i.MX Processorsのトピックburn fuses

burn fuses

sapirbuz — Tue, 21 Mar 2023 16:22:31 GMT

Hi,

How can we burn the fuses without an external flash on our board?

Can we use the internal ROM to do it?

sapirbuz_0-1679415733546.png

Re: burn fuses

JorgeCas — Tue, 21 Mar 2023 18:37:09 GMT

Hello,

On the i.MX8 and i.MX8x families the OTP memory is part of the security subsystem and is controlled by the SCU and SECO only. Please refer to this blog post about how users can read and write eFuses.

Understanding how to burn eFuses on i.MX8 and i.MX8x families.

Best regards.

Re: burn fuses

sapirbuz — Wed, 22 Mar 2023 10:08:51 GMT

Sorry, but i still don't understand if it is possible to burn fuses without an external flash, and how to do it in case it is possible

Re: burn fuses

JorgeCas — Wed, 22 Mar 2023 17:20:50 GMT

Hello,

Yes, you can burn fuses internally using U-boot, once the board is flashed you can use U-boot commands to read/write efuses using the SCFW API functions that are specified on the blog that is on the past answer.

Best regards.

Re: burn fuses

sapirbuz — Wed, 22 Mar 2023 17:41:36 GMT

What do you mean by "when the board is flashed"?

Re: burn fuses

JorgeCas — Wed, 22 Mar 2023 17:48:52 GMT

Hello,

It means that you have an image flashed on the board and it is able to boot.

Best regards.

Re: burn fuses

sapirbuz — Wed, 22 Mar 2023 18:49:34 GMT

If I have an image flashed on the board, it means that I have an external flash on the board, right?

But the external flash wasn't enabled (because we need to burn the fuses first) so it is like we don't have an external flash on the board.

How can we burn the fuses without an external flash on our board and we don't have an image flashed on the board?

Re: burn fuses

JorgeCas — Thu, 23 Mar 2023 18:07:29 GMT

Hello,

Got it, it that case it is not possible, you need to flash the MPU to burn efuses.

Best regards.

Re: burn fuses

sapirbuz — Sat, 25 Mar 2023 12:04:34 GMT

You are wrong.

It is possible using the LPSPI NOR/EEPROM.

After setting the "Boot Device" to "LPSPI NOR/EEPROM" , we succeed to burn the fuses.