add syscal_newlib for malloc

Author: hathach

cores/nRF5/syscall_newlib.c

@@ -0,0 +1,70 @@
+/**************************************************************************/
+/*!
+    @file     syscall_newlib.c
+    @author   hathach
+
+    @section LICENSE
+
+    Software License Agreement (BSD License)
+
+    Copyright (c) 2017, Adafruit Industries (adafruit.com)
+    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. Neither the name of the copyright holders 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 COPYRIGHT HOLDERS ''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 COPYRIGHT HOLDER 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.
+*/
+/**************************************************************************/
+
+#include <errno.h>
+#include <sys/stat.h>
+#include <malloc.h>
+
+// defined in linker script
+extern unsigned char __HeapBase[];
+extern unsigned char __HeapLimit[];
+
+static unsigned char *sbrk_heap_top = __HeapBase;
+
+//volatile uint32_t first_sbrk = 0;
+//volatile uint32_t last_sbrk = 0;
+
+caddr_t _sbrk( int incr )
+{
+  unsigned char *prev_heap;
+
+  if ( sbrk_heap_top + incr > __HeapLimit )
+  {
+    /* Out of dynamic memory heap space */
+    errno = ENOMEM;
+    return (caddr_t) -1;
+  }
+
+  prev_heap = sbrk_heap_top;
+
+//  if ( !first_sbrk) first_sbrk = sbrk_heap_top;
+//  last_sbrk = sbrk_heap_top;
+
+  sbrk_heap_top += incr;
+
+  return (caddr_t) prev_heap;
+}
+