libgloss/m32r/sbrk.c

   1 #include <sys/types.h>
   2 #include <sys/stat.h>
   3 #include "syscall.h"
   4 #include "eit.h"
   5 #include <stdlib.h>
   6
   7
   8 extern int _write (int, char *, int);
   9
  10 caddr_t
  11 _sbrk (int incr)
  12 {
  13   /* `_end' is defined in the linker script.
  14      We must handle it carefully as we don't want the compiler to think
  15      it lives in the small data area.  Use medium model to ensure 32 bit
  16      addressability.  */
  17   extern char _end __attribute__ ((__model__(__medium__)));
  18   static char *heap_end;
  19   char *prev_heap_end;
  20   char *sp = (char *)&sp;
  21
  22   if (heap_end == 0)
  23     {
  24       heap_end = &_end;
  25     }
  26   prev_heap_end = heap_end;
  27   if (heap_end > sp)
  28     {
  29       _write (1, "Heap and stack collision\n", 25);
  30 #if 0 /* Calling abort brings in the signal handling code.  */
  31       abort ();
  32 #else
  33       exit (1);
  34 #endif
  35     }
  36   heap_end += incr;
  37   return (caddr_t) prev_heap_end;
  38 }