/* System Calls Remapping */#include <sys/stat.h>#include <stdlib.h>void _exit (int n) {label:  goto label; /* endless loop */}register char * stack_ptr asm ("sp");caddr_t _sbrk (int incr) {  extern char   end asm ("end");	/* Defined by the linker */  static char * heap_end;         char * prev_heap_end;  if (heap_end == NULL) heap_end = &end;  prev_heap_end = heap_end;    if (heap_end + incr > stack_ptr) {//  _write (1, "_sbrk: Heap and stack collision\n", 32);    abort ();  }    heap_end += incr;  return (caddr_t) prev_heap_end;}