1/* 2 * Copyright (c) 2000, 2005 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. Please obtain a copy of the License at 10 * http://www.opensource.apple.com/apsl/ and read it before using this 11 * file. 12 * 13 * The Original Code and all software distributed under the License are 14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 18 * Please see the License for the specific language governing rights and 19 * limitations under the License. 20 * 21 * @APPLE_LICENSE_HEADER_END@ 22 */ 23#ifndef __HFS_ENDIAN_H__ 24#define __HFS_ENDIAN_H__ 25 26/* 27 * hfs_endian.h 28 * 29 * This file prototypes endian swapping routines for the HFS/HFS Plus 30 * volume format. 31 */ 32#include <hfs/hfs_format.h> 33#include <libkern/OSByteOrder.h> 34#include "SRuntime.h" 35 36/*********************/ 37/* BIG ENDIAN Macros */ 38/*********************/ 39#define SWAP_BE16(__a) OSSwapBigToHostInt16 (__a) 40#define SWAP_BE32(__a) OSSwapBigToHostInt32 (__a) 41#define SWAP_BE64(__a) OSSwapBigToHostInt64 (__a) 42 43#if BYTE_ORDER == BIG_ENDIAN 44 45 /* HFS is always big endian, no swapping needed */ 46 #define SWAP_HFSMDB(__a) 47 #define SWAP_HFSPLUSVH(__a) 48 49/************************/ 50/* LITTLE ENDIAN Macros */ 51/************************/ 52#elif BYTE_ORDER == LITTLE_ENDIAN 53 54 #define SWAP_HFSMDB(__a) hfs_swap_HFSMasterDirectoryBlock ((__a)) 55 #define SWAP_HFSPLUSVH(__a) hfs_swap_HFSPlusVolumeHeader ((__a)) 56 57#else 58#warning Unknown byte order 59#error 60#endif 61 62#ifdef __cplusplus 63extern "C" { 64#endif 65 66/* 67 * Constants for the "unswap" argument to hfs_swap_BTNode: 68 */ 69enum HFSBTSwapDirection { 70 kSwapBTNodeBigToHost = 0, 71 kSwapBTNodeHostToBig = 1, 72 73 /* 74 * kSwapBTNodeHeaderRecordOnly is used to swap just the header record 75 * of a header node from big endian (on disk) to host endian (in memory). 76 * It does not swap the node descriptor (forward/backward links, record 77 * count, etc.). It assumes the header record is at offset 0x000E. 78 * 79 * Since HFS Plus doesn't have fixed B-tree node sizes, we have to read 80 * the header record to determine the actual node size for that tree 81 * before we can set up the B-tree control block. We read it initially 82 * as 512 bytes, then re-read it once we know the correct node size. Since 83 * we may not have read the entire header node the first time, we can't 84 * swap the record offsets, other records, or do most sanity checks. 85 */ 86 kSwapBTNodeHeaderRecordOnly = 3 87}; 88 89void hfs_swap_HFSMasterDirectoryBlock (void *buf); 90void hfs_swap_HFSPlusVolumeHeader (void *buf); 91int hfs_swap_BTNode (BlockDescriptor *src, SFCB *fcb, enum HFSBTSwapDirection direction); 92 93#ifdef __cplusplus 94} 95#endif 96 97#endif /* __HFS_FORMAT__ */ 98