Building U-boot for CM5 generates error

When I try to build u-boot for CM5 I get the following error:

./bsp --no-prepare-source u-boot rknext radxa-cm5-io

***
*** Can't find default configuration "arch/../configs/radxa-cm5-io-rk3588s_defconfig"!
***
make[1]: *** [scripts/kconfig/Makefile:96: radxa-cm5-io-rk3588s_defconfig] Error 1
make: *** [Makefile:577: radxa-cm5-io-rk3588s_defconfig] Error 2

I guess building u-boot for CM5 has not been implemented yet?