arch.h

00001 /**
00002  * @file
00003  * Support for different processor and compiler architectures
00004  */
00005 
00006 /*
00007  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00008  * All rights reserved.
00009  *
00010  * Redistribution and use in source and binary forms, with or without modification,
00011  * are permitted provided that the following conditions are met:
00012  *
00013  * 1. Redistributions of source code must retain the above copyright notice,
00014  *    this list of conditions and the following disclaimer.
00015  * 2. Redistributions in binary form must reproduce the above copyright notice,
00016  *    this list of conditions and the following disclaimer in the documentation
00017  *    and/or other materials provided with the distribution.
00018  * 3. The name of the author may not be used to endorse or promote products
00019  *    derived from this software without specific prior written permission.
00020  *
00021  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00022  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00023  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00024  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00025  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00026  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00027  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00028  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00029  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00030  * OF SUCH DAMAGE.
00031  *
00032  * This file is part of the lwIP TCP/IP stack.
00033  *
00034  * Author: Adam Dunkels <adam@sics.se>
00035  *
00036  */
00037 #ifndef LWIP_HDR_ARCH_H
00038 #define LWIP_HDR_ARCH_H
00039 
00040 #ifndef LITTLE_ENDIAN
00041 #define LITTLE_ENDIAN 1234
00042 #endif
00043 
00044 #ifndef BIG_ENDIAN
00045 #define BIG_ENDIAN 4321
00046 #endif
00047 
00048 #include "arch/cc.h"
00049 
00050 /**
00051  * @defgroup compiler_abstraction Compiler/platform abstraction
00052  * @ingroup sys_layer
00053  * All defines related to this section must not be placed in lwipopts.h,
00054  * but in arch/cc.h!
00055  * These options cannot be \#defined in lwipopts.h since they are not options
00056  * of lwIP itself, but options of the lwIP port to your system.
00057  * @{
00058  */
00059 
00060 /** Define the byte order of the system.
00061  * Needed for conversion of network data to host byte order.
00062  * Allowed values: LITTLE_ENDIAN and BIG_ENDIAN
00063  */
00064 #ifndef BYTE_ORDER
00065 #define BYTE_ORDER LITTLE_ENDIAN
00066 #endif
00067 
00068 /** Define random number generator function of your system */
00069 #ifdef __DOXYGEN__
00070 #define LWIP_RAND() ((u32_t)rand())
00071 #endif
00072 
00073 /** Platform specific diagnostic output.\n
00074  * Note the default implementation pulls in printf, which may
00075  * in turn pull in a lot of standard libary code. In resource-constrained 
00076  * systems, this should be defined to something less resource-consuming.
00077  */
00078 #ifndef LWIP_PLATFORM_DIAG
00079 #define LWIP_PLATFORM_DIAG(x) do {printf x;} while(0)
00080 #include <stdio.h>
00081 #include <stdlib.h>
00082 #endif
00083 
00084 /** Platform specific assertion handling.\n
00085  * Note the default implementation pulls in printf, fflush and abort, which may
00086  * in turn pull in a lot of standard libary code. In resource-constrained 
00087  * systems, this should be defined to something less resource-consuming.
00088  */
00089 #ifndef LWIP_PLATFORM_ASSERT
00090 #define LWIP_PLATFORM_ASSERT(x) do {printf("Assertion \"%s\" failed at line %d in %s\n", \
00091                                      x, __LINE__, __FILE__); fflush(NULL); abort();} while(0)
00092 #include <stdio.h>
00093 #include <stdlib.h>
00094 #endif
00095 
00096 /** Define this to 1 in arch/cc.h of your port if you do not want to
00097  * include stddef.h header to get size_t. You need to typedef size_t
00098  * by yourself in this case.
00099  */
00100 #ifndef LWIP_NO_STDDEF_H
00101 #define LWIP_NO_STDDEF_H 0
00102 #endif
00103 
00104 #if !LWIP_NO_STDDEF_H
00105 #include <stddef.h> /* for size_t */
00106 #endif
00107 
00108 /** Define this to 1 in arch/cc.h of your port if your compiler does not provide
00109  * the stdint.h header. You need to typedef the generic types listed in
00110  * lwip/arch.h yourself in this case (u8_t, u16_t...).
00111  */
00112 #ifndef LWIP_NO_STDINT_H
00113 #define LWIP_NO_STDINT_H 0
00114 #endif
00115 
00116 /* Define generic types used in lwIP */
00117 #if !LWIP_NO_STDINT_H
00118 #include <stdint.h>
00119 typedef uint8_t   u8_t;
00120 typedef int8_t    s8_t;
00121 typedef uint16_t  u16_t;
00122 typedef int16_t   s16_t;
00123 typedef uint32_t  u32_t;
00124 typedef int32_t   s32_t;
00125 typedef uintptr_t mem_ptr_t;
00126 #endif
00127 
00128 /** Define this to 1 in arch/cc.h of your port if your compiler does not provide
00129  * the inttypes.h header. You need to define the format strings listed in
00130  * lwip/arch.h yourself in this case (X8_F, U16_F...).
00131  */
00132 #ifndef LWIP_NO_INTTYPES_H
00133 #define LWIP_NO_INTTYPES_H 0
00134 #endif
00135 
00136 /* Define (sn)printf formatters for these lwIP types */
00137 #if !LWIP_NO_INTTYPES_H
00138 #include <inttypes.h>
00139 #ifndef X8_F
00140 #define X8_F  "02" PRIx8
00141 #endif
00142 #ifndef U16_F
00143 #define U16_F PRIu16
00144 #endif
00145 #ifndef S16_F
00146 #define S16_F PRId16
00147 #endif
00148 #ifndef X16_F
00149 #define X16_F PRIx16
00150 #endif
00151 #ifndef U32_F
00152 #define U32_F PRIu32
00153 #endif
00154 #ifndef S32_F
00155 #define S32_F PRId32
00156 #endif
00157 #ifndef X32_F
00158 #define X32_F PRIx32
00159 #endif
00160 #ifndef SZT_F
00161 #define SZT_F PRIuPTR
00162 #endif
00163 #endif
00164 
00165 /** Define this to 1 in arch/cc.h of your port if your compiler does not provide
00166  * the limits.h header. You need to define the type limits yourself in this case
00167  * (e.g. INT_MAX).
00168  */
00169 #ifndef LWIP_NO_LIMITS_H
00170 #define LWIP_NO_LIMITS_H 0
00171 #endif
00172 
00173 /* Include limits.h? */
00174 #if !LWIP_NO_LIMITS_H
00175 #include <limits.h>
00176 #endif
00177 
00178 /** C++ const_cast<target_type>(val) equivalent to remove constness from a value (GCC -Wcast-qual) */
00179 #ifndef LWIP_CONST_CAST
00180 #define LWIP_CONST_CAST(target_type, val) ((target_type)((ptrdiff_t)val))
00181 #endif
00182 
00183 /** Get rid of alignment cast warnings (GCC -Wcast-align) */
00184 #ifndef LWIP_ALIGNMENT_CAST
00185 #define LWIP_ALIGNMENT_CAST(target_type, val) LWIP_CONST_CAST(target_type, val)
00186 #endif
00187 
00188 /** Get rid of warnings related to pointer-to-numeric and vice-versa casts,
00189  * e.g. "conversion from 'u8_t' to 'void *' of greater size"
00190  */
00191 #ifndef LWIP_PTR_NUMERIC_CAST
00192 #define LWIP_PTR_NUMERIC_CAST(target_type, val) LWIP_CONST_CAST(target_type, val)
00193 #endif
00194 
00195 /** Allocates a memory buffer of specified size that is of sufficient size to align
00196  * its start address using LWIP_MEM_ALIGN.
00197  * You can declare your own version here e.g. to enforce alignment without adding
00198  * trailing padding bytes (see LWIP_MEM_ALIGN_BUFFER) or your own section placement
00199  * requirements.\n
00200  * e.g. if you use gcc and need 32 bit alignment:\n
00201  * \#define LWIP_DECLARE_MEMORY_ALIGNED(variable_name, size) u8_t variable_name[size] \_\_attribute\_\_((aligned(4)))\n
00202  * or more portable:\n
00203  * \#define LWIP_DECLARE_MEMORY_ALIGNED(variable_name, size) u32_t variable_name[(size + sizeof(u32_t) - 1) / sizeof(u32_t)]
00204  */
00205 #ifndef LWIP_DECLARE_MEMORY_ALIGNED
00206 #define LWIP_DECLARE_MEMORY_ALIGNED(variable_name, size) u8_t variable_name[LWIP_MEM_ALIGN_BUFFER(size)]
00207 #endif
00208 
00209 /** Calculate memory size for an aligned buffer - returns the next highest
00210  * multiple of MEM_ALIGNMENT (e.g. LWIP_MEM_ALIGN_SIZE(3) and
00211  * LWIP_MEM_ALIGN_SIZE(4) will both yield 4 for MEM_ALIGNMENT == 4).
00212  */
00213 #ifndef LWIP_MEM_ALIGN_SIZE
00214 #define LWIP_MEM_ALIGN_SIZE(size) (((size) + MEM_ALIGNMENT - 1U) & ~(MEM_ALIGNMENT-1U))
00215 #endif
00216 
00217 /** Calculate safe memory size for an aligned buffer when using an unaligned
00218  * type as storage. This includes a safety-margin on (MEM_ALIGNMENT - 1) at the
00219  * start (e.g. if buffer is u8_t[] and actual data will be u32_t*)
00220  */
00221 #ifndef LWIP_MEM_ALIGN_BUFFER
00222 #define LWIP_MEM_ALIGN_BUFFER(size) (((size) + MEM_ALIGNMENT - 1U))
00223 #endif
00224 
00225 /** Align a memory pointer to the alignment defined by MEM_ALIGNMENT
00226  * so that ADDR % MEM_ALIGNMENT == 0
00227  */
00228 #ifndef LWIP_MEM_ALIGN
00229 #define LWIP_MEM_ALIGN(addr) ((void *)(((mem_ptr_t)(addr) + MEM_ALIGNMENT - 1) & ~(mem_ptr_t)(MEM_ALIGNMENT-1)))
00230 #endif
00231 
00232 #ifdef __cplusplus
00233 extern "C" {
00234 #endif
00235 
00236 /** Packed structs support.
00237   * Placed BEFORE declaration of a packed struct.\n
00238   * For examples of packed struct declarations, see include/lwip/prot/ subfolder.\n
00239   * A port to GCC/clang is included in lwIP, if you use these compilers there is nothing to do here.
00240   */
00241 #ifndef PACK_STRUCT_BEGIN
00242 #define PACK_STRUCT_BEGIN
00243 #endif /* PACK_STRUCT_BEGIN */
00244 
00245 /** Packed structs support.
00246   * Placed AFTER declaration of a packed struct.\n
00247   * For examples of packed struct declarations, see include/lwip/prot/ subfolder.\n
00248   * A port to GCC/clang is included in lwIP, if you use these compilers there is nothing to do here.
00249   */
00250 #ifndef PACK_STRUCT_END
00251 #define PACK_STRUCT_END
00252 #endif /* PACK_STRUCT_END */
00253 
00254 /** Packed structs support.
00255   * Placed between end of declaration of a packed struct and trailing semicolon.\n
00256   * For examples of packed struct declarations, see include/lwip/prot/ subfolder.\n
00257   * A port to GCC/clang is included in lwIP, if you use these compilers there is nothing to do here.
00258   */
00259 #ifndef PACK_STRUCT_STRUCT
00260 #if defined(__GNUC__) || defined(__clang__)
00261 #define PACK_STRUCT_STRUCT __attribute__((packed))
00262 #else
00263 #define PACK_STRUCT_STRUCT
00264 #endif
00265 #endif /* PACK_STRUCT_STRUCT */
00266 
00267 /** Packed structs support.
00268   * Wraps u32_t and u16_t members.\n
00269   * For examples of packed struct declarations, see include/lwip/prot/ subfolder.\n
00270   * A port to GCC/clang is included in lwIP, if you use these compilers there is nothing to do here.
00271   */
00272 #ifndef PACK_STRUCT_FIELD
00273 #define PACK_STRUCT_FIELD(x) x
00274 #endif /* PACK_STRUCT_FIELD */
00275 
00276 /** Packed structs support.
00277   * Wraps u8_t members, where some compilers warn that packing is not necessary.\n
00278   * For examples of packed struct declarations, see include/lwip/prot/ subfolder.\n
00279   * A port to GCC/clang is included in lwIP, if you use these compilers there is nothing to do here.
00280   */
00281 #ifndef PACK_STRUCT_FLD_8
00282 #define PACK_STRUCT_FLD_8(x) PACK_STRUCT_FIELD(x)
00283 #endif /* PACK_STRUCT_FLD_8 */
00284 
00285 /** Packed structs support.
00286   * Wraps members that are packed structs themselves, where some compilers warn that packing is not necessary.\n
00287   * For examples of packed struct declarations, see include/lwip/prot/ subfolder.\n
00288   * A port to GCC/clang is included in lwIP, if you use these compilers there is nothing to do here.
00289   */
00290 #ifndef PACK_STRUCT_FLD_S
00291 #define PACK_STRUCT_FLD_S(x) PACK_STRUCT_FIELD(x)
00292 #endif /* PACK_STRUCT_FLD_S */
00293 
00294 /** Packed structs support using \#include files before and after struct to be packed.\n
00295  * The file included BEFORE the struct is "arch/bpstruct.h".\n
00296  * The file included AFTER the struct is "arch/epstruct.h".\n
00297  * This can be used to implement struct packing on MS Visual C compilers, see
00298  * the Win32 port in the lwIP contrib repository for reference.
00299  * For examples of packed struct declarations, see include/lwip/prot/ subfolder.\n
00300  * A port to GCC/clang is included in lwIP, if you use these compilers there is nothing to do here.
00301  */
00302 #ifdef __DOXYGEN__
00303 #define PACK_STRUCT_USE_INCLUDES
00304 #endif
00305 
00306 /** Eliminates compiler warning about unused arguments (GCC -Wextra -Wunused). */
00307 #ifndef LWIP_UNUSED_ARG
00308 #define LWIP_UNUSED_ARG(x) (void)x
00309 #endif /* LWIP_UNUSED_ARG */
00310 
00311 /**
00312  * @}
00313  */
00314 
00315 #ifdef __cplusplus
00316 }
00317 #endif
00318 
00319 #endif /* LWIP_HDR_ARCH_H */