Index: Makefile
===================================================================
--- Makefile
+++ Makefile
@@ -514,12 +514,13 @@
 .endfor
 
 .if defined(USE_GCC_TOOLCHAINS)
-TOOLCHAINS_amd64=	amd64-gcc6
-TOOLCHAINS_arm64=	aarch64-gcc6
-TOOLCHAINS_i386=	i386-gcc6
-TOOLCHAINS_mips=	mips-gcc6
-TOOLCHAINS_powerpc=	powerpc-gcc6 powerpc64-gcc6
-TOOLCHAIN_powerpc64=	powerpc64-gcc6
+TOOLCHAINS_amd64=	amd64-gcc9
+TOOLCHAINS_arm64=	aarch64-gcc9
+TOOLCHAINS_i386=	i386-gcc9
+TOOLCHAINS_mips=	mips-gcc9
+TOOLCHAINS_powerpc=	powerpc-gcc9 powerpc64-gcc9
+TOOLCHAIN_powerpc64=	powerpc64-gcc9
+TOOLCHAINS_riscv=	riscv64-gcc9
 .endif
 
 # If a target is using an external toolchain, set MAKE_PARAMS to enable use