tests/docker: use prebuilt toolchain for debian-hexagon-cross

The current docker image for cross compiling hexagon guests
is manually built since it takes >2 hours to build from source.

This patch:
 1. Solves the above issue by using the prebuilt clang
    toolchain hosted on CodeLinaro [1] and maintained by QUIC [2].
 2. The dockerfile is also switched from multi-stage to single stage
    build to allow the CI docker engine to reuse the layer cache.
 3. Re-enables the hexagon-cross-container job to be always run in
    CI and makes it a non-optional dependency for the
    build-user-hexagon job.

The changes for 1 & 2 together bring down the build time to
~3 minutes in GitLab CI when cache is reused and ~9 minutes
when cache cannot be reused.

[1]: https://github.com/CodeLinaro/hexagon-builder
[2]: https://github.com/quic/toolchain_for_hexagon/releases/

Signed-off-by: Mukilan Thiyagarajan <quic_mthiyaga@quicinc.com>
[AJB: also tweak MAINTAINERS, remove QEMU_JOB_ONLY_FORKS and comment]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20221219144354.11659-1-quic_mthiyaga@quicinc.com>
Message-Id: <20221221090411.1995037-6-alex.bennee@linaro.org>

3 files changed, 19 insertions, 179 deletions

diff --git a/tests/docker/Makefile.include b/tests/docker/Makefile.include
index fc7a3b7e71..665ddde518 100644
--- a/tests/docker/Makefile.include
+++ b/tests/docker/Makefile.include
@@ -109,10 +109,6 @@ debian-toolchain-run = \
 			"PREPARE", $1))
 debian-toolchain = $(call debian-toolchain-run,$(patsubst docker-image-%,%,$1))
 
-docker-image-debian-hexagon-cross: $(DOCKER_FILES_DIR)/debian-hexagon-cross.docker \
-	$(DOCKER_FILES_DIR)/debian-hexagon-cross.d/build-toolchain.sh
-	$(call debian-toolchain, $@)
-
 docker-image-debian-microblaze-cross: $(DOCKER_FILES_DIR)/debian-toolchain.docker \
     $(DOCKER_FILES_DIR)/debian-microblaze-cross.d/build-toolchain.sh
 	$(call debian-toolchain, $@)
diff --git a/tests/docker/dockerfiles/debian-hexagon-cross.d/build-toolchain.sh b/tests/docker/dockerfiles/debian-hexagon-cross.d/build-toolchain.sh
deleted file mode 100755
index 19b1c9f83e..0000000000
--- a/tests/docker/dockerfiles/debian-hexagon-cross.d/build-toolchain.sh
+++ /dev/null
@@ -1,141 +0,0 @@
-#!/bin/bash
-
-set -e
-
-BASE=$(readlink -f ${PWD})
-
-TOOLCHAIN_INSTALL=$(readlink -f "$TOOLCHAIN_INSTALL")
-ROOTFS=$(readlink -f "$ROOTFS")
-
-TOOLCHAIN_BIN=${TOOLCHAIN_INSTALL}/bin
-HEX_SYSROOT=${TOOLCHAIN_INSTALL}/hexagon-unknown-linux-musl
-HEX_TOOLS_TARGET_BASE=${HEX_SYSROOT}/usr
-
-function cdp() {
-  DIR="$1"
-  mkdir -p "$DIR"
-  cd "$DIR"
-}
-
-function fetch() {
-  DIR="$1"
-  URL="$2"
-  TEMP="$(readlink -f "$PWD/tmp.tar.gz")"
-  wget --quiet "$URL" -O "$TEMP"
-  cdp "$DIR"
-  tar xaf "$TEMP" --strip-components=1
-  rm "$TEMP"
-  cd -
-}
-
-build_llvm_clang() {
-  fetch "$BASE/llvm-project" "$LLVM_URL"
-  cdp "$BASE/build-llvm"
-
-  cmake -G Ninja \
-    -DCMAKE_BUILD_TYPE=Release \
-    -DCMAKE_INSTALL_PREFIX=${TOOLCHAIN_INSTALL} \
-    -DLLVM_ENABLE_LLD=ON \
-    -DLLVM_TARGETS_TO_BUILD="Hexagon" \
-    -DLLVM_ENABLE_PROJECTS="clang;lld" \
-    "$BASE/llvm-project/llvm"
-  ninja all install
-  cd ${TOOLCHAIN_BIN}
-  ln -sf clang hexagon-unknown-linux-musl-clang
-  ln -sf clang++ hexagon-unknown-linux-musl-clang++
-  ln -sf llvm-ar hexagon-unknown-linux-musl-ar
-  ln -sf llvm-objdump hexagon-unknown-linux-musl-objdump
-  ln -sf llvm-objcopy hexagon-unknown-linux-musl-objcopy
-  ln -sf llvm-readelf hexagon-unknown-linux-musl-readelf
-  ln -sf llvm-ranlib hexagon-unknown-linux-musl-ranlib
-
-  # workaround for now:
-  cat <<EOF > hexagon-unknown-linux-musl.cfg
--G0 --sysroot=${HEX_SYSROOT}
-EOF
-}
-
-build_clang_rt() {
-  cdp "$BASE/build-clang_rt"
-  cmake -G Ninja \
-    -DCMAKE_BUILD_TYPE=Release \
-    -DLLVM_CONFIG_PATH="$BASE/build-llvm/bin/llvm-config" \
-    -DCMAKE_ASM_FLAGS="-G0 -mlong-calls -fno-pic --target=hexagon-unknown-linux-musl " \
-    -DCMAKE_SYSTEM_NAME=Linux \
-    -DCMAKE_C_COMPILER="${TOOLCHAIN_BIN}/hexagon-unknown-linux-musl-clang" \
-    -DCMAKE_ASM_COMPILER="${TOOLCHAIN_BIN}/hexagon-unknown-linux-musl-clang" \
-    -DCMAKE_INSTALL_PREFIX=${HEX_TOOLS_TARGET_BASE} \
-    -DCMAKE_CROSSCOMPILING=ON \
-    -DCMAKE_C_COMPILER_FORCED=ON \
-    -DCMAKE_CXX_COMPILER_FORCED=ON \
-    -DCOMPILER_RT_BUILD_BUILTINS=ON \
-    -DCOMPILER_RT_BUILTINS_ENABLE_PIC=OFF \
-    -DCMAKE_SIZEOF_VOID_P=4 \
-    -DCOMPILER_RT_OS_DIR= \
-    -DCAN_TARGET_hexagon=1 \
-    -DCAN_TARGET_x86_64=0 \
-    -DCOMPILER_RT_SUPPORTED_ARCH=hexagon \
-    -DLLVM_ENABLE_PROJECTS="compiler-rt" \
-    "$BASE/llvm-project/compiler-rt"
-  ninja install-compiler-rt
-}
-
-build_musl_headers() {
-  fetch "$BASE/musl" "$MUSL_URL"
-  cd "$BASE/musl"
-  make clean
-  CC=${TOOLCHAIN_BIN}/hexagon-unknown-linux-musl-clang \
-    CROSS_COMPILE=hexagon-unknown-linux-musl \
-    LIBCC=${HEX_TOOLS_TARGET_BASE}/lib/libclang_rt.builtins-hexagon.a \
-    CROSS_CFLAGS="-G0 -O0 -mv65 -fno-builtin -fno-rounding-math --target=hexagon-unknown-linux-musl" \
-    ./configure --target=hexagon --prefix=${HEX_TOOLS_TARGET_BASE}
-  PATH=${TOOLCHAIN_BIN}:$PATH make CROSS_COMPILE= install-headers
-
-  cd ${HEX_SYSROOT}/..
-  ln -sf hexagon-unknown-linux-musl hexagon
-}
-
-build_kernel_headers() {
-  fetch "$BASE/linux" "$LINUX_URL"
-  mkdir -p "$BASE/build-linux"
-  cd "$BASE/linux"
-  make O=../build-linux ARCH=hexagon \
-   KBUILD_CFLAGS_KERNEL="-mlong-calls" \
-   CC=${TOOLCHAIN_BIN}/hexagon-unknown-linux-musl-clang \
-   LD=${TOOLCHAIN_BIN}/ld.lld \
-   KBUILD_VERBOSE=1 comet_defconfig
-  make mrproper
-
-  cd "$BASE/build-linux"
-  make \
-    ARCH=hexagon \
-    CC=${TOOLCHAIN_BIN}/clang \
-    INSTALL_HDR_PATH=${HEX_TOOLS_TARGET_BASE} \
-    V=1 \
-    headers_install
-}
-
-build_musl() {
-  cd "$BASE/musl"
-  make clean
-  CROSS_COMPILE=hexagon-unknown-linux-musl- \
-    AR=llvm-ar \
-    RANLIB=llvm-ranlib \
-    STRIP=llvm-strip \
-    CC=clang \
-    LIBCC=${HEX_TOOLS_TARGET_BASE}/lib/libclang_rt.builtins-hexagon.a \
-    CFLAGS="-G0 -O0 -mv65 -fno-builtin -fno-rounding-math --target=hexagon-unknown-linux-musl" \
-    ./configure --target=hexagon --prefix=${HEX_TOOLS_TARGET_BASE}
-  PATH=${TOOLCHAIN_BIN}/:$PATH make CROSS_COMPILE= install
-  cd ${HEX_TOOLS_TARGET_BASE}/lib
-  ln -sf libc.so ld-musl-hexagon.so
-  ln -sf ld-musl-hexagon.so ld-musl-hexagon.so.1
-  cdp ${HEX_TOOLS_TARGET_BASE}/../lib
-  ln -sf ../usr/lib/ld-musl-hexagon.so.1
-}
-
-build_llvm_clang
-build_kernel_headers
-build_musl_headers
-build_clang_rt
-build_musl
diff --git a/tests/docker/dockerfiles/debian-hexagon-cross.docker b/tests/docker/dockerfiles/debian-hexagon-cross.docker
index c4238e893f..8a0d748343 100644
--- a/tests/docker/dockerfiles/debian-hexagon-cross.docker
+++ b/tests/docker/dockerfiles/debian-hexagon-cross.docker
@@ -7,44 +7,29 @@
 #
 FROM docker.io/library/debian:11-slim
 
-# Install common build utilities
-RUN apt update && \
+# Duplicate deb line as deb-src
+RUN cat /etc/apt/sources.list | sed "s/^deb\ /deb-src /" >> /etc/apt/sources.list
+RUN apt-get update && \
     DEBIAN_FRONTEND=noninteractive apt install -yy eatmydata && \
     DEBIAN_FRONTEND=noninteractive eatmydata \
-    apt install -y --no-install-recommends \
-        bison \
+# Install common build utilities
+    apt-get install -y --no-install-recommends \
+        curl \
+        xz-utils \
         ca-certificates \
-        clang \
-        cmake \
+        bison \
         flex \
-        gcc \
-        lld \
-        make \
-        ninja-build \
-        python3 \
-        rsync \
-        wget \
-        xz-utils
-
-ENV TOOLCHAIN_INSTALL /usr/local
-ENV ROOTFS /usr/local
-
-ENV LLVM_URL https://github.com/llvm/llvm-project/archive/bfcd21876adc3498065e4da92799f613e730d475.tar.gz
-ENV MUSL_URL https://github.com/quic/musl/archive/aff74b395fbf59cd7e93b3691905aa1af6c0778c.tar.gz
-ENV LINUX_URL https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.6.18.tar.xz
-
-ADD build-toolchain.sh /root/hexagon-toolchain/build-toolchain.sh
-
-RUN cd /root/hexagon-toolchain && ./build-toolchain.sh
-
-FROM docker.io/library/debian:11-slim
-# Duplicate deb line as deb-src
-RUN cat /etc/apt/sources.list | sed "s/^deb\ /deb-src /" >> /etc/apt/sources.list
+        git \
+        ninja-build && \
 # Install QEMU build deps for use in CI
-RUN apt update && \
-    DEBIAN_FRONTEND=noninteractive apt install -yy eatmydata && \
-    DEBIAN_FRONTEND=noninteractive eatmydata apt install -yy bison flex git ninja-build && \
     DEBIAN_FRONTEND=noninteractive eatmydata \
     apt build-dep -yy --arch-only qemu
-COPY --from=0 /usr/local /usr/local
-ENV PATH $PATH:/usr/local/bin/
+
+
+ENV TOOLCHAIN_INSTALL /opt
+ENV TOOLCHAIN_RELEASE 15.0.3
+ENV TOOLCHAIN_BASENAME "clang+llvm-${TOOLCHAIN_RELEASE}-cross-hexagon-unknown-linux-musl"
+ENV TOOLCHAIN_URL https://codelinaro.jfrog.io/artifactory/codelinaro-toolchain-for-hexagon/v${TOOLCHAIN_RELEASE}/${TOOLCHAIN_BASENAME}.tar.xz
+
+RUN curl -#SL "$TOOLCHAIN_URL" | tar -xJC "$TOOLCHAIN_INSTALL"
+ENV PATH $PATH:${TOOLCHAIN_INSTALL}/${TOOLCHAIN_BASENAME}/x86_64-linux-gnu/bin