flash storage uses 32 bit CRC (#3984)

* better flash logic and warning message

* comment

* s

* ssssss

* simplify logic

* use 32 bit crc

* s

* don't test things that don't exist

firmware/controllers/algo/persistent_configuration.h

@@ -15,5 +15,5 @@ typedef struct {
 	int version;
 	int size;
 	persistent_config_s persistentConfiguration;
-	crc_t value;
+	uint32_t value;
 } persistent_config_container_s;

firmware/controllers/flash_main.cpp

@@ -71,8 +71,8 @@ const MFSConfig mfsd_nor_config = {
  * should be in a different sector of flash since complete flash sectors are erased on write.
  */
 
-static crc_t flashStateCrc(const persistent_config_container_s& state) {
-	return calc_crc((const crc_t*) &state.persistentConfiguration, sizeof(persistent_config_s));
+static uint32_t flashStateCrc(const persistent_config_container_s& state) {
+	return crc32(&state.persistentConfiguration, sizeof(persistent_config_s));
 }
 
 #if EFI_FLASH_WRITE_THREAD
@@ -229,7 +229,7 @@ static FlashState readOneConfigurationCopy(flashaddr_t address) {
 
 	if (flashCrc != persistentState.value) {
 		// If the stored crc is all 1s, that probably means the flash is actually blank, not that the crc failed.
-		if (persistentState.value == ((crc_t)-1)) {
+		if (persistentState.value == ((decltype(persistentState.value))-1)) {
 			return FlashState::BlankChip;
 		} else {
 			return FlashState::CrcFailed;
@@ -302,9 +302,7 @@ void readFromFlash() {
 		case FlashState::CrcFailed:
 			warning(CUSTOM_ERR_FLASH_CRC_FAILED, "flash CRC failed");
 			efiPrintf("Need to reset flash to default due to CRC mismatch");
-			// todo: use [[fallthrough]]? jenkins has different version on Windows
-			resetConfigurationExt(DEFAULT_ENGINE_TYPE);
-			break;
+			[[fallthrough]];
 		case FlashState::BlankChip:
 			resetConfigurationExt(DEFAULT_ENGINE_TYPE);
 			break;

firmware/util/math/crc.c

@@ -6,43 +6,6 @@
 
 #include "crc.h"
 
-#define WIDTH  (8)
-#define TOPBIT (1 << (WIDTH - 1))
-#define POLYNOMIAL 0xD8
-
-crc_t calc_crc(const crc_t message[], int nBytes) {
-	crc_t remainder = 0;
-
-	/*
-	 * Perform modulo-2 division, a byte at a time.
-	 */
-	for (int byte = 0; byte < nBytes; ++byte) {
-		/*
-		 * Bring the next byte into the remainder.
-		 */
-		remainder ^= (message[byte] << (WIDTH - 8));
-
-		/*
-		 * Perform modulo-2 division, a bit at a time.
-		 */
-		for (unsigned char bit = 8; bit > 0; --bit) {
-			/*
-			 * Try to divide the current data bit.
-			 */
-			if (remainder & TOPBIT) {
-				remainder = (remainder << 1) ^ POLYNOMIAL;
-			} else {
-				remainder = (remainder << 1);
-			}
-		}
-	}
-
-	/*
-	 * The final remainder is the CRC result.
-	 */
-	return remainder;
-}
-
 static const uint32_t crc32_tab[] = { 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
 		0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
 		0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
@@ -95,6 +58,19 @@ uint32_t crc32(const void *buf, uint32_t size) {
 	return crc32inc(buf, 0, size);
 }
 
+uint32_t crc32inc(const void *buf, uint32_t crc, uint32_t size) {
+	const uint8_t *p;
+
+	p = buf;
+	crc = crc ^ 0xFFFFFFFF;
+
+	while (size--) {
+		crc = crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
+	}
+
+	return crc ^ 0xFFFFFFFF;
+}
+
 /**
  * http://www.sunshine2k.de/coding/javascript/crc/crc_js.html
  * https://stackoverflow.com/questions/38639423/understanding-results-of-crc8-sae-j1850-normal-vs-zero
@@ -116,15 +92,3 @@ uint8_t crc8(const uint8_t *data, uint8_t len) {
 	return crc;
 }
 
-uint32_t crc32inc(const void *buf, uint32_t crc, uint32_t size) {
-	const uint8_t *p;
-
-	p = buf;
-	crc = crc ^ 0xFFFFFFFF;
-
-	while (size--) {
-		crc = crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
-	}
-
-	return crc ^ 0xFFFFFFFF;
-}

firmware/util/math/crc.h

@@ -9,13 +9,10 @@
 
 #include "stdint.h"
 
-typedef unsigned char crc_t;
-
 #ifdef __cplusplus
 extern "C" {
 #endif /* __cplusplus */
 
-crc_t calc_crc(const crc_t message[], int nBytes);
 uint8_t crc8(const uint8_t * buf, uint8_t len);
 uint32_t crc32(const void *buf, uint32_t size);
 uint32_t crc32inc(const void *buf, uint32_t crc, uint32_t size);

unit_tests/tests/test_util.cpp

@@ -48,7 +48,6 @@ TEST(util, crc) {
 
 	const char * A = "A";
 
-	ASSERT_EQ( 168,  calc_crc((const crc_t *) A, 1)) << "crc8";
 	uint32_t c = crc32(A, 1);
 	printf("crc32(A)=%x\r\n", c);
 	assertEqualsM("crc32 1", 0xd3d99e8b, c);