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Reference: Reboot Reason IDs

This page documents identifiers for different reboot reasons. For more information about reboot reason tracking, check out one of these pages:

The table also lists the enum names from the source file reboot_reason_types.h in the MCU SDK.

Expected Reboot Reasons

Name	ID (decimal)	ID (hex)	MCU SDK enum	Notes
Unspecified	0	0x0000	`kMfltRebootReason_Unknown`
User Shutdown	1	0x0001	`kMfltRebootReason_UserShutdown`
User Reset	2	0x0002	`kMfltRebootReason_UserReset`
Firmware Update	3	0x0003	`kMfltRebootReason_FirmwareUpdate`
Low Power	4	0x0004	`kMfltRebootReason_LowPower`	Software shut down due to the battery level being too low.
Debugger Halted	5	0x0005	`kMfltRebootReason_DebuggerHalted`
Button Reset	6	0x0006	`kMfltRebootReason_ButtonReset`
Power On Reset	7	0x0007	`kMfltRebootReason_PowerOnReset`
Software Reset	8	0x0008	`kMfltRebootReason_SoftwareReset`
Deep Sleep	9	0x0009	`kMfltRebootReason_DeepSleep`	CPU went through a full reboot due to exit from lowest power state
Pin Reset	10	0x000A	`kMfltRebootReason_PinReset`	CPU reset pin was toggled
Self Test	11	0x000B	`kMfltRebootReason_SelfTest`	The Self Test component caused a reset

Unexpected Reboot Reasons

Name	ID (decimal)	ID (hex)	MCU SDK enum	Notes
Unexpected Reset	32768	0x8000	`kMfltRebootReason_UnknownError`	Can be used to flag an unexpected reset path, i.e the CPU reset without any reboot logic getting invoked.
Assert	32769	0x8001	`kMfltRebootReason_Assert`
Watchdog (Deprecated)	32770	0x8002	`kMfltRebootReason_WatchdogDeprecated`	Deprecated in favor of HardwareWatchdog & SoftwareWatchdog. This way, the amount of watchdogs not caught by software can be easily tracked.
Brownout Reset	32771	0x8003	`kMfltRebootReason_BrownOutReset`
Nmi	32772	0x8004	`kMfltRebootReason_Nmi`	Non-Maskable Interrupt.
Hardware Watchdog	32773	0x8005	`kMfltRebootReason_HardwareWatchdog`	More details about nomenclature in https://mflt.io/root-cause-watchdogs
Software Watchdog	32774	0x8006	`kMfltRebootReason_SoftwareWatchdog`	More details about nomenclature in https://mflt.io/root-cause-watchdogs
Clock Failure	32775	0x8007	`kMfltRebootReason_ClockFailure`	A reset triggered due to the CPU losing a stable clock. This can happen, for example, if power to the clock is cut or the lock for the PLL is lost.
Kernel Panic	32776	0x8008	`kMfltRebootReason_KernelPanic`	A software reset triggered when the OS or RTOS end-user code is running on top of identifies a fatal error condition.
Firmw Update Error	32777	0x8009	`kMfltRebootReason_FirmwareUpdateError`	A reset triggered when an attempt to upgrade to a new OTA image has failed and a rollback to a previous version was initiated.
Out of Memory	32778	0x800A	`kMfltRebootReason_OutOfMemory`	A software reset triggered due to a dynamic memory (heap) allocation failure.
Stack Overflow	32779	0x800B	`kMfltRebootReason_StackOverflow`	A software reset triggered due to a stack overflow error.

ARM-specific Error Reboot Reasons

Bus Faults

Name	ID (decimal)	ID (hex)	MCU SDK enum
Bus Fault	37120	0x9100	`kMfltRebootReason_BusFault`
Ibuserr	37121	0x9101
Preciserr	37122	0x9102
Impreciserr	37123	0x9103
Unstkerr	37124	0x9104
Stkerr	37125	0x9105
Lsperr	37126	0x9106
Bfarvalid	37127	0x9107

Memory Faults

Name	ID (decimal)	ID (hex)	MCU SDK enum
Mem Fault	37376	0x9200	`kMfltRebootReason_MemFault`
Iaccviol	37377	0x9201
Daccviol	37378	0x9202
Munstkerr	37379	0x9203
Mstkerr	37380	0x9204
Mlsperr	37381	0x9205
Mmarvalid	37382	0x9206

Usage Faults

Name	ID (decimal)	ID (hex)	MCU SDK enum
Usage Fault	37632	0x9300	`kMfltRebootReason_UsageFault`
Undefinstr	37633	0x9301
Invstate	37634	0x9302
Invpc	37635	0x9303
Nocp	37636	0x9304
Unaligned	37637	0x9305
Divbyzero	37638	0x9306

Misc.

Name	ID (decimal)	ID (hex)	MCU SDK enum	Notes
Hard Fault	37888	0x9400	`kMfltRebootReason_HardFault`
Lockup	37889	0x9401	`kMfltRebootReason_Lockup`	A reset which is triggered when the processor faults while already executing from a fault handler.

Expected Reboot Reasons
Unexpected Reboot Reasons
ARM-specific Error Reboot Reasons