Re: [Qemu-devel] [PATCH v2 31/43] tests/tcg: enable building for MIPS

[Fam Zheng]

On Thu, 04/19 23:57, Philippe Mathieu-Daudé wrote:
> On 04/19/2018 02:58 PM, Peter Maydell wrote:
> > On 19 April 2018 at 18:49, Alex Bennée <address@hidden> wrote:
> >> Philippe Mathieu-Daudé <address@hidden> writes:
> >>> On 04/19/2018 10:58 AM, Alex Bennée wrote:
> >>>> This doesn't add any additional tests but enables building the
> >>>> multiarch tests for MIPS using docker cross compilers. We don't have a
> >>>> cross compiler for mips64 big endian though.
> >>>
> >>> Oh we have one, using CFLAGS+=-EB
> >>>
> >>> we don't have cross libraries although.
> >>
> >> Yeah I thought the same with the ARM compilers (-mbig-endian) but it's
> >> the libraries that let us down. If, as you say, newlib gets this right I
> >> suspect we should use that to build the compilers not supported out of
> >> the box by Debian.
> > 
> > I don't think we really want to get into the business of
> > building our own cross compilers if we can avoid it...it's harder
> > than it looks and we would be essentially reinventing the wheel.
> 
> I totally agree.
> 
> I'v been looking at existing maintained images we can use to
> cross-build, so we only have to pull (download) and image and use it,
> not wasting cpu time building it.
> 
> However some images might be huge, full of things we don't need. But I
> prefer that rather than having to maintain cross toolchains.
> 
> An example I like to use is the coreboot-sdk, designed to build
> i386/amd64 binaries, it fulfills our needs. But takes 2GB...
> 
> $ docker pull coreboot/coreboot-sdk:1.47
> 1.47: Pulling from coreboot/coreboot-sdk
> 3d6aedfc3e47: Downloading [>              ]  538.2kB/1.201GB
> d23c9a72f1e5: Waiting
> 
> Another candidate is crossbuild, ~1GB
> $ docker pull multiarch/crossbuild

Makes sense to me. It is not insanely big. It might take some time to download
depending on the network but it's more likely a one-off thing compared to
building one from a handcraft dockerfile we make, which probably will involve
even more downloading time and disk usage.

Fam