buildroot/boot/riscv-pk/Config.in

comment "riscv-pk needs a Linux kernel to be built"
	depends on BR2_riscv
	depends on !BR2_LINUX_KERNEL

config BR2_TARGET_RISCV_PK
	bool "riscv-pk"
	depends on BR2_riscv
	depends on BR2_LINUX_KERNEL
	help
	  The RISC-V Proxy Kernel (pk) package contains the Berkeley
	  Boot Loader (BBL) which has been designed to boot a Linux
	  kernel on a RISC-V processor.

	  https://github.com/riscv/riscv-pk.git