build scripts run a xargo build with a no_std target.

.travis.yml

@@ -8,4 +8,9 @@ rust:
  - nightly
 cache: cargo
 
+addons:
+  apt:
+    packages:
+    - jq
+
 script: bin/travis/script

bin/build_tc

@@ -11,6 +11,7 @@ export CARGO_TARGET_DIR="${REPO_DIR}/target/build_local/${TC}"
 
 set -x;
 
+rustup self update;
 rustup toolchain update ${TC};
 
 cd ${REPO_DIR}/framed;
@@ -23,6 +24,20 @@ if [[ "${TC}" == "nightly" ]]; then
     cargo +${TC} test -p framed --verbose --lib \
           --no-default-features --features=use_nightly;
 
+    # xargo arm build
+    rustup component add rust-src --toolchain ${TC};
+    xargo_latest=$(curl https://crates.io/api/v1/crates/xargo \
+                   | jq '.versions|sort_by(.created_at)|last|.num' -r);
+    if cargo +${TC} install --list | egrep --no-messages --quiet "xargo v${xargo_latest}"; then
+        echo "xargo version already latest."
+    else
+        cargo +${TC} install --verbose --force xargo;
+    fi
+
+    rustup run ${TC} xargo build --verbose --lib \
+        --target thumbv7em-none-eabihf \
+        --no-default-features --features=use_nightly;
+
     # doc tests require nightly
     cargo +${TC} test -p framed --verbose --doc \
           --features=use_nightly;