[Skiboot] [RFC PATCH 0/3] fixes for building BE target with LE toolchain

[Nicholas Piggin]

On Wed, 19 Jul 2017 15:19:11 +1000
Stewart Smith <stewart at linux.vnet.ibm.com> wrote:

> Nicholas Piggin <npiggin at gmail.com> writes:
> > These are a few patches I carry around in the interest of being
> > able to build BE firmware and LE kernel on my development machine
> > using only one toolchain. They tend to have the capability to generate
> > code for either endian, it's just defaults that don't always align.
> >
> > Nicholas Piggin (3):
> >   build: LDFLAGS pass -pie flag explicitly to ld
> >   build: CFLAGS compile with -fpie and -fno-pic
> >   build: CFLAGS compile with -mcpu=power7  
> 
> Without having built (or boot tested) with them, everything *looks* sane
> enough... I think the P7 target is good, certainly the reality of
> skiboot for the forseeable future :)

It's just a slight convenience for me, but I thought it would be a good
idea for upstream to make some of these options explicit, so it doesn't
come to bite us if the production toolchain is upgraded and something
changes. We really should be explicit about the -fpie options at least,
I think.

> Anything special about these toolchains? And should we add them to the
> Travis CI magic so that we don't regress?

Not that I know of, they are just the standard debian cross compilers.
They do look to be ./configure--ed with slightly different options which
is where some of the differences come from.

This series could result in some code generation difference even with the
BE compiler because that would target some generic powerpc64 ISA by
default, so just be aware it's not a noop.

Thanks,
Nick