Thanks
These tftp commands are not necessary.
I assume you have put these images in the second partition of SD card, you could load images from SD card as the following.
=> load mmc 0:2 0xa0000000 Image
=> load mmc 0:2 0xb0000000 rootfs_lsdk2108_buildroot_tiny_arm64.ext2.gz.u-boot
=> load mmc 0:2 0xc0000000 fsl-ls1046a-rdb-sdk.dtb
=> booti 0xa0000000 0xb0000000 0xc0000000
Please run the following command to get image rootfs_lsdk2108_buildroot_tiny_arm64.ext2.gz in build/images folder.
$ flex-builder -i mkrfs -r buildroot:tiny
The run the following command to generate rootfs_lsdk2108_buildroot_tiny_arm64.ext2.gz.u-boot.
$ mkimage -A arm -O linux -T ramdisk -C gzip -n rootfs_lsdk2108_buildroot_tiny_arm64 -d rootfs_lsdk2108_buildroot_tiny_arm64.ext2.gz rootfs_lsdk2108_buildroot_tiny_arm64.ext2.gz.u-boot
On the target board, run the following commands.
=> tftp 0xa0000000 b25805/ls1046ardb/Image
=> tftp 0xb0000000 b25805/ls1046ardb/rootfs_lsdk2108_buildroot_tiny_arm64.ext2.gz.u-boot
=> tftp 0xc0000000 b25805/ls1046ardb/fsl-ls1046a-rdb-sdk.dtb
=> booti 0xa0000000 0xb0000000 0xc0000000