Add OpenWrt arm64 build

.travis.yml

@@ -39,6 +39,14 @@ matrix:
              use_allocator="none" use_allocator_shim=false
              custom_toolchain="//build/toolchain/linux:clang_x64_openwrt"'
            OPENWRT_FLAGS='arch=x86_64 release=19.07.1 gcc_ver=7.5.0 target=x86 subtarget=64'
+    - name: "openwrt-arm64"
+      os: linux
+      dist: bionic
+      env: EXTRA_FLAGS='
+             target_cpu="arm64"
+             use_allocator="none" use_allocator_shim=false
+             custom_toolchain="//build/toolchain/linux:clang_arm64_openwrt"'
+           OPENWRT_FLAGS='arch=aarch64 release=19.07.1 gcc_ver=7.5.0 target=armvirt subtarget=64'
     - name: "osx"
       os: osx
       osx_image: xcode10.2

src/build/toolchain/linux/BUILD.gn

@@ -29,6 +29,16 @@ clang_toolchain("clang_arm64") {
   }
 }
 
+clang_toolchain("clang_arm64_openwrt") {
+  extra_cppflags = "--target=aarch64-openwrt-linux-musl -D_LIBCPP_HAS_MUSL_LIBC -D__UCLIBC__"
+  extra_ldflags = "--target=aarch64-openwrt-linux-musl"
+  toolprefix = "aarch64-linux-gnu-"
+  toolchain_args = {
+    current_cpu = "arm64"
+    current_os = "linux"
+  }
+}
+
 gcc_toolchain("arm64") {
   toolprefix = "aarch64-linux-gnu-"
 

src/get-openwrt.sh

@@ -23,8 +23,8 @@ for flag in ALL_NONSHARED ALL_KMODS ALL SIGNED_PACKAGES; do
 done
 make oldconfig
 make
-full_root=staging_dir/toolchain-${arch}_gcc-${gcc_ver}_musl
-cp -r staging_dir/target-${arch}_musl/usr $full_root
+full_root=staging_dir/toolchain-*_gcc-${gcc_ver}_musl
+cp -r staging_dir/target-*_musl/usr $full_root
 echo '
 ./include
 ./lib/*.o