Index: lang/rust/Makefile
===================================================================
--- lang/rust/Makefile	(revision 545082)
+++ lang/rust/Makefile	(working copy)
@@ -47,12 +47,14 @@
 
 CONFLICTS_INSTALL?=	rust-nightly
 
-OPTIONS_DEFINE=		DOCS GDB SOURCES WASM
-OPTIONS_DEFAULT=	SOURCES WASM
+OPTIONS_DEFINE=		DOCS GDB SOURCES WASM AARCH64 RISCV64
+OPTIONS_DEFAULT=	SOURCES WASM AARCH64 RISCV64
 
 GDB_DESC=	Install ports gdb (necessary for debugging rust programs)
 SOURCES_DESC=	Install source files
 WASM_DESC=	Build the WebAssembly target (wasm32-unknown-unknown)
+AARCH64_DESC=	Build the AArch64 target (aarch64-unknown-none)
+RISCV64_DESC=	Build the RISC-V 64 target (riscv64gc-unknown-none-elf)
 
 DOCS_VARS=		_RUST_BUILD_DOCS=true
 DOCS_VARS_OFF=		_RUST_BUILD_DOCS=false
@@ -61,6 +63,8 @@
 WASM_VARS=		_RUST_BUILD_WASM=true \
 			_RUST_TARGETS+=wasm32-unknown-unknown
 WASM_VARS_OFF=		_RUST_BUILD_WASM=false
+AARCH64_VARS=		_RUST_TARGETS+=aarch64-unknown-none
+RISCV64_VARS=		_RUST_TARGETS+=riscv64gc-unknown-none-elf
 
 # See WRKSRC/src/stage0.txt for the date and version values.
 BOOTSTRAPS_DATE?=		2020-06-18