I have followed all the steps mentioned on the below link
MCIMX6ULL-EVK - Linux on ARM - eewiki
I didn't face any errors or warnings while folllowing those steps. Once I tried to boot from SD Card, U-boot is searching for uEnv.txt. After that, it is displaying Invalid Partition 4, Invalid Partition 5, Invalid Partition 6, Invalid Partition 7. And it is not starting the kernel.
I have gone through the same page for different boards and in some of them, SD card partition steps are having some additional steps and changes. Did I miss something here?
it seems there are some issue about your uEnv.txt, pls check if set the correct mmcblkx to your boot sd card, you also can hit any key when the board boot up, then you set the correct uboot parameter, then type the "run bootcmd", for how to set the uboot, you can refer to the linux user guide, I don't know what version you use, you can download the documents from link as below:
i.MX 6Quad SABRE Development Board | NXP
find "Supporting Information (11)", then find linux user guide.