Please run the following command in build environment.
$ bitbake fsl-image-networking
Boot Linux with commands
=> tftp 0xa0000000 b25805/ls1043ardb/Image
=> tftp 0xb0000000 b25805/ls1043ardb/ fsl-image-networking-ls1043ardb.cpio.gz.u-boot
=> tftp 0xc0000000 b25805/ls1043ardb/fsl-ls1043a-rdb-usdpaa.dtb
=> booti 0xa0000000 0xb0000000 0xc0000000