diff --git a/extmod/modtrezormsg/modtrezormsg.c b/extmod/modtrezormsg/modtrezormsg.c
index 55fea793ec..437e178182 100644
--- a/extmod/modtrezormsg/modtrezormsg.c
+++ b/extmod/modtrezormsg/modtrezormsg.c
@@ -36,6 +36,37 @@ STATIC mp_obj_t mod_TrezorMsg_Msg_make_new(const mp_obj_type_t *type, size_t n_a
     return MP_OBJ_FROM_PTR(o);
 }
 
+/// def trezor.msg.setup(ifaces: list) -> None
+///
+/// Setups USB interfaces with a list of tuples
+///
+STATIC mp_obj_t mod_TrezorMsg_Msg_setup(mp_obj_t self, mp_obj_t ifaces) {
+    mp_uint_t iface_cnt;
+    mp_obj_t *iface;
+    if (MP_OBJ_IS_TYPE(ifaces, &mp_type_tuple)) {
+        mp_obj_tuple_get(ifaces, &iface_cnt, &iface);
+    } else
+    if (MP_OBJ_IS_TYPE(ifaces, &mp_type_list)) {
+        mp_obj_list_get(ifaces, &iface_cnt, &iface);
+    } else {
+        nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "List or tuple expected"));
+    }
+    for (mp_uint_t i = 0; i < iface_cnt; i++) {
+       if (!MP_OBJ_IS_TYPE(iface[i], &mp_type_tuple)) {
+           nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Tuple expected"));
+       }
+       mp_uint_t attr_cnt;
+       mp_obj_t *attr;
+       mp_obj_tuple_get(iface[i], &attr_cnt, &attr);
+       assert(attr_cnt == 2);
+       uint8_t ep = mp_obj_get_int(attr[0]);
+       uint16_t up = mp_obj_get_int(attr[1]);
+       printf("iface %d: ep=%d up=%04x\n", i, ep, up);
+    }
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_TrezorMsg_Msg_setup_obj, mod_TrezorMsg_Msg_setup);
+
 /// def trezor.msg.send(iface: int, message: bytes) -> int
 ///
 /// Sends message using USB HID (device) or UDP (emulator).
@@ -100,6 +131,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_TrezorMsg_Msg_select_obj, mod_TrezorMsg_Msg
 STATIC const mp_rom_map_elem_t mod_TrezorMsg_Msg_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_select), MP_ROM_PTR(&mod_TrezorMsg_Msg_select_obj) },
     { MP_ROM_QSTR(MP_QSTR_send), MP_ROM_PTR(&mod_TrezorMsg_Msg_send_obj) },
+    { MP_ROM_QSTR(MP_QSTR_setup), MP_ROM_PTR(&mod_TrezorMsg_Msg_setup_obj) },
 };
 STATIC MP_DEFINE_CONST_DICT(mod_TrezorMsg_Msg_locals_dict, mod_TrezorMsg_Msg_locals_dict_table);
 
diff --git a/src/main.py b/src/main.py
index 78aa4aaffe..0bd3b8d3f4 100644
--- a/src/main.py
+++ b/src/main.py
@@ -1,4 +1,5 @@
 import trezor.main
+from trezor import msg
 
 # Load all applications
 from apps import homescreen
@@ -10,6 +11,9 @@ homescreen.boot()
 playground.boot()
 # wallet.boot()
 
+# just a demo to show how to register USB ifaces
+msg.setup( [ (1, 0xF53C), (2, 0xF1D0) ] )
+
 # Load default homescreen
 from apps.homescreen.layout_homescreen import layout_homescreen
 
diff --git a/src/trezor/msg.py b/src/trezor/msg.py
index 8cc8fa5bb4..c9dcec3fb0 100644
--- a/src/trezor/msg.py
+++ b/src/trezor/msg.py
@@ -6,6 +6,10 @@ from TrezorMsg import Msg
 _msg = Msg()
 
 
+def setup(ifaces):
+    return _msg.setup(ifaces)
+
+
 def select(timeout_us):
     return _msg.select(timeout_us)