src/include/lwip/arch.h

/**
 * @file
 * Support for different processor and compiler architectures
 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */
#ifndef LWIP_HDR_ARCH_H
#define LWIP_HDR_ARCH_H

#ifndef LITTLE_ENDIAN
#define LITTLE_ENDIAN 1234
#endif

#ifndef BIG_ENDIAN
#define BIG_ENDIAN 4321
#endif

#include "arch/cc.h"

/** Define this to 1 in arch/cc.h of your port if your compiler does not provide
 * the stdint.h header. This cannot be \#defined in lwipopts.h since
 * this is not an option of lwIP itself, but an option of the lwIP port
 * to your system.
 * Additionally, this header is meant to be \#included in lwipopts.h
 * (you may need to declare function prototypes in there).
 */
#ifndef LWIP_NO_STDINT_H
#define LWIP_NO_STDINT_H 0
#endif

/* Define generic types used in lwIP */
#if !LWIP_NO_STDINT_H
#include <stdint.h>
typedef uint8_t   u8_t;
typedef int8_t    s8_t;
typedef uint16_t  u16_t;
typedef int16_t   s16_t;
typedef uint32_t  u32_t;
typedef int32_t   s32_t;
typedef uintptr_t mem_ptr_t;
#endif

/** Define this to 1 in arch/cc.h of your port if your compiler does not provide
 * the inttypes.h header. This cannot be \#defined in lwipopts.h since
 * this is not an option of lwIP itself, but an option of the lwIP port
 * to your system.
 * Additionally, this header is meant to be \#included in lwipopts.h
 * (you may need to declare function prototypes in there).
 */
#ifndef LWIP_NO_INTTYPES_H
#define LWIP_NO_INTTYPES_H 0
#endif

/* Define (sn)printf formatters for these lwIP types */
#if !LWIP_NO_INTTYPES_H
#include <inttypes.h>
#ifndef X8_F
#define X8_F  "02" PRIx8
#endif
#ifndef U16_F
#define U16_F PRIu16
#endif
#ifndef S16_F
#define S16_F PRId16
#endif
#ifndef X16_F
#define X16_F PRIx16
#endif
#ifndef U32_F
#define U32_F PRIu32
#endif
#ifndef S32_F
#define S32_F PRId32
#endif
#ifndef X32_F
#define X32_F PRIx32
#endif
#ifndef SZT_F
#define SZT_F PRIuPTR
#endif
#endif

/** Allocates a memory buffer of specified size that is of sufficient size to align
 * its start address using LWIP_MEM_ALIGN.
 * You can declare your own version here e.g. to enforce alignment without adding
 * trailing padding bytes (see LWIP_MEM_ALIGN_BUFFER) or your own section placement
 * requirements.
 * e.g. if you use gcc and need 32 bit alignment:
 * \#define LWIP_DECLARE_MEMORY_ALIGNED(variable_name, size) u8_t variable_name[size] __attribute__((aligned(4)))
 * or more portable:
 * \#define LWIP_DECLARE_MEMORY_ALIGNED(variable_name, size) u32_t variable_name[(size + sizeof(u32_t) - 1) / sizeof(u32_t)]
 */
#ifndef LWIP_DECLARE_MEMORY_ALIGNED
#define LWIP_DECLARE_MEMORY_ALIGNED(variable_name, size) u8_t variable_name[LWIP_MEM_ALIGN_BUFFER(size)]
#endif

/** Calculate memory size for an aligned buffer - returns the next highest
 * multiple of MEM_ALIGNMENT (e.g. LWIP_MEM_ALIGN_SIZE(3) and
 * LWIP_MEM_ALIGN_SIZE(4) will both yield 4 for MEM_ALIGNMENT == 4).
 */
#ifndef LWIP_MEM_ALIGN_SIZE
#define LWIP_MEM_ALIGN_SIZE(size) (((size) + MEM_ALIGNMENT - 1U) & ~(MEM_ALIGNMENT-1U))
#endif

/** Calculate safe memory size for an aligned buffer when using an unaligned
 * type as storage. This includes a safety-margin on (MEM_ALIGNMENT - 1) at the
 * start (e.g. if buffer is u8_t[] and actual data will be u32_t*)
 */
#ifndef LWIP_MEM_ALIGN_BUFFER
#define LWIP_MEM_ALIGN_BUFFER(size) (((size) + MEM_ALIGNMENT - 1U))
#endif

/** Align a memory pointer to the alignment defined by MEM_ALIGNMENT
 * so that ADDR % MEM_ALIGNMENT == 0
 */
#ifndef LWIP_MEM_ALIGN
#define LWIP_MEM_ALIGN(addr) ((void *)(((mem_ptr_t)(addr) + MEM_ALIGNMENT - 1) & ~(mem_ptr_t)(MEM_ALIGNMENT-1)))
#endif

#ifdef __cplusplus
extern "C" {
#endif

#ifndef PACK_STRUCT_BEGIN
#define PACK_STRUCT_BEGIN
#endif /* PACK_STRUCT_BEGIN */

#ifndef PACK_STRUCT_END
#define PACK_STRUCT_END
#endif /* PACK_STRUCT_END */

#ifndef PACK_STRUCT_STRUCT
#define PACK_STRUCT_STRUCT
#endif /* PACK_STRUCT_STRUCT */

#ifndef PACK_STRUCT_FIELD
#define PACK_STRUCT_FIELD(x) x
#endif /* PACK_STRUCT_FIELD */

/* Used for struct fields of u8_t,
 * where some compilers warn that packing is not necessary */
#ifndef PACK_STRUCT_FLD_8
#define PACK_STRUCT_FLD_8(x) PACK_STRUCT_FIELD(x)
#endif /* PACK_STRUCT_FLD_8 */

/* Used for struct fields of that are packed structs themself,
 * where some compilers warn that packing is not necessary */
#ifndef PACK_STRUCT_FLD_S
#define PACK_STRUCT_FLD_S(x) PACK_STRUCT_FIELD(x)
#endif /* PACK_STRUCT_FLD_S */


#ifndef LWIP_UNUSED_ARG
#define LWIP_UNUSED_ARG(x) (void)x
#endif /* LWIP_UNUSED_ARG */


#ifdef __cplusplus
}
#endif

#endif /* LWIP_HDR_ARCH_H */