genhd.h

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

#ifndef _LINUX_GENHD_H
#define _LINUX_GENHD_H

/*
 * 	genhd.h Copyright (C) 1992 Drew Eckhardt
 *	Generic hard disk header file by  
 * 		Drew Eckhardt
 *
 *		<[e-mail]>
 */

#include <linux/config.h>

#define CONFIG_MSDOS_PARTITION 1

#ifdef __alpha__
#define CONFIG_OSF_PARTITION 1
#endif

#if defined(__sparc__) || defined(CONFIG_SMD_DISKLABEL)
#define CONFIG_SUN_PARTITION 1
#endif

/* These three have identical behaviour; use the second one if DOS fdisk gets
   confused about extended/logical partitions starting past cylinder 1023. */
#define DOS_EXTENDED_PARTITION 5
#define LINUX_EXTENDED_PARTITION 0x85
#define WIN98_EXTENDED_PARTITION 0x0f

#define DM6_PARTITION		0x54	/* has DDO: use xlated geom & offset */
#define EZD_PARTITION		0x55	/* EZ-DRIVE:  same as DM6 (we think) */
#define DM6_AUX1PARTITION	0x51	/* no DDO:  use xlated geom */
#define DM6_AUX3PARTITION	0x53	/* no DDO:  use xlated geom */
	
struct partition {
	unsigned char boot_ind;		/* 0x80 - active */
	unsigned char head;		/* starting head */
	unsigned char sector;		/* starting sector */
	unsigned char cyl;		/* starting cylinder */
	unsigned char sys_ind;		/* What partition type */
	unsigned char end_head;		/* end head */
	unsigned char end_sector;	/* end sector */
	unsigned char end_cyl;		/* end cylinder */
	unsigned int start_sect;	/* starting sector counting from 0 */
	unsigned int nr_sects;		/* nr of sectors in partition */
} __attribute((packed));	/* Give a polite hint to egcs/alpha to generate
				   unaligned operations */

struct hd_struct {
	long start_sect;
	long nr_sects;
};

struct gendisk {
	int major;			/* major number of driver */
	const char *major_name;		/* name of major driver */
	int minor_shift;		/* number of times minor is shifted to
					   get real minor */
	int max_p;			/* maximum partitions per device */
	int max_nr;			/* maximum number of real devices */

	void (*init)(struct gendisk *);	/* Initialization called before we do our thing */
	struct hd_struct *part;		/* partition table */
	int *sizes;			/* device size in blocks, copied to blk_size[] */
	int nr_real;			/* number of real devices */

	void *real_devices;		/* internal use */
	struct gendisk *next;
};

#ifdef CONFIG_BSD_DISKLABEL
/*
 * BSD disklabel support by Yossi Gottlieb <[e-mail]>
 */

#define BSD_PARTITION		0xa5	/* Partition ID */

#define BSD_DISKMAGIC	(0x82564557UL)	/* The disk magic number */
#define BSD_MAXPARTITIONS	8
#define BSD_FS_UNUSED		0	/* disklabel unused partition entry ID */
struct bsd_disklabel {
	__u32	d_magic;		/* the magic number */
	__s16	d_type;			/* drive type */
	__s16	d_subtype;		/* controller/d_type specific */
	char	d_typename[16];		/* type name, e.g. "eagle" */
	char	d_packname[16];			/* pack identifier */ 
	__u32	d_secsize;		/* # of bytes per sector */
	__u32	d_nsectors;		/* # of data sectors per track */
	__u32	d_ntracks;		/* # of tracks per cylinder */
	__u32	d_ncylinders;		/* # of data cylinders per unit */
	__u32	d_secpercyl;		/* # of data sectors per cylinder */
	__u32	d_secperunit;		/* # of data sectors per unit */
	__u16	d_sparespertrack;	/* # of spare sectors per track */
	__u16	d_sparespercyl;		/* # of spare sectors per cylinder */
	__u32	d_acylinders;		/* # of alt. cylinders per unit */
	__u16	d_rpm;			/* rotational speed */
	__u16	d_interleave;		/* hardware sector interleave */
	__u16	d_trackskew;		/* sector 0 skew, per track */
	__u16	d_cylskew;		/* sector 0 skew, per cylinder */
	__u32	d_headswitch;		/* head switch time, usec */
	__u32	d_trkseek;		/* track-to-track seek, usec */
	__u32	d_flags;		/* generic flags */
#define NDDATA 5
	__u32	d_drivedata[NDDATA];	/* drive-type specific information */
#define NSPARE 5
	__u32	d_spare[NSPARE];	/* reserved for future use */
	__u32	d_magic2;		/* the magic number (again) */
	__u16	d_checksum;		/* xor of data incl. partitions */

			/* filesystem and partition information: */
	__u16	d_npartitions;		/* number of partitions in following */
	__u32	d_bbsize;		/* size of boot area at sn0, bytes */
	__u32	d_sbsize;		/* max size of fs superblock, bytes */
	struct	bsd_partition {		/* the partition table */
		__u32	p_size;		/* number of sectors in partition */
		__u32	p_offset;	/* starting sector */
		__u32	p_fsize;	/* filesystem basic fragment size */
		__u8	p_fstype;	/* filesystem type, see below */
		__u8	p_frag;		/* filesystem fragments per block */
		__u16	p_cpg;		/* filesystem cylinders per group */
	} d_partitions[BSD_MAXPARTITIONS];	/* actually may be more */
};

#endif	/* CONFIG_BSD_DISKLABEL */

extern struct gendisk *gendisk_head;	/* linked list of disks */

/*
 * disk_name() is used by genhd.c and md.c.
 * It formats the devicename of the indicated disk
 * into the supplied buffer, and returns a pointer
 * to that same buffer (for convenience).
 */
char *disk_name (struct gendisk *hd, int minor, char *buf);

#endif