/*
   *  GRUB  --  GRand Unified Bootloader
   *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
   *

   * SPDX-License-Identifier:	GPL-2.0+

   */
  /*
   * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
   */
  
  #ifndef	_SYS_ZAP_IMPL_H
  #define	_SYS_ZAP_IMPL_H
  
  #define	ZAP_MAGIC 0x2F52AB2ABULL
  
  #define	ZAP_HASHBITS		28
  #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 */