1 /*
2  *  GRUB  --  GRand Unified Bootloader
3  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
4  *
5  *  This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation; either version 2 of the License, or
8  *  (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *  GNU General Public License for more details.
14  *
15  *  You should have received a copy of the GNU General Public License
16  *  along with this program; If not, see <http://www.gnu.org/licenses/>.
17  */
18 /*
19  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
20  * Use is subject to license terms.
21  */
22 
23 #ifndef	_SYS_ZAP_LEAF_H
24 #define	_SYS_ZAP_LEAF_H
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #define	ZAP_LEAF_MAGIC 0x2AB1EAF
29 
30 /* chunk size = 24 bytes */
31 #define	ZAP_LEAF_CHUNKSIZE 24
32 
33 /*
34  * The amount of space within the chunk available for the array is:
35  * chunk size - space for type (1) - space for next pointer (2)
36  */
37 #define	ZAP_LEAF_ARRAY_BYTES (ZAP_LEAF_CHUNKSIZE - 3)
38 
39 typedef enum zap_chunk_type {
40 	ZAP_CHUNK_FREE = 253,
41 	ZAP_CHUNK_ENTRY = 252,
42 	ZAP_CHUNK_ARRAY = 251,
43 	ZAP_CHUNK_TYPE_MAX = 250
44 } zap_chunk_type_t;
45 
46 /*
47  * TAKE NOTE:
48  * If zap_leaf_phys_t is modified, zap_leaf_byteswap() must be modified.
49  */
50 typedef struct zap_leaf_phys {
51 	struct zap_leaf_header {
52 		uint64_t lh_block_type;		/* ZBT_LEAF */
53 		uint64_t lh_pad1;
54 		uint64_t lh_prefix;		/* hash prefix of this leaf */
55 		uint32_t lh_magic;		/* ZAP_LEAF_MAGIC */
56 		uint16_t lh_nfree;		/* number free chunks */
57 		uint16_t lh_nentries;		/* number of entries */
58 		uint16_t lh_prefix_len;		/* num bits used to id this */
59 
60 /* above is accessable to zap, below is zap_leaf private */
61 
62 		uint16_t lh_freelist;		/* chunk head of free list */
63 		uint8_t lh_pad2[12];
64 	} l_hdr; /* 2 24-byte chunks */
65 
66 	/*
67 	 * The header is followed by a hash table with
68 	 * ZAP_LEAF_HASH_NUMENTRIES(zap) entries.  The hash table is
69 	 * followed by an array of ZAP_LEAF_NUMCHUNKS(zap)
70 	 * zap_leaf_chunk structures.  These structures are accessed
71 	 * with the ZAP_LEAF_CHUNK() macro.
72 	 */
73 
74 	uint16_t l_hash[1];
75 } zap_leaf_phys_t;
76 
77 typedef union zap_leaf_chunk {
78 	struct zap_leaf_entry {
79 		uint8_t le_type; 		/* always ZAP_CHUNK_ENTRY */
80 		uint8_t le_int_size;		/* size of ints */
81 		uint16_t le_next;		/* next entry in hash chain */
82 		uint16_t le_name_chunk;		/* first chunk of the name */
83 		uint16_t le_name_length;	/* bytes in name, incl null */
84 		uint16_t le_value_chunk;	/* first chunk of the value */
85 		uint16_t le_value_length;	/* value length in ints */
86 		uint32_t le_cd;			/* collision differentiator */
87 		uint64_t le_hash;		/* hash value of the name */
88 	} l_entry;
89 	struct zap_leaf_array {
90 		uint8_t la_type;		/* always ZAP_CHUNK_ARRAY */
91 		uint8_t la_array[ZAP_LEAF_ARRAY_BYTES];
92 		uint16_t la_next;		/* next blk or CHAIN_END */
93 	} l_array;
94 	struct zap_leaf_free {
95 		uint8_t lf_type;		/* always ZAP_CHUNK_FREE */
96 		uint8_t lf_pad[ZAP_LEAF_ARRAY_BYTES];
97 		uint16_t lf_next;	/* next in free list, or CHAIN_END */
98 	} l_free;
99 } zap_leaf_chunk_t;
100 
101 #endif /* _SYS_ZAP_LEAF_H */
102