Fix CMake Support and Enhance Newlib Targets

Fixes CMake support for all targets, ensuring support for C11, C++11, `try_run`, and more features. To do so, we've included tests with a CMake test suite that compiles for a bare-metal target, one that compiles against [re2](https://github.com/google/re2), and one using CMake's `try_run` (checking [CMAKE_CROSSCOMPILING_EMULATOR](https://cmake.org/cmake/help/latest/variable/CMAKE_CROSSCOMPILING_EMULATOR.html) is set for any cross-compiled targets).

CMake support for Android targets was fixed by providing a toolchain file that specifies the API level and the standalone toolchain path, and ensuring that compiler detection is forcibly disabled. For other targets, a default toolchain file is provided that ensures the correct system name, processor, cross-compiling emulator, binutils, and cross-compilers are used. For bare-metal (newlib) targets, this ensures that `try_compile` uses a static library rather than an executable to avoid requiring a linker script to detect if the compiler works.

This also adds a few minor changes for newlib targets:
- Adds C++ support to bare-metal newlib targets by installing `libstdc++-arm-none-eabi-newlib`.
- Updates `targets.toml` to specify that newlib targets do not have `std` support.
- Use the Cortex-M1 CPU for `thumbv6m-none-eabi` rather than the Cortex-M3 (an ARMv7-M CPU) for the Qemu runner.

Author: Alexhuszagh

.changes/1112.json

@@ -0,0 +1,11 @@
+[
+    {
+        "description": "fixed CMake support for Android and newlib targets.",
+        "type": "fixed",
+        "issues": [1110]
+    },
+    {
+        "description": "added C++ support for newlib targets.",
+        "type": "added"
+    }
+]

ci/test.sh

@@ -68,12 +68,10 @@ main() {
         retry cargo fetch
         # don't use xargo: should have native support just from rustc
         rustup toolchain add nightly
-        "${CROSS[@]}" build --lib --target "${TARGET}" ${CROSS_FLAGS}
+        cross_build --lib --target "${TARGET}"
         popd
 
         rm -rf "${td}"
-
-        return
     fi
 
     # `cross build` test for the other targets
@@ -83,7 +81,7 @@ main() {
         pushd "${td}"
         cargo init --lib --name foo .
         retry cargo fetch
-        "${CROSS[@]}" build --target "${TARGET}" ${CROSS_FLAGS}
+        cross_build --target "${TARGET}"
         popd
 
         rm -rf "${td}"
@@ -94,7 +92,7 @@ main() {
         # test that linking works
         cargo init --bin --name hello .
         retry cargo fetch
-        "${CROSS[@]}" build --target "${TARGET}" ${CROSS_FLAGS}
+        cross_build --target "${TARGET}"
         popd
 
         rm -rf "${td}"
@@ -166,18 +164,32 @@ main() {
 
     fi
 
-    # Test C++ support
+    # Test C++ support in a no_std context
     if (( ${CPP:-0} )); then
         td="$(mkcargotemp -d)"
 
+        git clone --depth 1 https://github.com/cross-rs/rust-cpp-accumulate "${td}"
+
+        pushd "${td}"
+        retry cargo fetch
+        cross_build --target "${TARGET}"
+        popd
+
+        rm -rf "${td}"
+    fi
+
+    # Test C++ support
+    if (( ${STD:-0} )) && (( ${CPP:-0} )); then
+        td="$(mkcargotemp -d)"
+
         git clone --depth 1 https://github.com/cross-rs/rust-cpp-hello-word "${td}"
 
         pushd "${td}"
         retry cargo fetch
         if (( ${RUN:-0} )); then
             cross_run --target "${TARGET}"
         else
-            "${CROSS[@]}" build --target "${TARGET}" ${CROSS_FLAGS}
+            cross_build --target "${TARGET}"
         fi
         popd
 
@@ -193,11 +205,44 @@ main() {
         cargo init --bin --name hello .
         retry cargo fetch
         RUSTFLAGS="-C target-feature=-crt-static" \
-            "${CROSS[@]}" build --target "${TARGET}" ${CROSS_FLAGS}
+            cross_build --target "${TARGET}"
         popd
 
         rm -rf "${td}"
     fi
+
+    # test cmake support
+    td="$(mkcargotemp -d)"
+
+    git clone \
+        --recursive \
+        --depth 1 \
+        https://github.com/cross-rs/rust-cmake-hello-world "${td}"
+
+    pushd "${td}"
+    retry cargo fetch
+    if [[ "${TARGET}" == "arm-linux-androideabi" ]]; then
+        # ARMv5te isn't supported anymore by Android, which produces missing
+        # symbol errors with re2 like `__libcpp_signed_lock_free`.
+        cross_run --target "${TARGET}" --features=tryrun
+    elif (( ${STD:-0} )) && (( ${RUN:-0} )) && (( ${CPP:-0} )); then
+        cross_run --target "${TARGET}" --features=re2,tryrun
+    elif (( ${STD:-0} )) && (( ${CPP:-0} )); then
+        cross_build --target "${TARGET}" --features=re2
+    elif (( ${STD:-0} )) && (( ${RUN:-0} )); then
+        cross_run --target "${TARGET}" --features=tryrun
+    elif (( ${STD:-0} )); then
+        cross_build --target "${TARGET}" --features=tryrun
+    else
+        cross_build --lib --target "${TARGET}"
+    fi
+    popd
+
+    rm -rf "${td}"
+}
+
+cross_build() {
+    "${CROSS[@]}" build "$@" ${CROSS_FLAGS}
 }
 
 cross_run() {

docker/Dockerfile.aarch64-linux-android

@@ -34,15 +34,18 @@ RUN /android-system.sh arm64
 
 ENV CROSS_TOOLCHAIN_PREFIX=aarch64-linux-android-
 ENV CROSS_SYSROOT=/android-ndk/sysroot
+ENV CROSS_ANDROID_SDK=$ANDROID_SDK
 COPY android-symlink.sh /
 RUN /android-symlink.sh aarch64 aarch64-linux-android
 
 COPY android-runner /
+COPY android.cmake /opt/toolchain.cmake
 
 # Libz is distributed in the android ndk, but for some unknown reason it is not
 # found in the build process of some crates, so we explicit set the DEP_Z_ROOT
+ENV CROSS_TARGET_RUNNER="/android-runner aarch64"
 ENV CARGO_TARGET_AARCH64_LINUX_ANDROID_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc \
-    CARGO_TARGET_AARCH64_LINUX_ANDROID_RUNNER="/android-runner aarch64" \
+    CARGO_TARGET_AARCH64_LINUX_ANDROID_RUNNER="$CROSS_TARGET_RUNNER" \
     AR_aarch64_linux_android="$CROSS_TOOLCHAIN_PREFIX"ar \
     AS_aarch64_linux_android="$CROSS_TOOLCHAIN_PREFIX"as \
     CC_aarch64_linux_android="$CROSS_TOOLCHAIN_PREFIX"gcc \
@@ -56,11 +59,16 @@ ENV CARGO_TARGET_AARCH64_LINUX_ANDROID_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc \
     SIZE_aarch64_linux_android="$CROSS_TOOLCHAIN_PREFIX"size \
     STRINGS_aarch64_linux_android="$CROSS_TOOLCHAIN_PREFIX"strings \
     STRIP_aarch64_linux_android="$CROSS_TOOLCHAIN_PREFIX"strip \
+    CMAKE_TOOLCHAIN_FILE_aarch64_linux_android=/opt/toolchain.cmake \
     BINDGEN_EXTRA_CLANG_ARGS_aarch64_linux_android="--sysroot=$CROSS_SYSROOT" \
     DEP_Z_INCLUDE="$CROSS_SYSROOT/usr/include"/ \
     RUST_TEST_THREADS=1 \
     HOME=/tmp/ \
     TMPDIR=/tmp/ \
     ANDROID_DATA=/ \
     ANDROID_DNS_MODE=local \
-    ANDROID_ROOT=/system
+    ANDROID_ROOT=/system \
+    CROSS_CMAKE_SYSTEM_NAME=Android \
+    CROSS_CMAKE_SYSTEM_PROCESSOR=aarch64 \
+    CROSS_CMAKE_CRT=android \
+    CROSS_CMAKE_OBJECT_FLAGS="-DANDROID -ffunction-sections -fdata-sections -fPIC"

docker/Dockerfile.aarch64-unknown-linux-gnu

@@ -29,15 +29,22 @@ COPY linux-image.sh /
 RUN /linux-image.sh aarch64
 
 COPY linux-runner base-runner.sh /
+COPY toolchain.cmake /opt/toolchain.cmake
 
 ENV CROSS_TOOLCHAIN_PREFIX=aarch64-linux-gnu-
 ENV CROSS_SYSROOT=/usr/aarch64-linux-gnu
+ENV CROSS_TARGET_RUNNER="/linux-runner aarch64"
 ENV CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc \
-    CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_RUNNER="/linux-runner aarch64" \
+    CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_RUNNER="$CROSS_TARGET_RUNNER" \
     AR_aarch64_unknown_linux_gnu="$CROSS_TOOLCHAIN_PREFIX"ar \
     CC_aarch64_unknown_linux_gnu="$CROSS_TOOLCHAIN_PREFIX"gcc \
     CXX_aarch64_unknown_linux_gnu="$CROSS_TOOLCHAIN_PREFIX"g++ \
+    CMAKE_TOOLCHAIN_FILE_aarch64_unknown_linux_gnu=/opt/toolchain.cmake \
     BINDGEN_EXTRA_CLANG_ARGS_aarch64_unknown_linux_gnu="--sysroot=$CROSS_SYSROOT" \
     QEMU_LD_PREFIX="$CROSS_SYSROOT" \
     RUST_TEST_THREADS=1 \
-    PKG_CONFIG_PATH="/usr/lib/aarch64-linux-gnu/pkgconfig/:${PKG_CONFIG_PATH}"
+    PKG_CONFIG_PATH="/usr/lib/aarch64-linux-gnu/pkgconfig/:${PKG_CONFIG_PATH}" \
+    CROSS_CMAKE_SYSTEM_NAME=Linux \
+    CROSS_CMAKE_SYSTEM_PROCESSOR=aarch64 \
+    CROSS_CMAKE_CRT=gnu \
+    CROSS_CMAKE_OBJECT_FLAGS="-ffunction-sections -fdata-sections -fPIC"

docker/Dockerfile.aarch64-unknown-linux-gnu.centos

@@ -30,13 +30,21 @@ COPY linux-runner base-runner.sh /
 COPY aarch64-linux-gnu-glibc.sh /
 RUN /aarch64-linux-gnu-glibc.sh
 
+COPY toolchain.cmake /opt/toolchain.cmake
+
 ENV CROSS_TOOLCHAIN_PREFIX=aarch64-linux-gnu-
 ENV CROSS_SYSROOT=/usr/aarch64-linux-gnu
+ENV CROSS_TARGET_RUNNER="/linux-runner aarch64"
 ENV CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc \
-    CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_RUNNER="/linux-runner aarch64" \
+    CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_RUNNER="$CROSS_TARGET_RUNNER" \
     AR_aarch64_unknown_linux_gnu="$CROSS_TOOLCHAIN_PREFIX"ar \
     CC_aarch64_unknown_linux_gnu="$CROSS_TOOLCHAIN_PREFIX"gcc \
     CXX_aarch64_unknown_linux_gnu="$CROSS_TOOLCHAIN_PREFIX"g++ \
+    CMAKE_TOOLCHAIN_FILE_aarch64_unknown_linux_gnu=/opt/toolchain.cmake \
     BINDGEN_EXTRA_CLANG_ARGS_aarch64_unknown_linux_gnu="--sysroot=$CROSS_SYSROOT" \
     QEMU_LD_PREFIX="$CROSS_SYSROOT" \
-    RUST_TEST_THREADS=1
+    RUST_TEST_THREADS=1 \
+    CROSS_CMAKE_SYSTEM_NAME=Linux \
+    CROSS_CMAKE_SYSTEM_PROCESSOR=aarch64 \
+    CROSS_CMAKE_CRT=gnu \
+    CROSS_CMAKE_OBJECT_FLAGS="-ffunction-sections -fdata-sections -fPIC"

docker/Dockerfile.aarch64-unknown-linux-musl

@@ -23,13 +23,20 @@ RUN /musl-symlink.sh $CROSS_SYSROOT aarch64
 
 COPY musl-gcc.sh /usr/bin/"$CROSS_TOOLCHAIN_PREFIX"gcc.sh
 COPY qemu-runner base-runner.sh /
+COPY toolchain.cmake /opt/toolchain.cmake
 
+ENV CROSS_TARGET_RUNNER="/qemu-runner aarch64"
 ENV CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc.sh \
-    CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_RUNNER="/qemu-runner aarch64" \
+    CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_RUNNER="$CROSS_TARGET_RUNNER" \
     AR_aarch64_unknown_linux_musl="$CROSS_TOOLCHAIN_PREFIX"ar \
     CC_aarch64_unknown_linux_musl="$CROSS_TOOLCHAIN_PREFIX"gcc \
     CXX_aarch64_unknown_linux_musl="$CROSS_TOOLCHAIN_PREFIX"g++ \
+    CMAKE_TOOLCHAIN_FILE_aarch64_unknown_linux_musl=/opt/toolchain.cmake \
     BINDGEN_EXTRA_CLANG_ARGS_aarch64_unknown_linux_musl="--sysroot=$CROSS_SYSROOT" \
     QEMU_LD_PREFIX="$CROSS_SYSROOT" \
     RUST_TEST_THREADS=1 \
+    CROSS_CMAKE_SYSTEM_NAME=Linux \
+    CROSS_CMAKE_SYSTEM_PROCESSOR=aarch64 \
+    CROSS_CMAKE_CRT=musl \
+    CROSS_CMAKE_OBJECT_FLAGS="-ffunction-sections -fdata-sections -fPIC" \
     CROSS_BUILTINS_PATCHED_MINOR_VERSION=48

docker/Dockerfile.arm-linux-androideabi

@@ -34,15 +34,18 @@ RUN /android-system.sh arm
 
 ENV CROSS_TOOLCHAIN_PREFIX=arm-linux-androideabi-
 ENV CROSS_SYSROOT=/android-ndk/sysroot
+ENV CROSS_ANDROID_SDK=$ANDROID_SDK
 COPY android-symlink.sh /
 RUN /android-symlink.sh arm arm-linux-androideabi
 
 COPY android-runner /
+COPY android.cmake /opt/toolchain.cmake
 
 # Libz is distributed in the android ndk, but for some unknown reason it is not
 # found in the build process of some crates, so we explicit set the DEP_Z_ROOT
+ENV CROSS_TARGET_RUNNER="/android-runner arm"
 ENV CARGO_TARGET_ARM_LINUX_ANDROIDEABI_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc \
-    CARGO_TARGET_ARM_LINUX_ANDROIDEABI_RUNNER="/android-runner arm" \
+    CARGO_TARGET_ARM_LINUX_ANDROIDEABI_RUNNER="$CROSS_TARGET_RUNNER" \
     AR_arm_linux_androideabi="$CROSS_TOOLCHAIN_PREFIX"ar \
     AS_arm_linux_androideabi="$CROSS_TOOLCHAIN_PREFIX"as \
     CC_arm_linux_androideabi="$CROSS_TOOLCHAIN_PREFIX"gcc \
@@ -56,11 +59,16 @@ ENV CARGO_TARGET_ARM_LINUX_ANDROIDEABI_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc \
     SIZE_arm_linux_androideabi="$CROSS_TOOLCHAIN_PREFIX"size \
     STRINGS_arm_linux_androideabi="$CROSS_TOOLCHAIN_PREFIX"strings \
     STRIP_arm_linux_androideabi="$CROSS_TOOLCHAIN_PREFIX"strip \
+    CMAKE_TOOLCHAIN_FILE_arm_linux_androideabi=/opt/toolchain.cmake \
     BINDGEN_EXTRA_CLANG_ARGS_arm_linux_androideabi="--sysroot=$CROSS_SYSROOT" \
     DEP_Z_INCLUDE="$CROSS_SYSROOT/usr/include/" \
     RUST_TEST_THREADS=1 \
     HOME=/tmp/ \
     TMPDIR=/tmp/ \
     ANDROID_DATA=/ \
     ANDROID_DNS_MODE=local \
-    ANDROID_ROOT=/system
+    ANDROID_ROOT=/system \
+    CROSS_CMAKE_SYSTEM_NAME=Android \
+    CROSS_CMAKE_SYSTEM_PROCESSOR=armv5te \
+    CROSS_CMAKE_CRT=android \
+    CROSS_CMAKE_OBJECT_FLAGS="--target=arm-linux-androideabi -DANDROID -ffunction-sections -fdata-sections -fPIC --target=arm-linux-androideabi"

docker/Dockerfile.arm-unknown-linux-gnueabi

@@ -23,15 +23,22 @@ COPY qemu.sh /
 RUN /qemu.sh arm
 
 COPY qemu-runner base-runner.sh /
+COPY toolchain.cmake /opt/toolchain.cmake
 
 ENV CROSS_TOOLCHAIN_PREFIX=arm-linux-gnueabi-
 ENV CROSS_SYSROOT=/usr/arm-linux-gnueabi
+ENV CROSS_TARGET_RUNNER="/qemu-runner arm"
 ENV CARGO_TARGET_ARM_UNKNOWN_LINUX_GNUEABI_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc \
-    CARGO_TARGET_ARM_UNKNOWN_LINUX_GNUEABI_RUNNER="/qemu-runner arm" \
+    CARGO_TARGET_ARM_UNKNOWN_LINUX_GNUEABI_RUNNER="$CROSS_TARGET_RUNNER" \
     AR_arm_unknown_linux_gnueabi="$CROSS_TOOLCHAIN_PREFIX"ar \
     CC_arm_unknown_linux_gnueabi="$CROSS_TOOLCHAIN_PREFIX"gcc \
     CXX_arm_unknown_linux_gnueabi="$CROSS_TOOLCHAIN_PREFIX"g++ \
+    CMAKE_TOOLCHAIN_FILE_arm_unknown_linux_gnueabi=/opt/toolchain.cmake \
     BINDGEN_EXTRA_CLANG_ARGS_arm_unknown_linux_gnueabi="--sysroot=$CROSS_SYSROOT" \
     QEMU_LD_PREFIX="$CROSS_SYSROOT" \
     RUST_TEST_THREADS=1 \
-    PKG_CONFIG_PATH="/usr/lib/arm-linux-gnueabi/pkgconfig/:${PKG_CONFIG_PATH}"
+    PKG_CONFIG_PATH="/usr/lib/arm-linux-gnueabi/pkgconfig/:${PKG_CONFIG_PATH}" \
+    CROSS_CMAKE_SYSTEM_NAME=Linux \
+    CROSS_CMAKE_SYSTEM_PROCESSOR=arm \
+    CROSS_CMAKE_CRT=gnu \
+    CROSS_CMAKE_OBJECT_FLAGS="-ffunction-sections -fdata-sections -fPIC -march=armv6 -marm -mfloat-abi=soft"

docker/Dockerfile.arm-unknown-linux-gnueabihf

@@ -24,14 +24,21 @@ COPY qemu.sh /
 RUN /qemu.sh arm
 
 COPY qemu-runner base-runner.sh /
+COPY toolchain.cmake /opt/toolchain.cmake
 
 ENV CROSS_TOOLCHAIN_PREFIX=arm-unknown-linux-gnueabihf-
 ENV CROSS_SYSROOT=/x-tools/arm-unknown-linux-gnueabihf/arm-unknown-linux-gnueabihf/sysroot/
+ENV CROSS_TARGET_RUNNER="/qemu-runner armhf"
 ENV CARGO_TARGET_ARM_UNKNOWN_LINUX_GNUEABIHF_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc \
-    CARGO_TARGET_ARM_UNKNOWN_LINUX_GNUEABIHF_RUNNER="/qemu-runner armhf" \
+    CARGO_TARGET_ARM_UNKNOWN_LINUX_GNUEABIHF_RUNNER="$CROSS_TARGET_RUNNER" \
     AR_arm_unknown_linux_gnueabihf="$CROSS_TOOLCHAIN_PREFIX"ar \
     CC_arm_unknown_linux_gnueabihf="$CROSS_TOOLCHAIN_PREFIX"gcc \
     CXX_arm_unknown_linux_gnueabihf="$CROSS_TOOLCHAIN_PREFIX"g++ \
+    CMAKE_TOOLCHAIN_FILE_arm_unknown_linux_gnueabihf=/opt/toolchain.cmake \
     BINDGEN_EXTRA_CLANG_ARGS_arm_unknown_linux_gnueabihf="--sysroot=$CROSS_SYSROOT" \
     QEMU_LD_PREFIX="$CROSS_SYSROOT" \
-    RUST_TEST_THREADS=1
+    RUST_TEST_THREADS=1 \
+    CROSS_CMAKE_SYSTEM_NAME=Linux \
+    CROSS_CMAKE_SYSTEM_PROCESSOR=arm \
+    CROSS_CMAKE_CRT=gnu \
+    CROSS_CMAKE_OBJECT_FLAGS="-ffunction-sections -fdata-sections -fPIC -march=armv6 -marm -mfpu=vfp"

docker/Dockerfile.arm-unknown-linux-musleabi

@@ -26,12 +26,19 @@ COPY musl-symlink.sh /
 RUN /musl-symlink.sh $CROSS_SYSROOT arm
 
 COPY qemu-runner base-runner.sh /
+COPY toolchain.cmake /opt/toolchain.cmake
 
+ENV CROSS_TARGET_RUNNER="/qemu-runner arm"
 ENV CARGO_TARGET_ARM_UNKNOWN_LINUX_MUSLEABI_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc \
-    CARGO_TARGET_ARM_UNKNOWN_LINUX_MUSLEABI_RUNNER="/qemu-runner arm" \
+    CARGO_TARGET_ARM_UNKNOWN_LINUX_MUSLEABI_RUNNER="$CROSS_TARGET_RUNNER" \
     AR_arm_unknown_linux_musleabi="$CROSS_TOOLCHAIN_PREFIX"ar \
     CC_arm_unknown_linux_musleabi="$CROSS_TOOLCHAIN_PREFIX"gcc \
     CXX_arm_unknown_linux_musleabi="$CROSS_TOOLCHAIN_PREFIX"g++ \
+    CMAKE_TOOLCHAIN_FILE_arm_unknown_linux_musleabi=/opt/toolchain.cmake \
     BINDGEN_EXTRA_CLANG_ARGS_arm_unknown_linux_musleabi="--sysroot=$CROSS_SYSROOT" \
     QEMU_LD_PREFIX="$CROSS_SYSROOT" \
-    RUST_TEST_THREADS=1
+    RUST_TEST_THREADS=1 \
+    CROSS_CMAKE_SYSTEM_NAME=Linux \
+    CROSS_CMAKE_SYSTEM_PROCESSOR=arm \
+    CROSS_CMAKE_CRT=musl \
+    CROSS_CMAKE_OBJECT_FLAGS="-ffunction-sections -fdata-sections -fPIC -march=armv6 -marm -mfloat-abi=soft"

docker/Dockerfile.arm-unknown-linux-musleabihf

@@ -27,12 +27,19 @@ COPY musl-symlink.sh /
 RUN /musl-symlink.sh $CROSS_SYSROOT armhf
 
 COPY qemu-runner base-runner.sh /
+COPY toolchain.cmake /opt/toolchain.cmake
 
+ENV CROSS_TARGET_RUNNER="/qemu-runner armhf"
 ENV CARGO_TARGET_ARM_UNKNOWN_LINUX_MUSLEABIHF_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc \
-    CARGO_TARGET_ARM_UNKNOWN_LINUX_MUSLEABIHF_RUNNER="/qemu-runner armhf" \
+    CARGO_TARGET_ARM_UNKNOWN_LINUX_MUSLEABIHF_RUNNER="$CROSS_TARGET_RUNNER" \
     AR_arm_unknown_linux_musleabihf="$CROSS_TOOLCHAIN_PREFIX"ar \
     CC_arm_unknown_linux_musleabihf="$CROSS_TOOLCHAIN_PREFIX"gcc \
     CXX_arm_unknown_linux_musleabihf="$CROSS_TOOLCHAIN_PREFIX"g++ \
+    CMAKE_TOOLCHAIN_FILE_arm_unknown_linux_musleabihf=/opt/toolchain.cmake \
     BINDGEN_EXTRA_CLANG_ARGS_arm_unknown_linux_musleabihf="--sysroot=$CROSS_SYSROOT" \
     QEMU_LD_PREFIX="$CROSS_SYSROOT" \
-    RUST_TEST_THREADS=1
+    RUST_TEST_THREADS=1 \
+    CROSS_CMAKE_SYSTEM_NAME=Linux \
+    CROSS_CMAKE_SYSTEM_PROCESSOR=arm \
+    CROSS_CMAKE_CRT=musl \
+    CROSS_CMAKE_OBJECT_FLAGS="-ffunction-sections -fdata-sections -fPIC -march=armv6 -marm -mfpu=vfp"

docker/Dockerfile.armv5te-unknown-linux-gnueabi

@@ -24,15 +24,22 @@ COPY qemu.sh /
 RUN /qemu.sh arm
 
 COPY qemu-runner base-runner.sh /
+COPY toolchain.cmake /opt/toolchain.cmake
 
 ENV CROSS_TOOLCHAIN_PREFIX=arm-linux-gnueabi-
 ENV CROSS_SYSROOT=/usr/arm-linux-gnueabi
+ENV CROSS_TARGET_RUNNER="/qemu-runner arm"
 ENV CARGO_TARGET_ARMV5TE_UNKNOWN_LINUX_GNUEABI_LINKER="$CROSS_TOOLCHAIN_PREFIX"gcc \
-    CARGO_TARGET_ARMV5TE_UNKNOWN_LINUX_GNUEABI_RUNNER="/qemu-runner arm" \
+    CARGO_TARGET_ARMV5TE_UNKNOWN_LINUX_GNUEABI_RUNNER="$CROSS_TARGET_RUNNER" \
     AR_armv5te_unknown_linux_gnueabi="$CROSS_TOOLCHAIN_PREFIX"ar \
     CC_armv5te_unknown_linux_gnueabi="$CROSS_TOOLCHAIN_PREFIX"gcc \
     CXX_armv5te_unknown_linux_gnueabi="$CROSS_TOOLCHAIN_PREFIX"g++ \
+    CMAKE_TOOLCHAIN_FILE_armv5te_unknown_linux_gnueabi=/opt/toolchain.cmake \
     BINDGEN_EXTRA_CLANG_ARGS_armv5te_unknown_linux_gnueabi="--sysroot=$CROSS_SYSROOT" \
     QEMU_LD_PREFIX="$CROSS_SYSROOT" \
     RUST_TEST_THREADS=1 \
-    PKG_CONFIG_PATH="/usr/lib/arm-linux-gnueabi/pkgconfig/:${PKG_CONFIG_PATH}"
+    PKG_CONFIG_PATH="/usr/lib/arm-linux-gnueabi/pkgconfig/:${PKG_CONFIG_PATH}" \
+    CROSS_CMAKE_SYSTEM_NAME=Linux \
+    CROSS_CMAKE_SYSTEM_PROCESSOR=arm \
+    CROSS_CMAKE_CRT=gnu \
+    CROSS_CMAKE_OBJECT_FLAGS="-ffunction-sections -fdata-sections -fPIC -march=armv5te -marm -mfloat-abi=soft"