Why sdcard image supplied by Getting Started guide does not boot, is UBoot in it?

[chris13]

I'm new to this community and I'm unable to boot my i.MX 8M Q EVK board from SD card.
Out of the box, with boot device switch in defualt position (0010) the board boots fine the android from eMMC.
However, I need to boot my own OS from SD. To learn how to do it I flash the Linux image that is referenced by the Getting Started guide, named:
fsl-image-qt5-validation-imx-xwayland-imx8mqevk.sdcard

onto my sdcard with a command:
$ sudo dd if=fsl-image-qt5-validation-imx-xwayland-imx8mqevk.sdcard of=/dev/sda bs=1M && sync
Then I verify that the image did flash correctly. Parted displays:

Disk /dev/sda: 126GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number Start End Size Type File system Flags
1 8389kB 75.5MB 67.1MB primary fat16 lba
2 75.5MB 2642MB 2567MB primary ext4

Then I mount the first FAT partition /dev/sda1 I see it is labeled: "Boot imx8mq" and has "Image" file + couple of ".bin" files and many "dtb" files. I assume these are Linux kernel + some drivers (?) + device tree files.

The second (ext4) partition labeled "2.6 G Volume" contains Linux file system.

I don't know where the bootloader "UBoot is though. Is it in 8MiB un-allocated space before /dev/sda1 (which starts at 8389kB)?
But confident that the above image is valid, I put the card into SD2 slot of the board, set the boot device switch to boot from SD2 (1100) and power on but the board seems to be dead. Nothing is going to HDMI display (that my monitor is attached to) nor to serial debug port that my computer and putty client is listening to.
What steps am I missing here? I still don't understand if the image fsl-image-qt5-validation-imx-xwayland-imx8mqevk.sdcard I have flashed onto my sdcard contains the bootloader (UBoot) and where?

Please help me to understand what's going on, thanks!

[chris13 · Accepted solution]

Indeed, I downloaded the latest version L5.4.24-2.1.0_images_MX8MQEVK, flashed the uboot & Linux image to the SD card in the board using:
>.\uuu  -b sd_all  imx-boot-imx8mqevk-sd.bin-flash_evk imx-image-full-imx8mqevk.wic
and now the board boots from SD card and the Linux demo is working.
So it was the case of an old SD image that could not work on my new revision of the board.
Thanks very much Rita for your help.

[Rita_Wang]

Good news it works. The old L4.9.88_2.0.0 is for MX8MQ REV B version board.

[chris13]

Thanks for your reply.
I have downloaded the BSP from this link: L4.9.88_2.0.0_MX8MQ 
The image name I downloaded is L4.9.88_2.0.0_images_MX8MQ.tar.gz and I extracted the .sdcard from there.
The revision number on the back of my board says: SCH-38820 REV A1.

I don't understand what uo mean by "UUU tool" (first time hearing this name), please point me out to it so that I learn about it. Have a nice weekend!

[Rita_Wang]

The uuu tool is the new version of MFGTOOL, from the Linux 4.14.98 we use the new tool UUU to download. A s you are using the SCH-38820 REV A1 recommend you to use the newer version BSP.Embedded Linux for i.MX Applications Processors | NXP 

[Rita_Wang]

What's your board version ?The  i.MX 8MQ EVK board have REV B3/B4/A version. And which version of BSP are you using?

For the SD boot up is different boot mode from emmc. You can use the UUU tool to download.