From c81165d99221b3b3bc05b22946fc3de13956a132 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Igor=20Mi=C5=A1i=C4=87?= <igy1000mb@gmail.com>
Date: Mon, 25 Sep 2023 17:26:36 +0200
Subject: [PATCH] test for MISRA

---
 Inc/crc/crc32_variants/crc32.h |  3 ++-
 Src/crc/crc32_variants/crc32.c | 21 ++++++++++++++++++---
 Tests/test_crc32.c             | 21 ++++++++++++++-------
 3 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/Inc/crc/crc32_variants/crc32.h b/Inc/crc/crc32_variants/crc32.h
index bb5d561..1f9da99 100644
--- a/Inc/crc/crc32_variants/crc32.h
+++ b/Inc/crc/crc32_variants/crc32.h
@@ -57,7 +57,8 @@
 uint32_t Crc32(
     const uint8_t* crc_data_ptr,
     uint32_t crc_length,
-    bool final_xor
+    bool final_crc,
+    const uint32_t* last_crc_value
 );
 
 #endif /* UTILITY_CRC32_H_ */
diff --git a/Src/crc/crc32_variants/crc32.c b/Src/crc/crc32_variants/crc32.c
index 5a94414..6c421af 100644
--- a/Src/crc/crc32_variants/crc32.c
+++ b/Src/crc/crc32_variants/crc32.c
@@ -40,12 +40,14 @@
 #define FINAL_XOR_VALUE (0xFFFFFFFFU)
 #define REFLECTED_OUTPUT (true)
 #define REFLECTED_INPUT (true)
+#define FINAL_XOR (true)
 
 uint32_t
 Crc32(
     const uint8_t* crc_data_ptr,
     uint32_t crc_length,
-    bool final_xor) {
+    bool final_crc,
+    const uint32_t* last_crc_value) {
 
     /* CRC32 also know as Ethernet CRC (Polynomial 0x4C11DB7) */
     static const uint32_t crc_table[256] = {
@@ -83,13 +85,26 @@ Crc32(
         0xAFB010B1U, 0xAB710D06U, 0xA6322BDFU, 0xA2F33668U, 0xBCB4666DU, 0xB8757BDAU, 0xB5365D03U, 0xB1F740B4U
     };
 
+    bool reflect_output = false;
+    bool final_xor = false;
+    uint32_t crc_initial_value = INITIAL_CRC32_VALUE;
+
+    if (NULL_PTR != last_crc_value) {
+        crc_initial_value = *last_crc_value;
+    }
+
+    if (final_crc) {
+        reflect_output = REFLECTED_OUTPUT;
+        final_xor = FINAL_XOR;
+    }
+
     return Crc32Base(
                crc_table,
                crc_data_ptr,
                crc_length,
-               INITIAL_CRC32_VALUE,
+               crc_initial_value,
                FINAL_XOR_VALUE,
-               REFLECTED_OUTPUT,
+               reflect_output,
                REFLECTED_INPUT,
                final_xor
            );
diff --git a/Tests/test_crc32.c b/Tests/test_crc32.c
index 7529f90..89e99db 100644
--- a/Tests/test_crc32.c
+++ b/Tests/test_crc32.c
@@ -162,13 +162,20 @@ TEST(Crc32, CRC32Base_Without_finish_xor) {
 }
 
 TEST(Crc32, Crc32) {
-    TEST_ASSERT_EQUAL_HEX32(0x2144DF1CU, Crc32(message1, sizeof(message1), true));
-    TEST_ASSERT_EQUAL_HEX32(0x24AB9D77U, Crc32(message2, sizeof(message2), true));
-    TEST_ASSERT_EQUAL_HEX32(0xB6C9B287U, Crc32(message3, sizeof(message3), true));
-    TEST_ASSERT_EQUAL_HEX32(0x32A06212U, Crc32(message4, sizeof(message4), true));
-    TEST_ASSERT_EQUAL_HEX32(0xB0AE863DU, Crc32(message5, sizeof(message5), true));
-    TEST_ASSERT_EQUAL_HEX32(0x9CDEA29BU, Crc32(message6, sizeof(message6), true));
-    TEST_ASSERT_EQUAL_HEX32(0xFFFFFFFFU, Crc32(message7, sizeof(message7), true));
+    TEST_ASSERT_EQUAL_HEX32(0x2144DF1CU, Crc32(message1, sizeof(message1), true, NULL_PTR));
+    TEST_ASSERT_EQUAL_HEX32(0x24AB9D77U, Crc32(message2, sizeof(message2), true, NULL_PTR));
+    TEST_ASSERT_EQUAL_HEX32(0xB6C9B287U, Crc32(message3, sizeof(message3), true, NULL_PTR));
+    TEST_ASSERT_EQUAL_HEX32(0x32A06212U, Crc32(message4, sizeof(message4), true, NULL_PTR));
+    TEST_ASSERT_EQUAL_HEX32(0xB0AE863DU, Crc32(message5, sizeof(message5), true, NULL_PTR));
+    TEST_ASSERT_EQUAL_HEX32(0x9CDEA29BU, Crc32(message6, sizeof(message6), true, NULL_PTR));
+    TEST_ASSERT_EQUAL_HEX32(0xFFFFFFFFU, Crc32(message7, sizeof(message7), true, NULL_PTR));
+
+    // CRC when message is in chunks
+    uint32_t crc_result = Crc32(&message5[0], 2U, false, NULL_PTR);
+    crc_result = Crc32(&message5[2], 5U, false, &crc_result);
+    crc_result = Crc32(&message5[7], 2U, true, &crc_result);
+
+    TEST_ASSERT_EQUAL_HEX32(0xB0AE863DU, crc_result);
 }
 
 TEST(Crc32, Crc32_bzip2) {