How to diagnose a boot failure

Stable: 06.11.2020 - 16:10 / Revision: 06.11.2020 - 16:04

I am here to prevent the first-page-empty bug!

1 Introduction

The blue and red LEDs on STM32MP15 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 can be TF-A or U-Boot SPL and the SSBL is U-Boot, as explained in the boot chain overview.

How to diagnose a boot failure.png


Blue LED Red LED System state Action
Off Blinking The execution failed during ROM code execution Check that:
  • your microSD card is properly inserted in the board
  • the boot pins configuration selects the boot device
  • your boot memory was well programmed with STM32CubeProgrammer
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:
  1. In FSBL execution
  2. After the SSBL execution but before the heartbeat (blue LED) started
  1. See TF-A - How to debug to investigate the failure
  2. See U-Boot - How to debug and how to trace and debug to investigate the failure
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 !


Light-emitting diode

First stage boot loader

Trusted firmware for Arm® Cortex®-A

Das U-Boot -- the universal boot loader (see U-Boot)

Secondary program loader, Also known as U-Boot SPL

Second stage boot loader

Linux® is a registered trademark of Linus Torvalds.

IMPORTANT NOTICE – READ CAREFULLY
STMicroelectronics NV and its subsidiaries ("ST") reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order acknowledgment.

Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or the design of purchasers’ products.

No license, express or implied, to any intellectual property right is granted by ST herein.

Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product.

ST and the ST logo are trademarks of ST. For additional information about ST trademarks, refer to www.st.com/trademarks. All other product or service names are the property of their respective owners.

Information in this document supersedes and replaces information previously supplied in any prior versions of this document.
© 2024 STMicroelectronics – All rights reserved