u-boot/lib/rsa/Kconfig

config RSA
	bool "Use RSA Library"
	select RSA_FREESCALE_EXP if FSL_CAAM
	select RSA_SOFTWARE_EXP if !RSA_FREESCALE_EXP
	help
	  RSA support. This enables the RSA algorithm used for FIT image
	  verification in U-Boot.
	  See doc/uImage.FIT/signature.txt for more details.

if RSA
config RSA_SOFTWARE_EXP
	bool "Enable driver for RSA Modular Exponentiation in software"
	depends on DM && RSA
	help
	  Enables driver for modular exponentiation in software. This is a RSA
	  algorithm used in FIT image verification. It required RSA Key as
	  input.
	  See doc/uImage.FIT/signature.txt for more details.

config RSA_FREESCALE_EXP
	bool "Enable RSA Modular Exponentiation with FSL crypto accelerator"
	depends on DM && RSA && FSL_CAAM
	help
	Enables driver for RSA modular exponentiation using Freescale cryptographic
	accelerator - CAAM.

endif