docker: add debian/mips64el image

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
diff --git a/tests/docker/Makefile.include b/tests/docker/Makefile.include
index e0807c0..5a82836 100644
--- a/tests/docker/Makefile.include
+++ b/tests/docker/Makefile.include
@@ -63,6 +63,7 @@
 docker-image-debian-armhf-cross: docker-image-debian9
 docker-image-debian-arm64-cross: docker-image-debian9
 docker-image-debian-mips-cross: docker-image-debian9
+docker-image-debian-mips64el-cross: docker-image-debian9
 docker-image-debian-powerpc-cross: docker-image-debian8
 docker-image-debian-ppc64el-cross: docker-image-debian9
 docker-image-debian-s390x-cross: docker-image-debian9
diff --git a/tests/docker/dockerfiles/debian-mips64el-cross.docker b/tests/docker/dockerfiles/debian-mips64el-cross.docker
new file mode 100644
index 0000000..fd2aafe
--- /dev/null
+++ b/tests/docker/dockerfiles/debian-mips64el-cross.docker
@@ -0,0 +1,30 @@
+#
+# Docker mips64el cross-compiler target
+#
+# This docker target builds on the debian Stretch base image.
+#
+
+FROM qemu:debian9
+
+MAINTAINER Philippe Mathieu-Daudé <f4bug@amsat.org>
+
+# Add the foreign architecture we want and install dependencies
+RUN dpkg --add-architecture mips64el && \
+    apt-get update
+RUN DEBIAN_FRONTEND=noninteractive eatmydata \
+    apt-get install -y --no-install-recommends \
+        gcc-mips64el-linux-gnuabi64
+
+RUN DEBIAN_FRONTEND=noninteractive eatmydata \
+    apt-get build-dep -yy -a mips64el qemu
+
+# Specify the cross prefix for this image (see tests/docker/common.rc)
+ENV QEMU_CONFIGURE_OPTS --cross-prefix=mips64el-linux-gnuabi64-
+
+# Install extra libraries to increase code coverage
+RUN DEBIAN_FRONTEND=noninteractive eatmydata \
+    apt-get install -y --no-install-recommends \
+        libbz2-dev:mips64el \
+        liblzo2-dev:mips64el \
+        librdmacm-dev:mips64el \
+        libsnappy-dev:mips64el