projects / apple / xnu.git / blame
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|---|---|---|
| 1c79356b A |
1 | /* |
| 2 | * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. | |
| 3 | * | |
| 4 | * @APPLE_LICENSE_HEADER_START@ | |
| 5 | * | |
| 37839358 A |
6 | * The contents of this file constitute Original Code as defined in and |
| 7 | * are subject to the Apple Public Source License Version 1.1 (the | |
| 8 | * "License"). You may not use this file except in compliance with the | |
| 9 | * License. Please obtain a copy of the License at | |
| 10 | * http://www.apple.com/publicsource and read it before using this file. | |
| 1c79356b | 11 | * |
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12 | * This Original Code and all software distributed under the License are |
| 13 | * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
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14 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
| 15 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
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16 | * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the |
| 17 | * License for the specific language governing rights and limitations | |
| 18 | * under the License. | |
| 1c79356b A |
19 | * |
| 20 | * @APPLE_LICENSE_HEADER_END@ | |
| 21 | */ | |
| 22 | /* | |
| 23 | * @OSF_COPYRIGHT@ | |
| 24 | * | |
| 25 | */ | |
| 26 | ||
| 27 | #ifndef _MACHINE_ENDIAN_H_ | |
| 28 | #define _MACHINE_ENDIAN_H_ | |
| 29 | ||
| 30 | /* | |
| 31 | * Definitions for byte order, | |
| 32 | * according to byte significance from low address to high. | |
| 33 | */ | |
| 34 | #define LITTLE_ENDIAN 1234 /* least-significant byte first (vax) */ | |
| 35 | #define BIG_ENDIAN 4321 /* most-significant byte first (IBM, net) */ | |
| 36 | #define PDP_ENDIAN 3412 /* LSB first in word, MSW first in long (pdp) */ | |
| 37 | ||
| 55e303ae | 38 | #ifdef __BIG_ENDIAN__ /* Predefined by compiler */ |
| 1c79356b A |
39 | #define BYTE_ORDER BIG_ENDIAN /* byte order we use on ppc */ |
| 40 | #define ENDIAN BIG | |
| 41 | #else | |
| 42 | #error code has not been ported to little endian targets yet | |
| 43 | #endif | |
| 44 | ||
| 45 | /* | |
| 46 | * Macros for network/external number representation conversion. | |
| 47 | */ | |
| 48 | #if BYTE_ORDER == BIG_ENDIAN && !defined(lint) | |
| 49 | #define ntohl(x) (x) | |
| 50 | #define ntohs(x) (x) | |
| 51 | #define htonl(x) (x) | |
| 52 | #define htons(x) (x) | |
| 53 | ||
| 54 | static __inline__ unsigned int byte_reverse_word(unsigned int word); | |
| 55 | static __inline__ unsigned int byte_reverse_word(unsigned int word) { | |
| 56 | unsigned int result; | |
| 57 | __asm__ volatile("lwbrx %0, 0, %1" : "=r" (result) : "r" (&word)); | |
| 58 | return result; | |
| 59 | } | |
| 60 | ||
| 61 | /* The above function is commutative, so we can use it for | |
| 62 | * translations in both directions (to/from little endianness) | |
| 63 | * Note that htolx and ltohx are probably identical, they are | |
| 64 | * included for completeness. | |
| 65 | */ | |
| 66 | #define htoll(x) byte_reverse_word(x) | |
| 67 | #define htols(x) (byte_reverse_word(x) >> 16) | |
| 68 | #define ltohl(x) htoll(x) | |
| 69 | #define ltohs(x) htols(x) | |
| 70 | ||
| 71 | #define htobl(x) (x) | |
| 72 | #define htobs(x) (x) | |
| 73 | #define btohl(x) (x) | |
| 74 | #define btohs(x) (x) | |
| 75 | ||
| 76 | #else | |
| 77 | unsigned short ntohs(), htons(); | |
| 78 | unsigned long ntohl(), htonl(); | |
| 79 | #endif | |
| 80 | ||
| 81 | /* This defines the order of elements in a bitfield, | |
| 82 | * it is principally used by the SCSI subsystem in | |
| 83 | * the definitions of mapped registers | |
| 84 | */ | |
| 85 | #define BYTE_MSF 1 | |
| 86 | ||
| 87 | #endif /* _MACHINE_ENDIAN_H_ */ |