stm-firmware/include/reflow-controller/safety/safety-memory.h

@@ -55,7 +55,7 @@ struct safety_memory_header {
 	uint32_t config_overrides_len;	/**< @brief Length of override entries in words */
 	uint32_t err_memory_offset;	/**< @brief Offset of the error memory */
 	uint32_t err_memory_end;	/**< @brief End of the error memory. This points to the word after the error memory, containing the CRC of the whole backup RAM. */
-	uint32_t crc;		/**< @brief  CRC of the header */
+	uint32_t magic_i;		/**< @brief Invers Magic. Set to the bitwise inverse of @ref SAFETY_MEMORY_MAGIC */
 };
 
 struct safety_memory_boot_status {

stm-firmware/safety/fault.c

@@ -26,16 +26,14 @@
 
 void HardFault_Handler(void)
 {
-	/* This is a non recoverable fault. Stop the oven */
+	/* This is a non recoverable fault. Hang here */
 
 	oven_driver_set_power(0);
 	oven_driver_apply_power_level();
 
-	/* Set the error led */
 	led_set(0, 1);
 
-	/* Try the real panic mode */
-	panic_mode();
+	while (1);
 }
 
 /* Overwrite default handler. Go to panic mode */
@@ -46,9 +44,12 @@ void __int_default_handler(void)
 
 void panic_mode(void)
 {
-	/* This variable is static, because I don't want it to be on the stack */
 	static struct safety_memory_boot_status IN_SECTION(.ccm.bss) boot_status;
 
+	/* Panic mode is esentially the same as a hardfault,
+	 * but it can be expected, that more functionality is still usable
+	 */
+
 	oven_driver_set_power(0);
 	oven_driver_apply_power_level();
 
@@ -58,6 +59,6 @@ void panic_mode(void)
 		(void)safety_memory_set_boot_status(&boot_status);
 	}
 
-	/* Let the watchdog do the rest */
+
 	while (1);
 }

stm-firmware/safety/safety-memory.c

@@ -76,21 +76,13 @@ static enum safety_memory_state safety_memory_get_header(struct safety_memory_he
 	if (res)
 		return SAFETY_MEMORY_INIT_CORRUPTED;
 
-	/* Check magic */
-	if (header->magic != SAFETY_MEMORY_MAGIC) {
-		/* Magic invalid */
+	/* Check magics */
+	if (header->magic != SAFETY_MEMORY_MAGIC || header->magic_i != (uint32_t)(~SAFETY_MEMORY_MAGIC)) {
+		/* Magics invalid */
 		ret = SAFETY_MEMORY_INIT_FRESH;
 		goto return_val;
 	}
 
-	/* Check the header crc */
-	crc_unit_reset();
-	crc_unit_input_array((uint32_t *)header, wordsize_of(struct safety_memory_header));
-	if (crc_unit_get_crc() != 0UL) {
-		ret = SAFETY_MEMORY_INIT_CORRUPTED;
-		goto return_val;
-	}
-
 	res = 0;
 	if (header->boot_status_offset < wordsize_of(struct safety_memory_header))
 		res++;
@@ -114,14 +106,8 @@ return_val:
 	return ret;
 }
 
-static void safety_memory_write_and_patch_header(struct safety_memory_header *header)
+static void safety_memory_write_header(const struct safety_memory_header *header)
 {
-	/* Patch the CRC */
-	crc_unit_reset();
-	crc_unit_input_array((uint32_t *)header, wordsize_of(struct safety_memory_header) - 1U);
-	header->crc = crc_unit_get_crc();
-
-	/* Write to memory */
 	backup_ram_write_data(0UL, (uint32_t *)header, wordsize_of(*header));
 }
 
@@ -135,9 +121,10 @@ static void safety_memory_write_new_header(void)
 	header.err_memory_offset = header.config_overrides_offset + SAFETY_MEMORY_CONFIG_OVERRIDE_COUNT;
 	header.err_memory_end = header.err_memory_offset;
 	header.magic = SAFETY_MEMORY_MAGIC;
+	header.magic_i = ~SAFETY_MEMORY_MAGIC;
 
 	backup_ram_wipe();
-	safety_memory_write_and_patch_header(&header);
+	safety_memory_write_header(&header);
 }
 
 static int safety_memory_check_crc()
@@ -412,7 +399,7 @@ int safety_memory_insert_error_entry(struct error_memory_entry *entry)
 			/* Still fits in memory */
 			backup_ram_write_data(header.err_memory_end, &input_data, 1UL);
 			header.err_memory_end++;
-			safety_memory_write_and_patch_header(&header);
+			safety_memory_write_header(&header);
 			safety_memory_gen_crc();
 			ret = 0;
 		}
@@ -448,7 +435,7 @@ int safety_memory_insert_error_entry(struct error_memory_entry *entry)
 			if ((addr + 1) < backup_ram_get_size_in_words()) {
 				backup_ram_write_data(addr, &input_data, 1UL);
 				header.err_memory_end++;
-				safety_memory_write_and_patch_header(&header);
+				safety_memory_write_header(&header);
 			} else {
 				ret = -3;
 				goto return_value;