IMX8 booting from wrong switch configuration

[sparro12]

On both our IMX8 Mini EVKs, the board is being configured for SD using the dip switches. However, when running minicom and viewing the output, the board is trying to boot from the MMC which is causing a failure. Any ideas as to why?

[joanxie]

what detailed error message do you get? do you mean you download images to the SD card, but the board boot up from EMMC? pls share more detailed information about your issue

[sparro12]

We build the yocto image, both the full and multimedia version, then run:

sudo dd if=imx-image-full-imx8mmevk-<TIMESTAMP>.rootfs.wic of=/dev/sdb bs=1M conv=fsync ;sync

This seems to work correctly. From there we verify that the SD card has been partioned into boot and root. Then, the card is inserted into the board, the board is plugged in to the computer through usb, and the board is booted up while minicom is running.

The below images show the configuration of our EVK along with the error message. You can see it's configured for SD from the DIP switches point of view. However, the error message suggests that it is looking for the eMMC rather than the SD card.

[joanxie]

did you try the demo images? or download your own built images to the emmc?  since you use nxp board, I suggest that you use demo images firstly, to confirm if your own built image has issue or not

[sparro12]

The way we know it is not the image is that we built the multimedia image, but the full image was built by a third-party company who was able to get it working on their IMX8 Mini EVK. So, it does not appear to be the image. There must be something else at play here.

[joanxie]

I use uuu tool to download images to sd card successfully, maybe you can test gain,

"uuu.exe -b sd_all <uboot image> <wic image>", then boot up from microSD card

[sparro12]

We tried UUU earlier, and got the same error. It seems that the image in both cases is working. The boot process appears to be the source of error.

[joanxie]

I need to know how to reproduce this on nxp mx8mm evk board, you use nxp imx8mm evk board, right? don't change anything, then use the images you build? if yes, did you try to build this image to the emmc? does it work?

[sparro12]

We are now using the Windows UUU bootloader and have found that to be reliable way.

For future users, we clone this repo: https://github.com/NXPmicro/mfgtools.

From there, you build the project UUU under the msvc folder using something like Visual Studio 2019. 

You can then run the 2 commands shown in the image. One is to check for connected USB devices and the other is to flash the image to the eMMC.

For this, you need to have 3 cables plugged in. The power USB-C, the debug micro-USB to USB-A connected to your computer, and the other USB-C cable to USB-A connected to your computer. The device should be put in serial downloader mode to flash the image/run the commands in the photo. Once, the flash is complete, the EVK should be shutoff, and the DIP switches should be changed to eMMC mode. From there, open Tera Term, choose the COM port along with the Baud rate of 115200,, and turn on the EVK. There should be a printout of the bootup sequence.