Re: [OpenBIOS] openbios cross compile fails with gcc 5.2

[Laurent Vivier]

Le 21/11/2015 13:46, Mark Cave-Ayland a écrit :
> On 21/11/15 02:03, Cole Robinson wrote:
> > Hi all,
> >
> > openbios fails to build with gcc 5.2 cross compilers. This is using fedora 23
> > packages. There's a bug here with complete info:
> >
> > https://bugzilla.redhat.com/show_bug.cgi?id=1282890
> >
> > The error is:
> >
> > powerpc64-linux-gnu-gcc $EXTRACFLAGS -m32 -msoft-float -fno-builtin-bcopy
> > -fno-builtin-log2 -Os -g -DNATIVE_BITWIDTH_EQUALS_HOST_BITWIDTH
> > -USWAP_ENDIANNESS -Wall -Wredundant-decls -Wshadow -Wpointer-arith
> > -Wstrict-prototypes -Wmissing-declarations -Wundef -Wendif-labels
> > -Wstrict-aliasing -Wwrite-strings -Wmissing-prototypes -Wnested-externs
> > -Werror -MMD -MP -MT target/arch/ppc/qemu/ofmem.o -MF
> > 'target/arch/ppc/qemu/ofmem.d' -I/root/openbios/openbios-1.1/include
> > -I/root/openbios/openbios-1.1/kernel/include -I./target/include -c -o
> > target/arch/ppc/qemu/ofmem.o /root/openbios/openbios-1.1/arch/ppc/qemu/ofmem.c
> > /tmp/ccznzzOd.s: Assembler messages:
> > /tmp/ccznzzOd.s:551: Error: missing operand
> > rules.mak:309: recipe for target 'target/arch/ppc/qemu/ofmem.o' failed
> > make[1]: *** [target/arch/ppc/qemu/ofmem.o] Error 1
> > make[1]: *** Waiting for unfinished jobs....
> > make[1]: Leaving directory '/root/openbios/openbios-1.1/obj-ppc'
> > Makefile:32: recipe for target 'subdir-ppc' failed
> > make: *** [subdir-ppc] Error 2
> > error: Bad exit status from /var/tmp/rpm-tmp.DSB86j (%build)
> >
> > David Howells' commented in the bug with a suggested fix... but I don't even
> > have a setup to test openbios so I'd prefer if someone else cooks up the patch :)
>
> My understanding is that the earliest CPU we need to be supporting for
> PPC is the 750 (which should be POWER7 series) although there was

I think 750 (G3) is POWER2, 970 (G5) is POWER4
> interest in using OpenBIOS for PReP which I believe is a 604?
>
> Hervé/Laurent in particular - any further thoughts on this?

by default gcc-5.1 produces POWER4 assembler (".machine power4").

If we target 750, we should use "-mcpu=G3". it generates a ".machine
ppc", whereas "-mcpu=G5" generates ".machine power4".

I'm going to reproduce the problem and propose a fix.

Laurent