Add CRC32 implementation

1 files changed, 45 insertions, 0 deletions

diff --git a/prototype/fw/test/crc32_ref.py b/prototype/fw/test/crc32_ref.py
new file mode 100644
index 0000000..7ac0582
--- /dev/null
+++ b/prototype/fw/test/crc32_ref.py
@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+
+import subprocess
+import zlib
+import os
+import itertools
+import unittest
+
+INTERESTING = bytes([0x00, 0x42, 0xff, 0x01, 0x80])
+
+class RefdataTest(unittest.TestCase):
+    def run_test(self, test_data):
+        ref_val = zlib.crc32(test_data)
+
+        binary = os.environ.get('CRC32_TEST_BINARY', 'build/crc32_test')
+        
+        output = subprocess.check_output(binary, input=test_data)
+        test_val = int(output, 16) & 0xffffffff
+
+        self.assertEqual(test_val, ref_val, f'mismatched results checking input {test_data}')
+
+    def test_empty(self):
+        self.run_test(b'')
+
+    def test_one_byte(self):
+        for x in range(256):
+            self.run_test(bytes([x]))
+
+    def test_two_byte(self):
+        for x, y in itertools.product(INTERESTING, repeat=2):
+            self.run_test(bytes([x, y]))
+
+    def test_three_bytes(self):
+        for x, y, z in itertools.product(INTERESTING, repeat=3):
+            self.run_test(bytes([x, y, z]))
+
+    def test_four_bytes(self):
+        for w, x, y, z in itertools.product(INTERESTING, repeat=4):
+            self.run_test(bytes([w, x, y, z]))
+
+    def test_random_strings(self):
+        for length in range(3, 24):
+            for i in range(20):
+                self.run_test(os.urandom(length))
+