Re: Possible GCC contamination of Linux

Horst von Brand (vonbrand@inf.utfsm.cl)
Wed, 22 Sep 1999 17:37:24 -0400


"Richard B. Johnson" <root@chaos.analogic.com> said:
> On Wed, 22 Sep 1999, Horst von Brand wrote:
> > "Richard B. Johnson" <root@chaos.analogic.com> said:
> > > On Wed, 22 Sep 1999, Artur Skawina wrote:
> > > > Kurt Garloff wrote:

> > > > > a patch which adds -fno-builtins to the Makefile and makes the
> > > > > abs() work.

> > > > why?

> > > So you can compile a i386 or i486 kernel with a 'C' compiler that was
> > > built on a i686 machine. It took me a week to find the reason why
> > > a kernel, configured to run on a 486 (or even 386) would crash on
> > > the boot of a 486.

> > If the compiler gives you i686 instructions for a i486 target that you
> > correctly specified, then the compiler is broken, pure and simple. Are you
> > sure the Makefiles do set the target right? What gcc version are you using?
> > Did you report the problem to the egcs folks?

> I've been through this too many times already. The makefile is set up
> right, the .config is set up right. I have used three versions of
> the gcc compiler, never egcs.
>
> gcc 2.7.2, gcc 2.7.3, and gcc 2.8.1

Then those are broken, as I stated. Note that all of them are obsolete and
non-maintained.

[...]

> My suggestion was to not use any built-ins in the kernel. In other
> words, if the kernel requires code it should be generated by kernel
> source, not C-compiler source.

Yep. No coding in C, only assembler.

-- 
Dr. Horst H. von Brand                       mailto:vonbrand@inf.utfsm.cl
Departamento de Informatica                     Fono: +56 32 654431
Universidad Tecnica Federico Santa Maria              +56 32 654239
Casilla 110-V, Valparaiso, Chile                Fax:  +56 32 797513

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