[PATCH] Set cpu explicitly in kernel compiles
Kumar Gala
kumar.gala at freescale.com
Sat May 7 01:47:14 EST 2005
On May 6, 2005, at 9:53 AM, Tom Rini wrote:
> On Fri, May 06, 2005 at 04:44:33PM +0200, Segher Boessenkool wrote:
> > >Well, say you are compiling for 405. You either need to have a gcc
> > >that was configured with --with-cpu=405, or you need to have hacked
> > >arch/ppc/Makefile to add -mcpu=405. In both cases the problem
> doesn't
> > >arise. It only arises if you have a biarch gcc4 that was
> configured
> > >without any --with-cpu=xxx option and is run without any -mcpu=xxx
> > >option.
> >
> > It happens for any installation where the default chosen by the GCC
> > used is not the -mcpu=XXX flag you need used for your kernel. Which
> > is a much more general statement than the biarch one. Most people
> just
> > get lucky, because they compile code with a compiler that is
> defaulted
> > for their target, and userland and kernel use (about) the same
> options
> > on most targets. Not so in biarch land (bleeech).
>
> Note that up until very recently (and just a bit before conflicting
> opcodes were added), no -mcpu=XXX was required. For example, I
> compiled
> a 44x kernel with a -mcpu=750 toolchain no problems shortly after Paul
> posted this. The only exception to this rule I can possibly think of
> is
> 85xx. But even that would be the "very recently" thing I mentioned as
> I know you can use an 82xx-set toolchain to build for 85xx.
>
> Having said that..
I do the same thing as well and the only issue I have is that 85xx
doesn't support strings thus the conditional we currently have for
-mstring.
- kumar
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