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 2009 Sun Microsystems, Inc.  All rights reserved.
20  * Use is subject to license terms.
21  */
22 
23 #ifndef	_SYS_ZAP_IMPL_H
24 #define	_SYS_ZAP_IMPL_H
25 
26 #define	ZAP_MAGIC 0x2F52AB2ABULL
27 
28 #define	MZAP_ENT_LEN		64
29 #define	MZAP_NAME_LEN		(MZAP_ENT_LEN - 8 - 4 - 2)
30 #define	MZAP_MAX_BLKSHIFT	SPA_MAXBLOCKSHIFT
31 #define	MZAP_MAX_BLKSZ		(1 << MZAP_MAX_BLKSHIFT)
32 
33 typedef struct mzap_ent_phys {
34 	uint64_t mze_value;
35 	uint32_t mze_cd;
36 	uint16_t mze_pad;	/* in case we want to chain them someday */
37 	char mze_name[MZAP_NAME_LEN];
38 } mzap_ent_phys_t;
39 
40 typedef struct mzap_phys {
41 	uint64_t mz_block_type;	/* ZBT_MICRO */
42 	uint64_t mz_salt;
43 	uint64_t mz_pad[6];
44 	mzap_ent_phys_t mz_chunk[1];
45 	/* actually variable size depending on block size */
46 } mzap_phys_t;
47 
48 /*
49  * The (fat) zap is stored in one object. It is an array of
50  * 1<<FZAP_BLOCK_SHIFT byte blocks. The layout looks like one of:
51  *
52  * ptrtbl fits in first block:
53  * 	[zap_phys_t zap_ptrtbl_shift < 6] [zap_leaf_t] ...
54  *
55  * ptrtbl too big for first block:
56  * 	[zap_phys_t zap_ptrtbl_shift >= 6] [zap_leaf_t] [ptrtbl] ...
57  *
58  */
59 
60 #define	ZBT_LEAF		((1ULL << 63) + 0)
61 #define	ZBT_HEADER		((1ULL << 63) + 1)
62 #define	ZBT_MICRO		((1ULL << 63) + 3)
63 /* any other values are ptrtbl blocks */
64 
65 /*
66  * the embedded pointer table takes up half a block:
67  * block size / entry size (2^3) / 2
68  */
69 #define	ZAP_EMBEDDED_PTRTBL_SHIFT(zap) (FZAP_BLOCK_SHIFT(zap) - 3 - 1)
70 
71 /*
72  * The embedded pointer table starts half-way through the block.  Since
73  * the pointer table itself is half the block, it starts at (64-bit)
74  * word number (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap)).
75  */
76 #define	ZAP_EMBEDDED_PTRTBL_ENT(zap, idx) \
77 	((uint64_t *)(zap)->zap_f.zap_phys) \
78 	[(idx) + (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap))]
79 
80 /*
81  * TAKE NOTE:
82  * If zap_phys_t is modified, zap_byteswap() must be modified.
83  */
84 typedef struct zap_phys {
85 	uint64_t zap_block_type;	/* ZBT_HEADER */
86 	uint64_t zap_magic;		/* ZAP_MAGIC */
87 
88 	struct zap_table_phys {
89 		uint64_t zt_blk;	/* starting block number */
90 		uint64_t zt_numblks;	/* number of blocks */
91 		uint64_t zt_shift;	/* bits to index it */
92 		uint64_t zt_nextblk;	/* next (larger) copy start block */
93 		uint64_t zt_blks_copied; /* number source blocks copied */
94 	} zap_ptrtbl;
95 
96 	uint64_t zap_freeblk;		/* the next free block */
97 	uint64_t zap_num_leafs;		/* number of leafs */
98 	uint64_t zap_num_entries;	/* number of entries */
99 	uint64_t zap_salt;		/* salt to stir into hash function */
100 	uint64_t zap_normflags;		/* flags for u8_textprep_str() */
101 	uint64_t zap_flags;		/* zap_flag_t */
102 	/*
103 	 * This structure is followed by padding, and then the embedded
104 	 * pointer table.  The embedded pointer table takes up second
105 	 * half of the block.  It is accessed using the
106 	 * ZAP_EMBEDDED_PTRTBL_ENT() macro.
107 	 */
108 } zap_phys_t;
109 
110 #endif /* _SYS_ZAP_IMPL_H */
111