Add rust env to rust image switch.sh

Updated build target configuration for Rust.

Author: Eeems

rust/Dockerfile

@@ -12,8 +12,8 @@ RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y -q \
 # Add rust binaries to PATH
 ENV PATH="$PATH:/root/.cargo/bin"
 
-# Set default build target to armv7
-ENV CARGO_BUILD_TARGET="armv7-unknown-linux-gnueabihf"
-
 # Target reMarkable architecture by default
 COPY config /root/.cargo/config
+
+RUN echo 'export CARGO_BUILD_TARGET="aarch64-unknown-linux-gnu"' >> /opt/x-tools/switch-aarch64.sh \
+    && echo 'export CARGO_BUILD_TARGET="armv7-unknown-linux-gnueabihf"' >> /opt/x-tools/switch-arm.sh