Move newlib syscall implementation outside core archive

Due to a bug in the arm none eabi gcc with lto which raise
an unresolved reference if syscall is in the archive (_sbrk,...)

See:
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka15833.html

Signed-off-by: Frederic Pillon <[email protected]>

Author: fpistm

libraries/SrcWrapper/src/syscalls.c

@@ -0,0 +1,112 @@
+/**
+  * \file syscalls_stm32.c
+  *
+  * Implementation of newlib syscall.
+  *
+  */
+
+#include "stm32_def.h"
+#if defined (  __GNUC__  ) /* GCC CS3 */
+#include <sys/stat.h>
+#endif
+#include <errno.h>
+#undef errno
+extern int errno;
+
+extern size_t uart_debug_write(uint8_t *data, uint32_t size);
+
+// Helper macro to mark unused parameters and prevent compiler warnings.
+// Appends _UNUSED to the variable name to prevent accidentally using them.
+#ifdef UNUSED
+#undef UNUSED
+#endif
+#ifdef __GNUC__
+#define UNUSED(x) x ## _UNUSED __attribute__((__unused__))
+#else
+#define UNUSED(x) x ## _UNUSED
+#endif
+
+__attribute__((weak))
+caddr_t _sbrk(int incr)
+{
+  extern char _estack; /* Defined in the linker script */
+  extern char _Min_Stack_Size; /* Defined in the linker script */
+  extern char _end; /* Defined by the linker */
+  static char *heap_end = &_end ;
+  char *prev_heap_end = heap_end;
+
+  if (heap_end + incr > (char *)__get_MSP()) {
+    /* Heap and stack collision */
+    errno = ENOMEM;
+    return (caddr_t) -1;
+  }
+  /* Ensure to keep minimun stack size defined in the linker script */
+  if (heap_end + incr >= (char *)(&_estack - &_Min_Stack_Size)) {
+    errno = ENOMEM;
+    return (caddr_t) -1;
+  }
+
+  heap_end += incr ;
+  return (caddr_t) prev_heap_end ;
+}
+
+__attribute__((weak))
+int _close(UNUSED(int file))
+{
+  return -1;
+}
+
+__attribute__((weak))
+int _fstat(UNUSED(int file), struct stat *st)
+{
+  st->st_mode = S_IFCHR ;
+  return 0;
+}
+
+__attribute__((weak))
+int _isatty(UNUSED(int file))
+{
+  return 1;
+}
+
+__attribute__((weak))
+int _lseek(UNUSED(int file), UNUSED(int ptr), UNUSED(int dir))
+{
+  return 0;
+}
+
+__attribute__((weak))
+int _read(UNUSED(int file), UNUSED(char *ptr), UNUSED(int len))
+{
+  return 0;
+}
+
+__attribute__((weak))
+int _write(UNUSED(int file), char *ptr, int len)
+{
+#ifdef HAL_UART_MODULE_ENABLED
+  return uart_debug_write((uint8_t *)ptr, (uint32_t)len);
+#else
+  (void)ptr;
+  return len;
+#endif
+}
+
+__attribute__((weak))
+void _exit(UNUSED(int status))
+{
+  for (; ;) ;
+}
+
+__attribute__((weak))
+int _kill(UNUSED(int pid), UNUSED(int sig))
+{
+  errno = EINVAL;
+  return -1;
+}
+
+__attribute__((weak))
+int _getpid(void)
+{
+  return 1;
+}