diff --git a/core/prof/prof.py b/core/prof/prof.py
new file mode 100644
index 0000000000..fcb13017ce
--- /dev/null
+++ b/core/prof/prof.py
@@ -0,0 +1,70 @@
+import sys
+
+import uos
+from uio import open
+
+sys.path.insert(0, uos.getenv("TREZOR_SRC"))
+del uos
+
+
+class Coverage:
+    def __init__(self):
+        self.__files = {}
+
+    def line_tick(self, filename, lineno):
+        if not filename in self.__files:
+            self.__files[filename] = set()
+        self.__files[filename].add(lineno)
+
+    def lines_execution(self):
+        lines_execution = {"lines": {}}
+        lines = lines_execution["lines"]
+        this_file = globals()["__file__"]
+        for filename in self.__files:
+            if not filename == this_file:
+                lines[filename] = list(self.__files[filename])
+
+        return lines_execution
+
+
+class _Prof:
+    trace_count = 0
+    display_flags = 0
+    __coverage = Coverage()
+
+    def trace_tick(self, frame, event, arg):
+        self.trace_count += 1
+
+        # if frame.f_code.co_filename.endswith('/loop.py'):
+        #     print(event, frame.f_code.co_filename, frame.f_lineno)
+
+        if event == "line":
+            self.__coverage.line_tick(frame.f_code.co_filename, frame.f_lineno)
+
+    def coverage_data(self):
+        return self.__coverage.lines_execution()
+
+
+def trace_handler(frame, event, arg):
+    __prof__.trace_tick(frame, event, arg)
+    return trace_handler
+
+
+def atexit():
+    print("\n------------------ script exited ------------------")
+    print("Total traces executed: ", __prof__.trace_count)
+    with open(".coverage", "w") as f:
+        # wtf so private much beautiful wow
+        f.write("!coverage.py: This is a private format, don't read it directly!")
+        # poormans json
+        f.write(str(__prof__.coverage_data()).replace("'", '"'))
+
+
+sys.atexit(atexit)
+
+global __prof__
+if not "__prof__" in globals():
+    __prof__ = _Prof()
+
+sys.settrace(trace_handler)
+import main