Always boot from SD

[joseluiszabalza]

Hello

 I have a custom board with iMX6ULL with switches for boot configuration.

The problem is that the board always boot from SD and never from NAND no matter the switch positions.

The NAND-Flash can be written from u-boot and Linux.

I checked the tracks configuring the pad as GPIO, so the routing is correct.

The fuses are not burning

root@imx6ull:~# cat /sys/fsl_otp/HW_OCOTP_CFG4
0x0
root@imx6ull:~# cat /sys/fsl_otp/HW_OCOTP_CFG5
0x0

Is there any explanation for this behavior?

[Yuri]

Hello,

   On the "BootMode.png" figure only BOOT_CFG[1] is shown / used.

Hardware Development Guide for the i.MX 6ULL, Rev. 0, 08/2016 recommends:

"The BOOT_CFG signals are required for proper functionality and operation and

should not be left floating".

https://www.nxp.com/docs/en/user-guide/IMX6ULLHDG.pdf 

  Customers can run the DDR Stress tool, which shows at start real boot configuration.

https://community.nxp.com/docs/DOC-105652 

Have a great day,

Yuri

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[joseluiszabalza]

Thanks Yuri.

The DDR Stress Test Tool tell me that the boot config is ok.

The problem was a bad flashed u-boot and the board go into SD/MMC manufacture mode.

You can see 8.12 SD/MMC manufacture mode in Reference Manual.

Best regards