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imx7 fuses in production

Question asked by Ruben Schwarz on Jul 4, 2017
Latest reply on Jul 4, 2017 by igorpadykov

Hi,

 

we are currently developing an imx7 based custom board.

 

Following fuses should be burned (from ucl2.xml):

<CMD state="Updater" type="push" body="$ echo %hwtype% > /sys/fsl_otp/HW_OCOTP_GP10">write hwtype %hwtype% to HW_OCOTP_GP10 fuse bank</CMD>
<CMD state="Updater" type="push" body="$ echo %hwrev%00 > /sys/fsl_otp/HW_OCOTP_GP10">write hwrev %hwrev%00 to HW_OCOTP_GP10 fuse bank</CMD>
<CMD state="Updater" type="push" body="$ echo %serialnumber%0000 > /sys/fsl_otp/HW_OCOTP_GP10">write serialnumber %serialnumber%0000 to HW_OCOTP_GP10 fuse bank</CMD>

<CMD state="Updater" type="push" body="$ echo 0x10002067 > /sys/fsl_otp/HW_OCOTP_BOOT_CFG0">burn boot fuses</CMD>

 

as you can see we want to burn the boot fuses and general purpose fuses.

 

Best would be if we can use MfG-Tool to burn all fuses.

 

But now we get 2 Problems:

 

1. Is there a recommended way how to customize each board? The serialnumber must be individual on each board. Do we need some scripting around mfg-tool to get this working?

 

2. Burning the boot fuses from MFG-Tool doesn't work. Fuses are untouched after reboot. Do we need any further steps (lock, etc) before burning the boot fuses? Is it possible to burn boot fuses via MFG-Tool? During development we are burning the fuses from u-boot but we have no idea how to integrate this into MFG-Workflow.

 

Does anybody have recommendations how to burn the fuses on production? Anybody here who already has an imx7-Board in production and give any hints where to search for a solution?

 

Thanks in advance and best regards

Ruben

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