master
1/* $NetBSD: disklabel.h,v 1.127 2022/11/01 06:47:41 simonb Exp $ */
2
3/*
4 * Copyright (c) 1987, 1988, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)disklabel.h 8.2 (Berkeley) 7/10/94
32 */
33
34#ifndef _SYS_DISKLABEL_H_
35#define _SYS_DISKLABEL_H_
36
37/*
38 * We need <machine/types.h> for __HAVE_OLD_DISKLABEL
39 */
40#ifndef _LOCORE
41#include <sys/types.h>
42#endif
43
44/*
45 * Each disk has a label which includes information about the hardware
46 * disk geometry, filesystem partitions, and drive specific information.
47 * The location of the label, as well as the number of partitions the
48 * label can describe and the number of the "whole disk" (raw)
49 * partition are machine dependent.
50 */
51#if HAVE_NBTOOL_CONFIG_H
52#undef MAXPARTITIONS
53#define MAXPARTITIONS MAXMAXPARTITIONS
54#else
55#include <machine/disklabel.h>
56#endif /* HAVE_NBTOOL_CONFIG_H */
57
58/*
59 * The absolute maximum number of disk partitions allowed.
60 * This is the maximum value of MAXPARTITIONS for which 'struct disklabel'
61 * is <= DEV_BSIZE bytes long. If MAXPARTITIONS is greater than this, beware.
62 */
63#define MAXMAXPARTITIONS 22
64#if MAXPARTITIONS > MAXMAXPARTITIONS
65#warning beware: MAXPARTITIONS bigger than MAXMAXPARTITIONS
66#endif
67
68/*
69 * Ports can switch their MAXPARTITIONS once, as follows:
70 *
71 * - define OLDMAXPARTITIONS in <machine/disklabel.h> as the old number
72 * - define MAXPARTITIONS as the new number
73 * - define DISKUNIT, DISKPART and DISKMINOR macros in <machine/disklabel.h>
74 * as appropriate for the port (see the i386 one for an example).
75 * - define __HAVE_OLD_DISKLABEL in <machine/types.h>
76 */
77
78#if defined(_KERNEL) && defined(__HAVE_OLD_DISKLABEL) && \
79 (MAXPARTITIONS < OLDMAXPARTITIONS)
80#error "can only grow disklabel size"
81#endif
82
83
84/*
85 * Translate between device numbers and major/disk unit/disk partition.
86 */
87#ifndef __HAVE_OLD_DISKLABEL
88#if !HAVE_NBTOOL_CONFIG_H
89#define DISKUNIT(dev) (minor(dev) / MAXPARTITIONS)
90#define DISKPART(dev) (minor(dev) % MAXPARTITIONS)
91#define DISKMINOR(unit, part) \
92 (((unit) * MAXPARTITIONS) + (part))
93#endif /* !HAVE_NBTOOL_CONFIG_H */
94#endif
95#define MAKEDISKDEV(maj, unit, part) \
96 (makedev((maj), DISKMINOR((unit), (part))))
97
98#define DISKMAGIC ((uint32_t)0x82564557) /* The disk magic number */
99
100#ifndef _LOCORE
101struct partition { /* the partition table */
102 uint32_t p_size; /* number of sectors in partition */
103 uint32_t p_offset; /* starting sector */
104 union {
105 uint32_t fsize; /* FFS, ADOS: filesystem basic fragment size */
106 uint32_t cdsession; /* ISO9660: session offset */
107 } __partition_u2;
108#define p_fsize __partition_u2.fsize
109#define p_cdsession __partition_u2.cdsession
110 uint8_t p_fstype; /* filesystem type, see below */
111 uint8_t p_frag; /* filesystem fragments per block */
112 union {
113 uint16_t cpg; /* UFS: FS cylinders per group */
114 uint16_t sgs; /* LFS: FS segment shift */
115 } __partition_u1;
116#define p_cpg __partition_u1.cpg
117#define p_sgs __partition_u1.sgs
118};
119
120/*
121 * We'd rather have disklabel be the same size on 32 and 64 bit systems
122 * but it really isn't. In revision 108 matt@ tried to do that by adding
123 * un_d_pad as a uint64_t. This was really smart because the net effect
124 * was to grow the struct by 4 bytes on most LP32 machines and make it
125 * the same as LP64 without changing the layout (which is a nono because
126 * it is stored on existing disks). The easy way would have been to add
127 * padding at the end, but that would have been confusing (although that
128 * is what actually happens), because the partitions structure is supposed
129 * to be variable size and putting a padding uint32_t would be weird.
130 * Unfornately mips32 and i386 align uint64_t standalone at an 8 byte
131 * boundary, but in structures at a 4 byte boundary so matt's
132 * change did not affect them.
133 *
134 * We also prefer to have the structure 4 byte aligned so that the
135 * subr_disk_mbr.c code that scans for label does not trigger ubsan
136 * when comparing magic (without making the code ugly). To do this
137 * we can unexpose the d_boot{0,1} pointers in the kernel (so that
138 * LP64 systems can become 4 byte aligned) and at the same time
139 * remove the un_d_pad member and add padding at the end. The d_boot{0,1}
140 * fields are only used in userland in getdiskbyname(3), filled with
141 * the names of the primary and secondary bootstrap from /etc/disktab.
142 *
143 * While this is a way forward, it is not clear that it is the best
144 * way forward. The ubsan warning is incorrect and the code
145 * will always work since d_magic is always 4 byte aligned even
146 * when structure disklabel is not 8 byte aligned, so what we do
147 * now is ignore it. Another way would be to do offset arithmetic
148 * on the pointer and use it as a char *. That would not prevent
149 * other misaligned accesses in the future. Finally one could
150 * copy the unaligned structure to an aligned one, but that eats
151 * up space on the stack.
152 */
153struct disklabel {
154 uint32_t d_magic; /* the magic number */
155 uint16_t d_type; /* drive type */
156 uint16_t d_subtype; /* controller/d_type specific */
157 char d_typename[16]; /* type name, e.g. "eagle" */
158
159 /*
160 * d_packname contains the pack identifier and is returned when
161 * the disklabel is read off the disk or in-core copy.
162 * d_boot0 and d_boot1 are the (optional) names of the
163 * primary (block 0) and secondary (block 1-15) bootstraps
164 * as found in /usr/mdec. These are returned when using
165 * getdiskbyname(3) to retrieve the values from /etc/disktab.
166 */
167 union {
168 char un_d_packname[16]; /* pack identifier */
169 struct {
170 char *un_d_boot0; /* primary bootstrap name */
171 char *un_d_boot1; /* secondary bootstrap name */
172 } un_b;
173 uint64_t un_d_pad; /* force 8 byte alignment */
174 } d_un;
175#define d_packname d_un.un_d_packname
176#define d_boot0 d_un.un_b.un_d_boot0
177#define d_boot1 d_un.un_b.un_d_boot1
178
179 /* disk geometry: */
180 uint32_t d_secsize; /* # of bytes per sector */
181 uint32_t d_nsectors; /* # of data sectors per track */
182 uint32_t d_ntracks; /* # of tracks per cylinder */
183 uint32_t d_ncylinders; /* # of data cylinders per unit */
184 uint32_t d_secpercyl; /* # of data sectors per cylinder */
185 uint32_t d_secperunit; /* # of data sectors per unit */
186
187 /*
188 * Spares (bad sector replacements) below are not counted in
189 * d_nsectors or d_secpercyl. Spare sectors are assumed to
190 * be physical sectors which occupy space at the end of each
191 * track and/or cylinder.
192 */
193 uint16_t d_sparespertrack; /* # of spare sectors per track */
194 uint16_t d_sparespercyl; /* # of spare sectors per cylinder */
195 /*
196 * Alternative cylinders include maintenance, replacement,
197 * configuration description areas, etc.
198 */
199 uint32_t d_acylinders; /* # of alt. cylinders per unit */
200
201 /* hardware characteristics: */
202 /*
203 * d_interleave, d_trackskew and d_cylskew describe perturbations
204 * in the media format used to compensate for a slow controller.
205 * Interleave is physical sector interleave, set up by the
206 * formatter or controller when formatting. When interleaving is
207 * in use, logically adjacent sectors are not physically
208 * contiguous, but instead are separated by some number of
209 * sectors. It is specified as the ratio of physical sectors
210 * traversed per logical sector. Thus an interleave of 1:1
211 * implies contiguous layout, while 2:1 implies that logical
212 * sector 0 is separated by one sector from logical sector 1.
213 * d_trackskew is the offset of sector 0 on track N relative to
214 * sector 0 on track N-1 on the same cylinder. Finally, d_cylskew
215 * is the offset of sector 0 on cylinder N relative to sector 0
216 * on cylinder N-1.
217 */
218 uint16_t d_rpm; /* rotational speed */
219 uint16_t d_interleave; /* hardware sector interleave */
220 uint16_t d_trackskew; /* sector 0 skew, per track */
221 uint16_t d_cylskew; /* sector 0 skew, per cylinder */
222 uint32_t d_headswitch; /* head switch time, usec */
223 uint32_t d_trkseek; /* track-to-track seek, usec */
224 uint32_t d_flags; /* generic flags */
225#define NDDATA 5
226 uint32_t d_drivedata[NDDATA]; /* drive-type specific information */
227#define NSPARE 5
228 uint32_t d_spare[NSPARE]; /* reserved for future use */
229 uint32_t d_magic2; /* the magic number (again) */
230 uint16_t d_checksum; /* xor of data incl. partitions */
231
232 /* filesystem and partition information: */
233 uint16_t d_npartitions; /* number of partitions in following */
234 uint32_t d_bbsize; /* size of boot area at sn0, bytes */
235 uint32_t d_sbsize; /* max size of fs superblock, bytes */
236 struct partition d_partitions[MAXPARTITIONS];
237 /* the partition table, actually may be more */
238};
239
240#if defined(__HAVE_OLD_DISKLABEL) && !HAVE_NBTOOL_CONFIG_H
241/*
242 * Same as above, but with OLDMAXPARTITIONS partitions. For use in
243 * the old DIOC* ioctl calls.
244 */
245struct olddisklabel {
246 uint32_t d_magic;
247 uint16_t d_type;
248 uint16_t d_subtype;
249 char d_typename[16];
250 union {
251 char un_d_packname[16];
252 struct {
253 char *un_d_boot0;
254 char *un_d_boot1;
255 } un_b;
256 } d_un;
257 uint32_t d_secsize;
258 uint32_t d_nsectors;
259 uint32_t d_ntracks;
260 uint32_t d_ncylinders;
261 uint32_t d_secpercyl;
262 uint32_t d_secperunit;
263 uint16_t d_sparespertrack;
264 uint16_t d_sparespercyl;
265 uint32_t d_acylinders;
266 uint16_t d_rpm;
267 uint16_t d_interleave;
268 uint16_t d_trackskew;
269 uint16_t d_cylskew;
270 uint32_t d_headswitch;
271 uint32_t d_trkseek;
272 uint32_t d_flags;
273 uint32_t d_drivedata[NDDATA];
274 uint32_t d_spare[NSPARE];
275 uint32_t d_magic2;
276 uint16_t d_checksum;
277 uint16_t d_npartitions;
278 uint32_t d_bbsize;
279 uint32_t d_sbsize;
280 struct opartition {
281 uint32_t p_size;
282 uint32_t p_offset;
283 union {
284 uint32_t fsize;
285 uint32_t cdsession;
286 } __partition_u2;
287 uint8_t p_fstype;
288 uint8_t p_frag;
289 union {
290 uint16_t cpg;
291 uint16_t sgs;
292 } __partition_u1;
293 } d_partitions[OLDMAXPARTITIONS];
294};
295#endif /* __HAVE_OLD_DISKLABEL */
296#else /* _LOCORE */
297 /*
298 * offsets for asm boot files.
299 */
300 .set d_secsize,40
301 .set d_nsectors,44
302 .set d_ntracks,48
303 .set d_ncylinders,52
304 .set d_secpercyl,56
305 .set d_secperunit,60
306 .set d_end_,148+(MAXPARTITIONS*16)
307#endif /* _LOCORE */
308
309/*
310 * We normally use C99 initialisers (just in case the lists below are out
311 * of sequence, or have gaps), but lint doesn't grok them.
312 * Maybe some host compilers don't either, but many have for quite some time.
313 */
314
315#ifndef lint
316#define ARRAY_INIT(element,value) [element]=value
317#else
318#define ARRAY_INIT(element,value) value
319#endif
320
321/* Use pre-processor magic to get all the parameters one one line... */
322
323/* d_type values: */
324#define DKTYPE_DEFN(x) \
325x(UNKNOWN, 0, "unknown") \
326x(SMD, 1, "SMD") /* SMD, XSMD; VAX hp/up */ \
327x(MSCP, 2, "MSCP") /* MSCP */ \
328x(DEC, 3, "old DEC") /* other DEC (rk, rl) */ \
329x(SCSI, 4, "SCSI") /* SCSI */ \
330x(ESDI, 5, "ESDI") /* ESDI interface */ \
331x(ST506, 6, "ST506") /* ST506 etc. */ \
332x(HPIB, 7, "HP-IB") /* CS/80 on HP-IB */ \
333x(HPFL, 8, "HP-FL") /* HP Fiber-link */ \
334x(TYPE_9, 9, "type 9") \
335x(FLOPPY, 10, "floppy") /* floppy */ \
336x(CCD, 11, "ccd") /* concatenated disk device */ \
337x(VND, 12, "vnd") /* uvnode pseudo-disk */ \
338x(ATAPI, 13, "ATAPI") /* ATAPI */ \
339x(RAID, 14, "RAID") /* RAIDframe */ \
340x(LD, 15, "ld") /* logical disk */ \
341x(JFS2, 16, "jfs") /* IBM JFS2 */ \
342x(CGD, 17, "cgd") /* cryptographic pseudo-disk */ \
343x(VINUM, 18, "vinum") /* vinum volume */ \
344x(FLASH, 19, "flash") /* flash memory devices */ \
345x(DM, 20, "dm") /* device-mapper pseudo-disk devices */\
346x(RUMPD, 21, "rumpd") /* rump virtual disk */ \
347x(MD, 22, "md") /* memory disk */ \
348
349#ifndef _LOCORE
350#define DKTYPE_NUMS(tag, number, name) __CONCAT(DKTYPE_,tag=number),
351#ifndef DKTYPE_ENUMNAME
352#define DKTYPE_ENUMNAME
353#endif
354enum DKTYPE_ENUMNAME { DKTYPE_DEFN(DKTYPE_NUMS) DKMAXTYPES };
355#undef DKTYPE_NUMS
356#endif
357
358#ifdef DKTYPENAMES
359#define DKTYPE_NAMES(tag, number, name) ARRAY_INIT(number,name),
360static const char *const dktypenames[] = { DKTYPE_DEFN(DKTYPE_NAMES) NULL };
361#undef DKTYPE_NAMES
362#endif
363
364/*
365 * Partition type names, numbers, label-names, fsck prog, and mount prog
366 */
367#define FSTYPE_DEFN(x) \
368x(UNUSED, 0, "unused", NULL, NULL) /* unused */ \
369x(SWAP, 1, "swap", NULL, NULL) /* swap */ \
370x(V6, 2, "Version 6", NULL, NULL) /* Sixth Edition */ \
371x(V7, 3, "Version 7", "v7fs", "v7fs") /* Seventh Edition */ \
372x(SYSV, 4, "System V", NULL, NULL) /* System V */ \
373x(V71K, 5, "4.1BSD", NULL, NULL) /* V7, 1K blocks (4.1, 2.9) */ \
374x(V8, 6, "Eighth Edition",NULL, NULL) /* Eighth Edition, 4K blocks */ \
375x(BSDFFS, 7, "4.2BSD", "ffs", "ffs") /* 4.2BSD fast file system */ \
376x(MSDOS, 8, "MSDOS", "msdos", "msdos") /* MSDOS file system */ \
377x(BSDLFS, 9, "4.4LFS", "lfs", "lfs") /* 4.4BSD log-structured FS */ \
378x(OTHER, 10, "unknown", NULL, NULL) /* in use, unknown/unsupported */\
379x(HPFS, 11, "HPFS", NULL, NULL) /* OS/2 high-performance FS */ \
380x(ISO9660, 12, "ISO9660", NULL, "cd9660")/* ISO 9660, normally CD-ROM */ \
381x(BOOT, 13, "boot", NULL, NULL) /* bootstrap code in partition */\
382x(ADOS, 14, "ADOS", NULL, "ados") /* AmigaDOS fast file system */ \
383x(HFS, 15, "HFS", NULL, NULL) /* Macintosh HFS */ \
384x(FILECORE,16, "FILECORE", NULL, "filecore")/* Acorn Filecore FS */ \
385x(EX2FS, 17, "Linux Ext2","ext2fs","ext2fs")/* Linux Extended 2 FS */ \
386x(NTFS, 18, "NTFS", NULL, "ntfs") /* Windows/NT file system */ \
387x(RAID, 19, "RAID", NULL, NULL) /* RAIDframe component */ \
388x(CCD, 20, "ccd", NULL, NULL) /* concatenated disk component */\
389x(JFS2, 21, "jfs", NULL, NULL) /* IBM JFS2 */ \
390x(APPLEUFS,22, "Apple UFS", "ffs", "ffs") /* Apple UFS */ \
391/* XXX this is not the same as FreeBSD. How to solve? */ \
392x(VINUM, 23, "vinum", NULL, NULL) /* Vinum */ \
393x(UDF, 24, "UDF", NULL, "udf") /* UDF */ \
394x(SYSVBFS, 25, "SysVBFS", NULL, "sysvbfs")/* System V boot file system */ \
395x(EFS, 26, "EFS", NULL, "efs") /* SGI's Extent Filesystem */ \
396x(NILFS, 27, "NiLFS", NULL, "nilfs") /* NTT's NiLFS(2) */ \
397x(CGD, 28, "cgd", NULL, NULL) /* Cryptographic disk */ \
398x(MINIXFS3,29, "MINIX FSv3", NULL, NULL) /* MINIX file system v3 */ \
399x(VMKCORE, 30, "VMware vmkcore", NULL, NULL) /* VMware vmkcore */ \
400x(VMFS, 31, "VMware VMFS", NULL, NULL) /* VMware VMFS */ \
401x(VMWRESV, 32, "VMware Reserved", NULL, NULL) /* VMware reserved */ \
402x(ZFS, 33, "ZFS", NULL, "zfs") /* ZFS */
403
404
405#ifndef _LOCORE
406#define FS_TYPENUMS(tag, number, name, fsck, mount) __CONCAT(FS_,tag=number),
407#ifndef FSTYPE_ENUMNAME
408#define FSTYPE_ENUMNAME
409#endif
410enum FSTYPE_ENUMNAME { FSTYPE_DEFN(FS_TYPENUMS) FSMAXTYPES };
411#undef FS_TYPENUMS
412#endif
413
414#ifdef FSTYPENAMES
415#define FS_TYPENAMES(tag, number, name, fsck, mount) ARRAY_INIT(number,name),
416static const char *const fstypenames[] = { FSTYPE_DEFN(FS_TYPENAMES) NULL };
417#undef FS_TYPENAMES
418#endif
419
420#ifdef FSCKNAMES
421/* These are the names MOUNT_XXX from <sys/mount.h> */
422#define FS_FSCKNAMES(tag, number, name, fsck, mount) ARRAY_INIT(number,fsck),
423static const char *const fscknames[] = { FSTYPE_DEFN(FS_FSCKNAMES) NULL };
424#undef FS_FSCKNAMES
425#define FSMAXNAMES FSMAXTYPES
426#endif
427
428#ifdef MOUNTNAMES
429/* These are the names MOUNT_XXX from <sys/mount.h> */
430#define FS_MOUNTNAMES(tag, number, name, fsck, mount) ARRAY_INIT(number,mount),
431static const char *const mountnames[] = { FSTYPE_DEFN(FS_MOUNTNAMES) NULL };
432#undef FS_MOUNTNAMES
433#define FSMAXMOUNTNAMES FSMAXTYPES
434#endif
435
436/*
437 * flags shared by various drives:
438 */
439#define D_REMOVABLE 0x01 /* removable media */
440#define D_ECC 0x02 /* supports ECC */
441#define D_BADSECT 0x04 /* supports bad sector forw. */
442#define D_RAMDISK 0x08 /* disk emulator */
443#define D_CHAIN 0x10 /* can do back-back transfers */
444#define D_SCSI_MMC 0x20 /* SCSI MMC sessioned media */
445
446/*
447 * Drive data for SMD.
448 */
449#define d_smdflags d_drivedata[0]
450#define D_SSE 0x1 /* supports skip sectoring */
451#define d_mindist d_drivedata[1]
452#define d_maxdist d_drivedata[2]
453#define d_sdist d_drivedata[3]
454
455/*
456 * Drive data for ST506.
457 */
458#define d_precompcyl d_drivedata[0]
459#define d_gap3 d_drivedata[1] /* used only when formatting */
460
461/*
462 * Drive data for SCSI.
463 */
464#define d_blind d_drivedata[0]
465
466#ifndef _LOCORE
467/*
468 * Structure used to perform a format or other raw operation,
469 * returning data and/or register values. Register identification
470 * and format are device- and driver-dependent. Currently unused.
471 */
472struct format_op {
473 char *df_buf;
474 int df_count; /* value-result */
475 daddr_t df_startblk;
476 int df_reg[8]; /* result */
477};
478
479#ifdef _KERNEL
480/*
481 * Structure used internally to retrieve information about a partition
482 * on a disk.
483 */
484struct partinfo {
485 uint64_t pi_offset;
486 uint64_t pi_size;
487 uint32_t pi_secsize;
488 uint32_t pi_bsize;
489 uint8_t pi_fstype;
490 uint8_t pi_frag;
491 uint16_t pi_cpg;
492 uint32_t pi_fsize;
493};
494
495struct disk;
496
497int disk_read_sectors(void (*)(struct buf *), const struct disklabel *,
498 struct buf *, unsigned int, int);
499void diskerr(const struct buf *, const char *, const char *, int,
500 int, const struct disklabel *);
501int setdisklabel(struct disklabel *, struct disklabel *, u_long,
502 struct cpu_disklabel *);
503const char *readdisklabel(dev_t, void (*)(struct buf *),
504 struct disklabel *, struct cpu_disklabel *);
505int writedisklabel(dev_t, void (*)(struct buf *), struct disklabel *,
506 struct cpu_disklabel *);
507const char *convertdisklabel(struct disklabel *, void (*)(struct buf *),
508 struct buf *, uint32_t);
509int bounds_check_with_label(struct disk *, struct buf *, int);
510int bounds_check_with_mediasize(struct buf *, int, uint64_t);
511const char *getfstypename(int);
512int disklabel_dev_unit(dev_t);
513#endif
514#endif /* _LOCORE */
515
516#if !defined(_KERNEL) && !defined(_LOCORE)
517
518#include <sys/cdefs.h>
519
520#endif
521
522#endif /* !_SYS_DISKLABEL_H_ */