new: debian docker targets for cross-compiling

This provides a basic Debian install with access to the emdebian cross
compilers. The debian-armhf-cross and debian-arm64-cross targets build
on the basic Debian image to allow cross compiling to those targets.

A new environment variable (QEMU_CONFIGURE_OPTS) is set as part of the
docker container and passed to the build to specify the
--cross-prefix. The user still calls the build in the usual way, for
example:

  make docker-test-build@debian-arm64-cross \
    TARGET_LIST="aarch64-softmmu,aarch64-linux-user"

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20170220105139.21581-3-alex.bennee@linaro.org>
Signed-off-by: Fam Zheng <famz@redhat.com>

tests/docker/Makefile.include

@@ -54,6 +54,10 @@ docker-image-%: $(DOCKER_FILES_DIR)/%.docker
 		$(if $(EXECUTABLE),--include-executable=$(EXECUTABLE)),\
 		"BUILD","$*")
 
+# Enforce dependancies for composite images
+docker-image-debian-armhf-cross: docker-image-debian
+docker-image-debian-arm64-cross: docker-image-debian
+
 # Expand all the pre-requistes for each docker image and test combination
 $(foreach i,$(DOCKER_IMAGES), \
 	$(foreach t,$(DOCKER_TESTS) $(DOCKER_TOOLS), \

tests/docker/common.rc

@@ -29,7 +29,7 @@ build_qemu()
     config_opts="--enable-werror \
                  ${TARGET_LIST:+--target-list=${TARGET_LIST}} \
                  --prefix=$PWD/install \
-                 $EXTRA_CONFIGURE_OPTS \
+                 $QEMU_CONFIGURE_OPTS $EXTRA_CONFIGURE_OPTS \
                  $@"
     echo "Configure options:"
     echo $config_opts

tests/docker/dockerfiles/debian-arm64-cross.docker

@@ -0,0 +1,15 @@
+#
+# Docker arm64 cross-compiler target
+#
+# This docker target builds on the base debian image.
+#
+FROM qemu:debian
+
+# Add the foreign architecture we want and install dependencies
+RUN dpkg --add-architecture arm64
+RUN apt update
+RUN apt install -yy crossbuild-essential-arm64
+RUN apt-get build-dep -yy -a arm64 qemu
+
+# Specify the cross prefix for this image (see tests/docker/common.rc)
+ENV QEMU_CONFIGURE_OPTS --cross-prefix=aarch64-linux-gnu-

tests/docker/dockerfiles/debian-armhf-cross.docker

@@ -0,0 +1,15 @@
+#
+# Docker armhf cross-compiler target
+#
+# This docker target builds on the base debian image.
+#
+FROM qemu:debian
+
+# Add the foreign architecture we want and install dependencies
+RUN dpkg --add-architecture armhf
+RUN apt update
+RUN apt install -yy crossbuild-essential-armhf
+RUN apt-get build-dep -yy -a armhf qemu
+
+# Specify the cross prefix for this image (see tests/docker/common.rc)
+ENV QEMU_CONFIGURE_OPTS --cross-prefix=arm-linux-gnueabihf-

tests/docker/dockerfiles/debian.docker

@@ -0,0 +1,25 @@
+#
+# Docker multiarch cross-compiler target
+#
+# This docker target is builds on Debian and Emdebian's cross compiler targets
+# to build distro with a selection of cross compilers for building test binaries.
+#
+# On its own you can't build much but the docker-foo-cross targets
+# build on top of the base debian image.
+#
+FROM debian:stable-slim
+
+# Setup some basic tools we need
+RUN apt update
+RUN apt install -yy curl aptitude
+
+# Setup Emdebian
+RUN echo "deb http://emdebian.org/tools/debian/ jessie main" >> /etc/apt/sources.list
+RUN curl http://emdebian.org/tools/debian/emdebian-toolchain-archive.key | apt-key add -
+
+# Duplicate deb line as deb-src
+RUN cat /etc/apt/sources.list | sed "s/deb/deb-src/" >> /etc/apt/sources.list
+
+# Install common build utilities
+RUN apt update
+RUN apt install -yy build-essential clang