fixes: texture unit mem access sometimes going to smem, bilinear texture filtering; new: cache req_id,

runtime/src/vx_syscalls.c

@@ -16,7 +16,10 @@ int _open(const char *name, int flags, int mode) { return -1; }
  
 int _read(int file, char *ptr, int len) { return -1; }
  
-caddr_t _sbrk(int incr) { return 0; }
+caddr_t _sbrk(int incr) { 
+  __asm__ __volatile__("ebreak");
+  return 0; 
+}
  
 int _write(int file, char *ptr, int len) {
     int i;