Add Rust Toolchain to build on aarch64 hosts

Signed-off-by: Sean Gilligan <sean@msgilligan.com>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>

toolchain.mk

@@ -4,6 +4,7 @@
 SHELL				= /bin/bash
 ROOT				?= $(CURDIR)/..
 TOOLCHAIN_ROOT 			?= $(ROOT)/toolchains
+RUST_TOOLCHAIN_PATH 		?= $(TOOLCHAIN_ROOT)/rust
 UNAME_M				:= $(shell uname -m)
 ARCH				?= arm
 
@@ -44,6 +45,16 @@ define build_toolchain
 	@touch $2/.done
 endef
 
+# Download the Rust toolchain
+define dl-rust-toolchain
+	@if [ ! -d "$(1)" ]; then \
+		mkdir -p $(1) && \
+		export RUSTUP_HOME=$(1)/.rustup && \
+		export CARGO_HOME=$(1)/.cargo && \
+		curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --no-modify-path; \
+	fi
+endef
+
 ifeq ($(UNAME_M),x86_64)
 ifeq ($(ARCH),arm)
 AARCH32_PATH 			?= $(TOOLCHAIN_ROOT)/aarch32
@@ -56,8 +67,6 @@ AARCH64_CROSS_COMPILE 		?= $(AARCH64_PATH)/bin/aarch64-linux-gnu-
 AARCH64_GCC_VERSION 		?= arm-gnu-toolchain-11.3.rel1-x86_64-aarch64-none-linux-gnu
 SRC_AARCH64_GCC 		?= https://developer.arm.com/-/media/Files/downloads/gnu/11.3.rel1/binrel/$(AARCH64_GCC_VERSION).tar.xz
 
-RUST_TOOLCHAIN_PATH 		?= $(TOOLCHAIN_ROOT)/rust
-
 .PHONY: toolchains
 toolchains: aarch32-toolchain aarch64-toolchain rust-toolchain
 
@@ -69,16 +78,6 @@ aarch32-toolchain:
 aarch64-toolchain:
 	$(call dltc,$(AARCH64_PATH),$(SRC_AARCH64_GCC),$(AARCH64_GCC_VERSION))
 
-# Download the Rust toolchain
-define dl-rust-toolchain
-	@if [ ! -d "$(1)" ]; then \
-		mkdir -p $(1) && \
-		export RUSTUP_HOME=$(1)/.rustup && \
-		export CARGO_HOME=$(1)/.cargo && \
-		curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --no-modify-path; \
-	fi
-endef
-
 .PHONY: rust-toolchain
 rust-toolchain:
 	$(call dl-rust-toolchain,$(RUST_TOOLCHAIN_PATH))
@@ -131,7 +130,7 @@ AARCH64_PATH 			?= $(TOOLCHAIN_ROOT)/aarch64
 AARCH64_CROSS_COMPILE 		?= $(AARCH64_PATH)/bin/aarch64-linux-
 
 .PHONY: toolchains
-toolchains: aarch32-toolchain $(AARCH64_PATH)/.done
+toolchains: aarch32-toolchain $(AARCH64_PATH)/.done rust-toolchain
 
 .PHONY: aarch32-toolchain
 aarch32-toolchain:
@@ -140,6 +139,10 @@ aarch32-toolchain:
 $(AARCH64_PATH)/.done:
 	$(call build_toolchain,aarch64,$(AARCH64_PATH),aarch64,gnu)
 
+.PHONY: rust-toolchain
+rust-toolchain:
+	$(call dl-rust-toolchain,$(RUST_TOOLCHAIN_PATH))
+
 else # $(UNAME_M) != x86_64 or $(UNAME_M) != aarch64
 AARCH32_PATH 			:= $(TOOLCHAIN_ROOT)/aarch32
 AARCH32_CROSS_COMPILE 		:= $(AARCH32_PATH)/bin/arm-linux-