Approved version. Approved on: 16:49, 24 January 2023
- Last edited 4 months ago ago
How to diagnose a boot failure
The blue and red LEDs on STM32 MPU boards are used to notify the user in case of boot failure during the boot chain execution and at runtime.
2 Description and debug
The statuses of blue and red LEDs allow to see at which stage the execution failed: the diagram below shows how each boot component uses these LEDs while the table gives more information on the way to interpret the LED statuses when the boot fails. Among the boot components, the FSBL is TF-A and the SSBL is U-Boot, as explained in the boot chain overview.
|Blue LED||Red LED||System state||Action|
|Off||Blinking||The execution failed during ROM code execution||Check that:|
|On||Blinking||The execution failed during the second stage bootloader (SSBL)||See U-Boot - How to debug to investigate the failure|
|Off||Off||The execution may have failed:
|Off or on||Off||The execution may have failed during Linux® kernel execution between two heartbeat pulses (blue LED): a fatal error leading to a kernel panic might have occurred...||See Dmesg and Linux kernel log to investigate the failure|
|Blinking||Off||Your platform is alive||Enjoy !|