Reset cause for STM32

firmware/hw_layer/hardware.cpp

@@ -610,3 +610,14 @@ int getSpiPrescaler(spi_speed_e speed, spi_device_e device) {
 }
 
 #endif /* HAL_USE_SPI */
+
+void checkLastResetCause() {
+	Reset_Cause_t cause = getMCUResetCause();
+	const char *causeStr = getMCUResetCause(cause);
+	efiPrintf("Last Reset Cause: %s", causeStr);
+
+	// if reset by watchdog, signal a fatal error
+	if (cause == Reset_Cause_IWatchdog || cause == Reset_Cause_WWatchdog) {
+		firmwareError(ObdCode::OBD_PCM_Processor_Fault, "Watchdog Reset");
+	}
+}

firmware/hw_layer/hardware.h

@@ -52,6 +52,8 @@ void initHardwareNoConfig();
 // Initialize hardware with configuration loaded
 void initHardware();
 
+void checkLastResetCause();
+
 // todo: can we do simpler here? move conditional compilation into debounce.h?
 #if EFI_PROD_CODE
 #include "debounce.h"

firmware/hw_layer/ports/mpu_util.h

@@ -91,6 +91,22 @@ typedef enum {
 BOR_Level_t BOR_Get(void);
 BOR_Result_t BOR_Set(BOR_Level_t BORValue);
 
+// Reset Cause
+typedef enum {
+	Reset_Cause_Unknown = 0,
+	Reset_Cause_IWatchdog,		// Independent hardware watchdog (we use it)
+	Reset_Cause_WWatchdog,		// Window watchdog
+	Reset_Cause_Soft_Reset,		// NVIC_SystemReset or by debugger
+	Reset_Cause_NRST_Pin,		// Reset from NRST pin
+	Reset_Cause_Illegal_Mode,	// Reset after illegal Stop, Standby or Shutdown mode entry
+	Reset_Cause_BOR,			// BOR reset
+	Reset_Cause_Firewall,		// Firewall reset
+	Reset_Cause_Option_Byte,	// Option byte load reset
+} Reset_Cause_t;
+
+Reset_Cause_t getMCUResetCause();
+const char *getMCUResetCause(Reset_Cause_t cause);
+
 #ifdef AT32F4XX
 int at32GetMcuType(uint32_t id, const char **pn, const char **package, uint32_t *flashSize);
 int at32GetRamSizeKb(void);

firmware/hw_layer/ports/stm32/stm32_common.mk

@@ -10,6 +10,7 @@ HW_LAYER_PORT_CPP += \
 	$(HW_STM32_PORT_DIR)/stm32_serial.cpp \
 	$(HW_STM32_PORT_DIR)/stm32_spi.cpp \
 	$(HW_STM32_PORT_DIR)/stm32_icu.cpp \
+	$(HW_STM32_PORT_DIR)/stm32_reset_cause.cpp \
 	$(HW_STM32_PORT_DIR)/backup_ram.cpp \
 	$(HW_STM32_PORT_DIR)/microsecond_timer_stm32.cpp \
 	$(HW_STM32_PORT_DIR)/osc_detector.cpp \

firmware/hw_layer/ports/stm32/stm32_reset_cause.cpp

@@ -0,0 +1,67 @@
+/**
+ * @file	stm32_reset_cause.cpp
+ * @brief	Get Reset Cause for STM32 MCUs
+ *
+ * @date Dec 10, 2023
+ * @author Andrey Belomutskiy, (c) 2012-2023
+ * @author  andreika <prometheus.pcb@gmail.com>
+ */
+
+#include "pch.h"
+
+#if EFI_PROD_CODE
+#include "mpu_util.h"
+#endif  /* EFI_PROD_CODE */
+
+
+static Reset_Cause_t readMCUResetCause() {
+	uint32_t cause = RCC->CSR; // Read the Control/Status Register
+	// Clear reset flags for future reset detection
+	RCC->CSR |= RCC_CSR_RMVF;
+
+	if (cause & RCC_CSR_IWDGRSTF) {
+		return Reset_Cause_IWatchdog;
+    } else if (cause & RCC_CSR_WWDGRSTF) {
+        return Reset_Cause_WWatchdog;
+    } else if (cause & RCC_CSR_SFTRSTF) {
+    	return Reset_Cause_Soft_Reset;
+    } else if (cause & RCC_CSR_PINRSTF) {
+		return Reset_Cause_NRST_Pin;
+	} else if (cause & RCC_CSR_LPWRRSTF) {
+		return Reset_Cause_Illegal_Mode;
+	} else if (cause & RCC_CSR_BORRSTF) {
+		return Reset_Cause_BOR;
+	}
+    return Reset_Cause_Unknown;
+}
+
+// we need to read the reset cause on the early stage, before we setup the rest of MCU hardware
+static Reset_Cause_t resetCause = readMCUResetCause();
+
+Reset_Cause_t getMCUResetCause() {
+	return resetCause;
+}
+
+const char *getMCUResetCause(Reset_Cause_t cause) {
+	switch (cause) {
+	case Reset_Cause_IWatchdog:
+		return "Independent hardware watchdog";
+	case Reset_Cause_WWatchdog:
+		return "Window watchdog";
+	case Reset_Cause_Soft_Reset:
+		return "NVIC_SystemReset or by debugger";
+	case Reset_Cause_NRST_Pin:
+		return "Reset from NRST pin";
+	case Reset_Cause_Illegal_Mode:
+		return "Reset after illegal Stop, Standby or Shutdown mode entry";
+	case Reset_Cause_BOR:
+		return "BOR reset";
+	case Reset_Cause_Firewall:
+		return "Firewall reset";
+	case Reset_Cause_Option_Byte:
+		return "Option byte load reset";
+	default:
+		return "Unknown";
+	}
+}
+

firmware/rusefi.cpp

@@ -220,6 +220,8 @@ void runRusEfi() {
 	 */
 	initializeConsole();
 
+	checkLastResetCause();
+
 	// Read configuration from flash memory
 	loadConfiguration();