nes-proj/os/lib/newlib/syscalls.c

93 lines
3.0 KiB
C
Raw Normal View History

2015-05-26 18:03:37 +00:00
/*
* Copyright (c) 2014, Institute for Pervasive Computing, ETH Zurich.
* All rights reserved.
*
* Author: Andreas Dröscher <contiki@anticat.ch>
*
* 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. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS "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 INSTITUTE OR CONTRIBUTORS 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.
*/
/**
* \addtogroup lib
* @{
*
* \defgroup newlib Generic Newlib customizations
*
* Library providing generic implementations of Newlib features for Contiki
* @{
*
* \file
* System calls
*/
#include <sys/types.h>
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
/*---------------------------------------------------------------------------*/
#define DEBUG 0
#if DEBUG
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif
/*---------------------------------------------------------------------------*/
/**
* \brief Enlarges the allocated heap space
* \param incr Number of bytes by which to increase the heap space
* \return The previous end of heap on success (which is also a pointer to the
* start of the newly allocated memory if \p incr is positive), or
* <tt>(caddr_t)-1</tt> with \c errno set to \c ENOMEM on error
*/
caddr_t
_sbrk(int incr)
{
/*
* Newlib's _sbrk_r() assumes that this global errno variable is used here,
* which is different from the errno definition provided by <errno.h>.
*/
#undef errno
extern int errno;
/* Heap boundaries from linker script. */
extern uint8_t _heap;
extern uint8_t _eheap;
static uint8_t *heap_end = &_heap;
uint8_t *prev_heap_end = heap_end;
if(heap_end + incr > &_eheap) {
PRINTF("Out of heap space!\n");
errno = ENOMEM;
return (caddr_t)-1;
}
heap_end += incr;
return (caddr_t)prev_heap_end;
}
/**
* @}
* @}
*/