BELK-TN-011: Lock OTP Areas

Info Box Applies to Bora Applies to BORA Xpress

This technical note was validated against specific versions of hardware and software. What is described here may not work with other versions.

History

Version	Date	Notes
1.0.0	Sep 2020	First release

Introduction

As decribed on ConfigID management page, these informations are stored inside a general purpose OTP area of the SoC.

This technical note shows how to fix lock this OTP area on BORA systems running BSP versions older than BELK/BXELK-4.1.2

ConfigID programming

All Bora SOMs are shipped with ConfgID and UniqueID programmed and locked. The OTP lock ensure that nobody can change this data (unattempted code execution, etc).

It is possibile to execute these operations only using the devel versions of u-boot with the following commands:

configid som_configid <16 byte code>
configid som_uniqueid <32 byte code>
configid som_lock 0

Older BSP issue

In older BSP, due to a u-boot limitation, this OTP area is not really locked and therefore it should be possible to overwrite its value, with possible identification errors during updates.

Starting from the BELK/BXELK-4.1.2 release this issue have been solved.

Lock OTP area

It is suggested to update the systems running BSP releases older then BELK 4.1.2 performing the following steps:

• program on internal storage or alternatively boot from uSD using the u-boot devel version belk-4.1.2
  • devel version, for SD, are: belk-4.1.2_bora_mmc_devel_boot.bin and belk-4.1.2_bora_mmc_devel_u-boot.img
  • u-boot can be downloaded from our mirror server
  • u-boot 4.1.2 gives access to the OTP lock commands
• run the command configid som_lock 0
• program your u-boot release version to restore the normal operations (this is not required if previous operations have been executed using an external boot from SD)