Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM

[rodrigo_travess]

Hello,

At the AN4581 Application Note section 5.7 it is recommended to program the SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses to completely secure the device, but looking at both the IMX8MMRM and IMX8MMSRM, I wasn't able to find the exact location of those fuses (bank, word, bit). Where can I find this information?

Thank you!

[jxb4256]

Can you also share this with me, please? Why isn't this just posted in a public app note, or the reference manual or security reference manual? Security through obscurity is not security.

[stephanwächter]

We also want to disable JTAG on the imx8m-mini and I couldn't find any info of about it in Reference Manual, Rev. 2, 08/2019 Chapter 6.2 Fusemap. Could you also point me into the right direction.

Thank you!

[igorpadykov · Accepted solution]

Hi rodrigo_travess

additional info were sent via mail.

Best regards
igor

[jbruno79]

hi @igorpadykov,

I need information about the fuses for the imx8m mini. Could you be so kind to provide it to me? I need to disable the JTAG for security reasons.

Best regrads,

Julián

[johneubanks]

@igorpadykov could you also send me the info for the JTAG_HEO fuse?
Thanks!

[paul_geurts]

Could you make this email public information? Why is this information not listed in the security reference manual? For the i.MX8M Nano this is listed in the security reference manual. But I cannot know whether the Mini uses the same fuses.

Also, AN4581 also lists fuse DIR_BT_DIS to be of interest. But I cannot find any reference of it.