diff --git a/.gitmodules b/.gitmodules
index 07beebb91..075894e4e 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -7,3 +7,6 @@
 [submodule "vendor/micropython"]
 	path = vendor/micropython
 	url = https://github.com/trezor/micropython.git
+[submodule "vendor/norcow"]
+	path = vendor/norcow
+	url = https://github.com/trezor/norcow.git
diff --git a/extmod/modtrezorconfig/modtrezorconfig.c b/extmod/modtrezorconfig/modtrezorconfig.c
index 17fb0b5df..454a35f33 100644
--- a/extmod/modtrezorconfig/modtrezorconfig.c
+++ b/extmod/modtrezorconfig/modtrezorconfig.c
@@ -14,15 +14,9 @@
 #include "py/binary.h"
 #include "py/objstr.h"
 
-#if MICROPY_PY_TREZORCONFIG
-
-
-// temporary function stubs from norcow
-void norcow_init(void) { }
-bool norcow_get(uint16_t key, const void **val, uint32_t *len) { *val = "Works!"; *len = 6; return true; }
-bool norcow_set(uint16_t key, const void *val, uint32_t len) { return true; }
-// end
+#include "norcow.h"
 
+#if MICROPY_PY_TREZORCONFIG
 
 typedef struct _mp_obj_Config_t {
     mp_obj_base_t base;
@@ -79,7 +73,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_TrezorConfig_Config_set_obj, 4, 4
 ///     Erases the whole config (use with caution!)
 ///     '''
 STATIC mp_obj_t mod_TrezorConfig_Config_wipe(mp_obj_t self) {
-    // TODO
+    norcow_wipe();
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_TrezorConfig_Config_wipe_obj, mod_TrezorConfig_Config_wipe);
diff --git a/extmod/modtrezorconfig/norcow.c b/extmod/modtrezorconfig/norcow.c
new file mode 120000
index 000000000..8222de0a6
--- /dev/null
+++ b/extmod/modtrezorconfig/norcow.c
@@ -0,0 +1 @@
+../../vendor/norcow/norcow.c
\ No newline at end of file
diff --git a/extmod/modtrezorconfig/norcow.h b/extmod/modtrezorconfig/norcow.h
new file mode 120000
index 000000000..a4a69374e
--- /dev/null
+++ b/extmod/modtrezorconfig/norcow.h
@@ -0,0 +1 @@
+../../vendor/norcow/norcow.h
\ No newline at end of file
diff --git a/extmod/modtrezorconfig/norcow_config.h b/extmod/modtrezorconfig/norcow_config.h
new file mode 100644
index 000000000..dd0807680
--- /dev/null
+++ b/extmod/modtrezorconfig/norcow_config.h
@@ -0,0 +1,10 @@
+#ifdef UNIX
+#define NORCOW_UNIX 1
+#define NORCOW_FILE "/var/tmp/trezor.config"
+#endif
+
+#ifdef STM32_HAL_H
+// TODO: switch to native implementation when finished
+#define NORCOW_UNIX 1
+#define NORCOW_FILE "/sd/trezor.config"
+#endif
diff --git a/src/trezor/config.py b/src/trezor/config.py
index e7babd2ff..471f64435 100644
--- a/src/trezor/config.py
+++ b/src/trezor/config.py
@@ -1,52 +1,13 @@
-import sys
-import ustruct
+from TrezorConfig import Config
 
-# mock implementation using binary file
+_config = Config()
 
-_mock = {}
+def get(app, key, default=None):
+    v = _config.get(app, key)
+    return v if v else default
 
-if sys.platform in ['trezor', 'pyboard']:  # stmhal
-    _file = '/flash/trezor.config'
-else:
-    _file = '/var/tmp/trezor.config'
-
-
-def _load():
-    global _mock
-    try:
-        with open(_file, 'rb') as f:
-            while True:
-                d = f.read(4)
-                if len(d) != 4:
-                    break
-                k, l = ustruct.unpack('<HH', d)
-                v = f.read(l)
-                _mock[k] = v
-    except OSError:
-        pass
-
-
-def _save():
-    global _mock
-    with open(_file, 'wb') as f:
-        for k, v in _mock.items():
-            f.write(ustruct.pack('<HH', k, len(v)))
-            f.write(v)
-
-_load()
-
-
-def get(app_id, key, default=None):
-    global _mock
-    return _mock.get((app_id << 8) | key, default)
-
-
-def set(app_id, key, value):
-    global _mock
-    _mock[(app_id << 8) | key] = value
-    _save()
+def set(app, key, value):
+    return _config.set(app, key, value)
 
 def wipe():
-    global _mock
-    _mock = {}
-    _save()
+    return _config.wipe()
diff --git a/src/trezor/config.py.real b/src/trezor/config.py.real
deleted file mode 100644
index 471f64435..000000000
--- a/src/trezor/config.py.real
+++ /dev/null
@@ -1,13 +0,0 @@
-from TrezorConfig import Config
-
-_config = Config()
-
-def get(app, key, default=None):
-    v = _config.get(app, key)
-    return v if v else default
-
-def set(app, key, value):
-    return _config.set(app, key, value)
-
-def wipe():
-    return _config.wipe()
diff --git a/tests/test_trezor.config.py b/tests/test_trezor.config.py
index 2ba52d49a..668d9c53f 100644
--- a/tests/test_trezor.config.py
+++ b/tests/test_trezor.config.py
@@ -22,7 +22,7 @@ class TestConfig(unittest.TestCase):
 
     def test_set_get(self):
         config.wipe()
-        for _ in range(128):
+        for _ in range(64):
            appid, key = random.uniform(256), random.uniform(256)
            value = random.bytes(128)
            config.set(appid, key, value)
@@ -31,7 +31,7 @@ class TestConfig(unittest.TestCase):
 
     def test_get_default(self):
         config.wipe()
-        for _ in range(128):
+        for _ in range(64):
            appid, key = random.uniform(256), random.uniform(256)
            value = random.bytes(128)
            value2 = config.get(appid, key, value)
diff --git a/vendor/micropython b/vendor/micropython
index 81e11673b..de483fcc9 160000
--- a/vendor/micropython
+++ b/vendor/micropython
@@ -1 +1 @@
-Subproject commit 81e11673b3b3f8b4cdc5c69585c9c61bf6dc808a
+Subproject commit de483fcc9876fac6aaa98bfd916e5797b13ce7a8
diff --git a/vendor/norcow b/vendor/norcow
new file mode 160000
index 000000000..934b3cd1f
--- /dev/null
+++ b/vendor/norcow
@@ -0,0 +1 @@
+Subproject commit 934b3cd1fbef79fd6b079b787e6e3225bbe5684c