chromebook_coral: build failure

[Simon Glass]

Hi Wolfgang,

On Tue, 4 Aug 2020 at 01:59, Wolfgang Wallner
<wolfgang.wallner at br-automation.com> wrote:
>
> Hi Simon,
>
> -----"Simon Glass" <sjg at chromium.org> schrieb: -----
> > Betreff: Re: chromebook_coral: build failure
> >
> > Hi Wolfgang,
> >
> > On Fri, 31 Jul 2020 at 05:44, Wolfgang Wallner
> > <wolfgang.wallner at br-automation.com> wrote:
> > >
> > > Hi Simon,
> > >
> > > while trying out your ACPI patches I tried to compile
> > chromebook_coral_defconfig
> > > as a reference. Building this defconfig fails for multiple
> > definitions
> > > of "_X86EMU_env":
> > >
> > > $ git checkout v2020.07
> > > $ make distclean
> > > $ make chromebook_coral_defconfig
> > > $ make
> > >
> > > [...]
> > >   LDS     u-boot.lds
> > >   LD      u-boot
> > > ld.bfd: drivers/built-in.o:(.bss._X86EMU_env+0x0): multiple
> > definition of `_X86EMU_env';
> > arch/x86/lib/built-in.o:(.bss._X86EMU_env+0x0): first defined here
> > > make: *** [Makefile:1755: u-boot] Error 1
> > >
> > > A quick and dirty workaround was to drop "#define CONFIG_BIOSEMU"
> > from
> > > include/configs/x86-chromebook.h. With this change
> > chromebook_coral_defconfig
> > > compiles fine.
> > >
> > > Do you know what is going on here, and what might be a proper fix?
> >
> > I don't see that problem myself, [...]
>
> It seems to be triggered by a change of default flags in GCC 10.
>
> I can reliably reproduce the build error on my main machine (Arch Linux with
> GCC 10), but it builds fine on a Debian 10 with GCC 8.
> A colleague told me about "-fno-common", which was changed to be on by default
> in GCC 10:
>
> https://gcc.gnu.org/gcc-10/porting_to.html
>
> I can build chromebook_coral_defconfig on my Arch with GCC 10 with:
>
>    make KCFLAGS="-fcommon"
>
> However, I'm not sure what the initial problem is, as I don't know the relevant
> code parts. Both of the following files declare a global variable
> "_X86EMU_env":
>
>   drivers/bios_emulator/x86emu/sys.c
>   arch/x86/lib/bios.c
>
> Should they both be part of the build for Chromebook Coral?

I think I figured this out and sent a patch. Thanks for explanation.

>
> > [...] but I do see an ACPI compile problem
> > now. that I rebase. I have added a patch for that and pushed the tree
> > to u-boot-dm/coral-working
>
> Yes, this is the reason why I wanted to compile chromebook_coral_defconfig
> as a reference :) I saw the ACPI compile problem when I tried your ACPI
> patches on my APL board and wanted to see whether I had broken something.
>
> Could you please move the fix to the beginning of the part D series when you
> send V2? It might make testing individual patches of that series easier if
> the fix is at the beginning.
>

I can't remember what the ACPI compile problem is, sorry.

Regards,
Simon