В Wed, 8 Oct 2014 20:38:29 -0300 Paulo Flabiano Smorigo <pfsmor...@linux.vnet.ibm.com> пишет:
> Mon, Sep 29, 2014 at 10:30:16PM +0400, Andrei Borzenkov wrote: > > В Sat, 27 Sep 2014 09:06:53 +0400 > > Andrei Borzenkov <arvidj...@gmail.com> пишет: > > > > > В Fri, 26 Sep 2014 16:29:40 -0300 > > > Paulo Flabiano Smorigo <pfsmor...@linux.vnet.ibm.com> пишет: > > > > > > > * conf/Makefile.common [COND_powerpc_ieee1275] (CFLAGS_PLATFORM): Add > > > > -msoft-float -mno-vsx -mno-altivec. > > > > > > > > Also-By: Adhemerval Zanella <azane...@linux.vnet.ibm.com> > > > > --- > > > > ChangeLog | 7 +++++++ > > > > conf/Makefile.common | 3 +++ > > > > 2 files changed, 10 insertions(+) > > > > > > > > diff --git a/ChangeLog b/ChangeLog > > > > index 192e8bc..40eb90c 100644 > > > > --- a/ChangeLog > > > > +++ b/ChangeLog > > > > @@ -1,3 +1,10 @@ > > > > +2014-09-26 Paulo Flabiano Smorigo <pfsmor...@linux.vnet.ibm.com> > > > > + > > > > + Add flags for powerpc in order to avoid exceptions > > > > + > > > > + * conf/Makefile.common [COND_powerpc_ieee1275] > > > > (CFLAGS_PLATFORM): Add > > > > + -msoft-float -mno-vsx -mno-altivec. > > > > + > > > > 2014-09-25 Colin Watson <cjwat...@ubuntu.com> > > > > > > > > Fix in-tree --platform=none > > > > diff --git a/conf/Makefile.common b/conf/Makefile.common > > > > index 51fbaf9..57c491a 100644 > > > > --- a/conf/Makefile.common > > > > +++ b/conf/Makefile.common > > > > @@ -22,6 +22,9 @@ endif > > > > if COND_arm64 > > > > CFLAGS_PLATFORM += -mcmodel=large > > > > endif > > > > +if COND_powerpc_ieee1275 > > > > + CFLAGS_PLATFORM += -msoft-float -mno-vsx -mno-altivec > > > > +endif > > > > > > > > #FIXME: discover and check XEN headers > > > > CPPFLAGS_XEN = -I/usr/include > > > > > > Thank you! I confirm that this patch works and does not break grub on > > > earlier CPU :) > > > > > > There are still differences in generated code, so we probably need to > > > tune some more flags. > > > > I looked at compiler options for PowerPC and I think instead of trying > > to catch individual flags which may change with every release we should > > simply force the most common platform by > > > > +if COND_powerpc_ieee1275 > > + CFLAGS_PLATFORM += -mcpu=powerpc -mtune=powerpc > > +endif > > > > > > This makes sure result is identical on every platform and provides most > > generic code that is expected to run on every(?) system. > > > > WDYT? > > Hi Andrei, > > Sorry to take so long to answer your question. > > After an internal discussion with some toolchain experts we found out > that your approach is good. It works and it's more generic but we think > that we should change it a little bit: > > * skip -mtune, not really necessary Fine if you say so. > * add "-msoft-float" to be completly safe. > Is it really necessary? I do not think grub is using floating point anywhere. > Something like: > > +if COND_powerpc_ieee1275 > + CFLAGS_PLATFORM += -mcpu=powerpc -msoft-float > +endif > Should not we also add -mbig-endian here, and not in configure? This is really something we always use, not something we need to detect dynamically. > This approach is similar to what the linux kernel do. > > In addition, they recomend to set FP MSR value to zero as well. > > Andrei, Vladimir, agree? > Could you resend your patches as discussed and rebased to git master, so they are easier to review and comment? _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
