i.mx6 burning OCOTP_OTPMK[0-7]

[zc_tee]

Dear all,

I am trying to write a bash script to burn the OCOTP_OTPMK[0-7] registers.

However, i find out that I am only able to write one OTPMK at a time. Writing the 2nd OTPMK will result in endless loop in the ssh window. Machine is still operateable at this time. After i reboot, i can then write the 2nd OTPMK register.

I need to reboot everytime on writing one OTPMK register. Is it the norm behaviour? If not, may i know is there anything wrong with my procedure?

Below is my script on writing the SRK and OTPMK register

#!/bin/bash

echo "YOU ARE GOING TO BURN THE E-FUSE!"

echo -n "THIS ACTION IS NOT REVERSIBLE! PLEASE CONFIRM [y/n]:"

read confirm

if [ "$confirm" = "y" ]; then

  echo Burning SRK...

  cd /sys/fsl_otp

  echo 0xxxxxxxxx > HW_OCOTP_SRK0

  echo 0xxxxxxxxx > HW_OCOTP_SRK1

  echo 0xxxxxxxxx > HW_OCOTP_SRK2

  echo 0xxxxxxxxx > HW_OCOTP_SRK3

  echo 0xxxxxxxxx > HW_OCOTP_SRK4

  echo 0xxxxxxxxx > HW_OCOTP_SRK5

  echo 0xxxxxxxxx > HW_OCOTP_SRK6

  echo 0xxxxxxxxx > HW_OCOTP_SRK7

  echo Burning OTP Fuse 1...

  echo 0x975b69a7 > HW_OCOTP_OTPMK0

  sleep 1

  echo Burning OTP fuse 2...

  echo 0xafae0b5d > HW_OCOTP_OTPMK1

  sleep 1

  echo Burning OTP fuse 3...

  echo 0x6f780499 > HW_OCOTP_OTPMK2

  sleep 1

  echo Burning OTP fuse 4...

  echo 0x3dda7a47 > HW_OCOTP_OTPMK3

  sleep 1

  echo Burning OTP fuse 5...

  echo 0x76fcba3c > HW_OCOTP_OTPMK4

  sleep 1

  echo Burning OTP fuse 6

  echo 0x6d5c9ef6 > HW_OCOTP_OTPMK5

  sleep 1

  echo Burning OTP fuse 7...

  echo 0xb166b40a > HW_OCOTP_OTPMK6

  sleep 1

  echo Burning OTP fuse 8...

  echo 0x8f449c5d > HW_OCOTP_OTPMK7

  sleep 1

  echo Enabling HAB...

  echo 0x00040000 > HW_OCOTP_MEM0

  echo 0x02 > HW_OCOTP_CFG5

  echo -n "Done. Press [enter] to reboot"

  read systemReboot

  echo system reboot

  reboot

else

  echo Aborted.

fi

Thank you.

Regards,

Tee

[Yuri]

Hello,

  Strictly speaking, the OTP may be burned once. As for the OTPMK burning  :

"This step is only required for preproduction parts where the fuses that are

normally programmed by Freescale are not programmed. On production

parts, the OTPMK are burned by Freescale prior to shipping the device."

Have a great day,
Yuri

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[zc_tee]

Hi Yuri,

Thanks for reply.

I am refering to the "i.MX6 Linux High Assurance Boot (HAB) User's Guide" (document number: IMX6HABUG) on this step of burning the OTPMK.

The information on burning this OTPMK is at page 9. Could you please advice whether i should burn the OTPMK?

Regards,

Tee

[Yuri · Accepted solution]

  Hardly usual customers can have preproduction i.MX6 parts without OTPMK burned.

I expect You do not need to burn it.

Regards,

Yuri

[zc_tee]

Hi Yuri,

I tested and it can be done without burning the OTPMK. Thanks!

[zc_tee]

Hi Yuri,

Thanks. I will try it out.

Regards,Tee