you can load them from u-boot console via tftp
setenv fdtaddr 0x83000000
setenv loadaddr 0x82000000
setenv bootfile zImage-cm-t335
setenv fdtfile am335x-cm-t335.dtb
tftp ${loadaddr} ${bootfile} && tftp ${fdtaddr} ${fdtfile}
bootz ${loadaddr} - ${fdtaddr}