BSP 3.0.1  u-boot env.

Rev.A, Rev.B, Rev.C

=> setenv bootcmd 'fatload mmc 0:1 0x48080000 Image; fatload mmc 0:1 0x48000000 Image-r8a774c0-ek874-revc.dtb; booti 0x48080000 - 0x48000000'
=> setenv bootargs 'root=/dev/mmcblk0p2 rootwait ro'
=> saveenv
=> reset


Rev.D, Rev.E


=> setenv bootcmd 'fatload mmc 0:1 0x48080000 Image; fatload mmc 0:1 0x48000000 Image-r8a774c0-ek874.dtb; booti 0x48080000 - 0x48000000'
=> setenv bootargs 'root=/dev/mmcblk0p2 rootwait ro'
=> saveenv
=> reset


see also.

https://www.si-linux.co.jp/catwiki/index.php?CAT874_yocto_v3.0.1