topic Re: i.mx6 burning OCOTP_OTPMK[0-7] in i.MX Processors

i.mx6 burning OCOTP_OTPMK[0-7]

zc_tee — Mon, 28 Dec 2015 03:05:26 GMT

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.

Thank you.

Regards,

Tee

Re: i.mx6 burning OCOTP_OTPMK[0-7]

Yuri — Mon, 28 Dec 2015 06:05:54 GMT

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

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Re: i.mx6 burning OCOTP_OTPMK[0-7]

zc_tee — Mon, 28 Dec 2015 06:20:58 GMT

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

Re: i.mx6 burning OCOTP_OTPMK[0-7]

Yuri — Mon, 28 Dec 2015 06:51:23 GMT

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

I expect You do not need to burn it.

Regards,

Yuri

Re: i.mx6 burning OCOTP_OTPMK[0-7]

zc_tee — Mon, 28 Dec 2015 06:54:04 GMT

Hi Yuri,

Thanks. I will try it out.

Regards,Tee

Re: i.mx6 burning OCOTP_OTPMK[0-7]

zc_tee — Wed, 30 Dec 2015 08:36:52 GMT

Hi Yuri,

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