/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef _SYS_ZAP_IMPL_H
#define _SYS_ZAP_IMPL_H

#define ZAP_MAGIC 0x2F52AB2ABULL

#define MZAP_ENT_LEN            64
#define MZAP_NAME_LEN           (MZAP_ENT_LEN - 8 - 4 - 2)
#define MZAP_MAX_BLKSHIFT       SPA_MAXBLOCKSHIFT
#define MZAP_MAX_BLKSZ          (1 << MZAP_MAX_BLKSHIFT)

typedef struct mzap_ent_phys {
        uint64_t mze_value;
        uint32_t mze_cd;
        uint16_t mze_pad;       /* in case we want to chain them someday */
        char mze_name[MZAP_NAME_LEN];
} mzap_ent_phys_t;

typedef struct mzap_phys {
        uint64_t mz_block_type; /* ZBT_MICRO */
        uint64_t mz_salt;
        uint64_t mz_pad[6];
        mzap_ent_phys_t mz_chunk[1];
        /* actually variable size depending on block size */
} mzap_phys_t;

/*
 * The (fat) zap is stored in one object. It is an array of
 * 1<<FZAP_BLOCK_SHIFT byte blocks. The layout looks like one of:
 *
 * ptrtbl fits in first block:
 *      [zap_phys_t zap_ptrtbl_shift < 6] [zap_leaf_t] ...
 *
 * ptrtbl too big for first block:
 *      [zap_phys_t zap_ptrtbl_shift >= 6] [zap_leaf_t] [ptrtbl] ...
 *
 */

#define ZBT_LEAF                ((1ULL << 63) + 0)
#define ZBT_HEADER              ((1ULL << 63) + 1)
#define ZBT_MICRO               ((1ULL << 63) + 3)
/* any other values are ptrtbl blocks */

/*
 * the embedded pointer table takes up half a block:
 * block size / entry size (2^3) / 2
 */
#define ZAP_EMBEDDED_PTRTBL_SHIFT(zap) (FZAP_BLOCK_SHIFT(zap) - 3 - 1)

/*
 * The embedded pointer table starts half-way through the block.  Since
 * the pointer table itself is half the block, it starts at (64-bit)
 * word number (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap)).
 */
#define ZAP_EMBEDDED_PTRTBL_ENT(zap, idx) \
        ((uint64_t *)(zap)->zap_f.zap_phys) \
        [(idx) + (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap))]

/*
 * TAKE NOTE:
 * If zap_phys_t is modified, zap_byteswap() must be modified.
 */
typedef struct zap_phys {
        uint64_t zap_block_type;        /* ZBT_HEADER */
        uint64_t zap_magic;             /* ZAP_MAGIC */

        struct zap_table_phys {
                uint64_t zt_blk;        /* starting block number */
                uint64_t zt_numblks;    /* number of blocks */
                uint64_t zt_shift;      /* bits to index it */
                uint64_t zt_nextblk;    /* next (larger) copy start block */
                uint64_t zt_blks_copied; /* number source blocks copied */
        } zap_ptrtbl;

        uint64_t zap_freeblk;           /* the next free block */
        uint64_t zap_num_leafs;         /* number of leafs */
        uint64_t zap_num_entries;       /* number of entries */
        uint64_t zap_salt;              /* salt to stir into hash function */
        uint64_t zap_normflags;         /* flags for u8_textprep_str() */
        uint64_t zap_flags;             /* zap_flag_t */
        /*
         * This structure is followed by padding, and then the embedded
         * pointer table.  The embedded pointer table takes up second
         * half of the block.  It is accessed using the
         * ZAP_EMBEDDED_PTRTBL_ENT() macro.
         */
} zap_phys_t;

#endif /* _SYS_ZAP_IMPL_H */