Re: [Qemu-devel] [PATCH v3 20/20] docker: add linux-user powered cross builder for QEMU

[Philippe Mathieu-Daudé]

On 07/02/2018 11:30 AM, Alex Bennée wrote:
> We can't use cross compilers in the current Debian stable and Debian
> sid is sketchy as hell. So for powerpc fall back to dog-fooding our
> own linux-user to do the build.
> 
> As we can only build the base image with a suitably configured
> source tree we fall back to checking for it's existence when we can't
> build it from scratch. However this does mean you don't have to keep
> a static powerpc-linux-user in your active configuration just to
> update the cross build image.
> 
> Signed-off-by: Alex Bennée <address@hidden>
> 
> ---
> v3
>   - fix for rename of docker-binfmt-image-debian-powerpc-user
> ---
>  tests/docker/Makefile.include                 | 29 +++++++++++++++++++
>  .../debian-powerpc-user-cross.docker          | 13 +++++++++
>  2 files changed, 42 insertions(+)
>  create mode 100644 tests/docker/dockerfiles/debian-powerpc-user-cross.docker
> 
> diff --git a/tests/docker/Makefile.include b/tests/docker/Makefile.include
> index fdc87b8a57..85801702dd 100644
> --- a/tests/docker/Makefile.include
> +++ b/tests/docker/Makefile.include
> @@ -119,6 +119,31 @@ docker-image-travis: NOUSER=1
>  # Specialist build images, sometimes very limited tools
>  docker-image-tricore-cross: docker-image-debian9
>  
> +# Rules for building linux-user powered images
> +#
> +# These are slower than using native cross compiler setups but can
> +# work around issues with poorly working multi-arch systems and broken
> +# packages.
> +
> +ifeq ($(filter 
> ppc-linux-user,$(TARGET_LIST))$(CONFIG_STATIC),ppc-linux-usery)
> +# Jessie is the last supported release for powerpc, but multi-arch is
> +# broken so we need a qemu-linux-user for this target
> +docker-binfmt-image-debian-powerpc-user: DEB_ARCH = powerpc
> +docker-binfmt-image-debian-powerpc-user: DEB_TYPE = jessie
> +docker-binfmt-image-debian-powerpc-user: EXECUTABLE = 
> ${BUILD_DIR}/ppc-linux-user/qemu-ppc
> +DOCKER_USER_IMAGES += debian-powerpc-user
> +else
> +docker-binfmt-image-debian-powerpc-user:
> +     $(call quiet-command, \
> +             $(DOCKER_SCRIPT) check --quiet qemu:debian-powerpc-user \
> +                     $(DOCKER_FILES_DIR)/debian-bootstrap.docker, \
> +             "CHECK", "debian-powerpc-user exists")
> +endif
> +
> +# We build the QEMU compiler environment on top of the base image
> +docker-image-debian-powerpc-user-cross: 
> docker-binfmt-image-debian-powerpc-user
> +
> +
>  # Expand all the pre-requistes for each docker image and test combination
>  $(foreach i,$(filter-out $(DOCKER_INTERMEDIATE_IMAGES),$(DOCKER_IMAGES) 
> $(DOCKER_DEPRECATED_IMAGES)), \
>       $(foreach t,$(DOCKER_TESTS) $(DOCKER_TOOLS), \
> @@ -154,6 +179,10 @@ docker:
>       @echo
>       @echo 'Available container images:'
>       @echo '    $(DOCKER_IMAGES)'
> +ifneq ($(DOCKER_USER_IMAGES),)
> +     @echo 'Available linux-user images:'
> +     @echo '    $(DOCKER_USER_IMAGES)'
> +endif
>       @echo
>       @echo 'Available tests:'
>       @echo '    $(DOCKER_TESTS)'
> diff --git a/tests/docker/dockerfiles/debian-powerpc-user-cross.docker 
> b/tests/docker/dockerfiles/debian-powerpc-user-cross.docker
> new file mode 100644
> index 0000000000..eadb142792
> --- /dev/null
> +++ b/tests/docker/dockerfiles/debian-powerpc-user-cross.docker
> @@ -0,0 +1,13 @@
> +#
> +# Docker powerpc cross-compiler target for QEMU
> +#
> +# We can't use current Debian stable cross-compilers to build powerpc
> +# as it has been dropped as a release architecture. Using Debian Sid
> +# is just far too sketchy a build environment. This leaves us the
> +# final option of using linux-user. This image is based of the
> +# debootstrapped qemu:debian-powerpc-user but doesn't need any extra
> +# magic once it is setup.
> +#
> +FROM qemu:debian-powerpc-user
> +
> +RUN apt-get update && apt-get build-dep -yy qemu

RUN apt-get update && \
    DEBIAN_FRONTEND=noninteractive apt-get build-dep -yy qemu

to avoid the various:

...
debconf: (TERM is not set, so the dialog frontend is not usable.)
...

Also I think we should use the "Don't rebuild man-db" trick:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=561539#15