IMX6ull : Serial download mode issue with mmc0

[HarshilSoni434]

Hello There,

Hope you are doing well.

We are using imx6ull based NXP Dev kit.

We have got one issue regarding boot-config pin for serial download mode.

Issue :

After setting the serial download mode boot-pin setting ,

if SD-card with flashed image is connected on MMC0 (SD1 lines) based connector then it is booting from SD card instead of going in serial download mode.

if That SD-card is not connected then and then only it is going into serial download mode.

Note :

• This issue is not with MMC1 (SD2 lines).

[Rita_Wang]

Are you using the NXP reference board?

[rudi_cyber]

It is a simple reason. 

The usdhc1 is SD/MMC manufacture mode interface. 

Before i.MX6ULL goes to serial download mode, it will check the SD/MMC manufacture mode interface first. 

It is a clear scenario in i.MX6ULL reference manual.

[HarshilSoni434]

Hello rudi ,

Thank you for your quick response ,

So can you suggest any solution for how can we disable it using efuse bits.?

if you have any documentation OR example then please let us know.

Thanks and Regards

[rudi_cyber · Accepted solution]

It is OCOTP_CFG6(OTP Bank 0, word 7) bit 3.
You can use fuse command in uboot to disable the SD/MMC manufacture mode.

But I suggest you could keep this usesful function for recovery or mass production.