Update travis

.travis.yml

@@ -2,13 +2,11 @@ sudo: required
 
 language: rust
 
-rust: nightly-2018-06-25
+rust: nightly-2018-08-03
 
 cache:
   cargo: true
 
-services: docker
-
 addons:
   apt:
     packages:
@@ -20,18 +18,19 @@ env:
     - ARCH="riscv32"
     - ARCH="x86_64"
 
-before_script:
-  - if [ $ARCH = x86_64 ]; then
-    rustup component add rust-src &&
-    (test -x $HOME/.cargo/bin/cargo-install-update || cargo install cargo-update) &&
-    (test -x $HOME/.cargo/bin/xargo || cargo install xargo) &&
-    cargo install-update -a;
+install:
+  - if [ $ARCH = riscv32 ]; then
+    export FILE="riscv64-unknown-elf-gcc-2018.07.0-x86_64-linux-ubuntu14";
+    wget https://static.dev.sifive.com/dev-tools/$FILE.tar.gz;
+    tar xf $FILE.tar.gz;
+    export PATH=$PATH:$PWD/$FILE/bin;
     fi
 
+before_script:
+  - rustup component add rust-src
+  - (test -x $HOME/.cargo/bin/cargo-install-update || cargo install cargo-update)
+  - (test -x $HOME/.cargo/bin/cargo-xbuild || cargo install cargo-xbuild)
+  - cargo install-update -a
+
 script:
-  - if [ $ARCH = riscv32 ]; then
-      docker run -v $(pwd):$(pwd) -w $(pwd) wangrunji0408/riscv-rust
-        bash -c "cd kernel && make patch-core && make build arch=riscv32";
-    elif [ $ARCH = x86_64 ]; then
-      cd kernel && make build arch=x86_64;
-    fi
+  - cd kernel && make build arch=$ARCH