Implement generic Newlib syscalls

cpu/cc2538/Makefile.cc2538

@@ -77,6 +77,8 @@ CPU_STARTFILES = ${addprefix $(OBJECTDIR)/,${call oname, $(CPU_START_SOURCEFILES
 CONTIKI_SOURCEFILES += $(CONTIKI_CPU_SOURCEFILES) $(DEBUG_IO_SOURCEFILES)
 CONTIKI_SOURCEFILES += $(USB_CORE_SOURCEFILES) $(USB_ARCH_SOURCEFILES)
 
+MODULES += lib/newlib
+
 .SECONDEXPANSION:
 
 ### Don't treat the .elf as intermediate

cpu/cc2538/cc2538.lds

@@ -102,6 +102,9 @@ SECTIONS
         *(.stack)
     } > FRSRAM
 
+    _heap = .;
+    _eheap = ORIGIN(FRSRAM) + LENGTH(FRSRAM);
+
     .nrdata (NOLOAD) :
     {
         _nrdata = .;

lib/newlib/syscalls.c

@@ -0,0 +1,92 @@
+/*
+ * 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;
+}
+
+/**
+ * @}
+ * @}
+ */