IMX6UL burn eFuses from JTAG

[alubeiro]

Hi all,

I am working with MCIMX6UL-EVK and i want to burn an eFuse, specifically "UART Serial Download" which is 0x470[4].

I connect with the board via JTAG and i am able to modify other registers however i can´t modify this eFuse.

Anybody knows if this is posible with JTAG? or may i do something before modifying the eFuse?

We can't load any zimage or app because we can't make USB work, due to some issues we have with UART. The target of burning this eFuse is to disable uart detection so the USB is the first option in serial downloader mode. Then, i belive the PC will detect the board as HID unit.

Please any help will be apreciated.

Thanks and best regards

[Yuri]

Hello,

   You may try to download U-boot via JTAG and use it to burn the fuse.

Have a great day,
Yuri

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[alubeiro]

Hello Yuri,

The u-boot files we got, are the ones that are into Mfgtool and they are ".imx" data files. Our JTAG "J-Link base" from Segger supports .mot, .srec, .s19, .s, .hex, .bin data files, so how can we do this?

I know that .imx data file includes a IVT header for the boot ROM to identify the u-boot's location & function etc...so i wonder how to load one of the above data files format.

Then once the u-boot is downloaded, how can an e-fuse be burned?

We are new in linux and therefore we are having a hard time making it works, so please be patient and don't spare details

Thanks and best regards

[Yuri]

Hello,

1.

You may load and run the U-boot.imx as binary file, using information

of Table 8-26 (IVT Format) of the i.MX6UL RM. IVT is located in the beginning

of the file.
boot data (Absolute address of the Boot Data) - address to load

entry  (Absolute address of the first instruction to execute from the image) - start / run address.

2.

Program the fuse values using the “fuse” command, available in i.MX U-Boot.

U_boot> fuse prog <bank> <word> <value>

The <bank> and <word> values are sourced from the Fuse Map.

Regards,

Yuri.