Re: [Gnewsense-dev] binutils which works around loongson2f NOP bug by default

[Mark H Weaver]

On Thu, Apr 08, 2010 at 08:06:59PM +0930, Karl Goetz wrote:
> This issue has been discussed on debian-mips, and on this list
> previously. Are you aware of those discussions?

I've found some discussions about the loongson2f NOP and JUMP
workarounds, but I've been unable to find earlier suggestions that the
NOP workaround should be applied by default.  Pointers welcome.

> > * Added --enable-fix-loongson2f-nop option to gas/configure,
> >   which makes -mfix-loongson2f-nop the default for MIPS targets
> >   (unless overridden by -mnofix-loongson2f-nop).
> > 
> > * Pass --enable-fix-loongson2f-nop by default from debian/rules.
> 
> This enables it by default for all packages built with binutils?

Yes.  When this version of binutils is built using the
--enable-fix-loongson2f-nop compile-time option, then all packages
built using that binutils will include the NOP workaround (unless
-mnofix-loongson2f-nop is passed to the assembler).

One minor caveat, however: some bare (unfixed) NOPs are still included
in the C run-time library which is normally statically linked into
executables.  I guess we need to recompile gcc using this version of
binutils to take care of that issue.

> > I've also built binary packages for mipsel and placed them in
> > fencepost.gnu.org:~mhw/binutils-metad/
> 
> Fencepost.gnu.org/~mhw/binutils-metad/ offers me a bin, is that
> expected?

I'm not sure I understand the question, but if you're asking whether I
intentionally included mipsel binary packages in that directory, the
answer is yes.

> * The changes are made directly to the source tree, rather then as
> patches applied at package build time.

Ah yes, good point!  I've fixed this problem and put a new version of
everything (the new patch relative to lenny-backports, and new source
and mipsel binary packages) in:

fencepost.gnu.org:~mhw/binutils-metad1/

   Thanks,
     Mark