stream: Convert .ioctl() to take fixed number of args.
This is more efficient, as allows to use register calling convention.
If needed, a structure pointer can be passed as argument to pass more
data.
diff --git a/py/obj.h b/py/obj.h
index 592ae8a..ab51234 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -238,7 +238,7 @@
// are implementation-dependent, but will be exposed to user, e.g. via exception).
mp_uint_t (*read)(mp_obj_t obj, void *buf, mp_uint_t size, int *errcode);
mp_uint_t (*write)(mp_obj_t obj, const void *buf, mp_uint_t size, int *errcode);
- mp_uint_t (*ioctl)(mp_obj_t obj, mp_uint_t request, int *errcode, ...);
+ mp_uint_t (*ioctl)(mp_obj_t obj, mp_uint_t request, mp_uint_t arg, int *errcode);
mp_uint_t is_text : 1; // default is bytes, set this for text stream
} mp_stream_p_t;