type;
__le32 disc_size_high;
__u8 log2sharesize:4;
__u8 unused40:4;
__u8 big_flag:1;
__u8 unused41:1;
__u8 nzones_high;
__le32 format_version;
__le32 root_size;
__u8 unused52[60 - 52];
};
#define ADFS_DISCRECORD (0xc00)
#define ADFS_DR_OFFSET (0x1c0)
#define ADFS_DR_SIZE 60
#define ADFS_DR_SIZE_BITS (ADFS_DR_SIZE << 3)
#ifdef __KERNEL__
/*
* 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
#endif