Re: Some basic questions from a novice !

[Jeff Johnston <jjohnstn at redhat dot com>]

Frank, please read the short FAQ (no. 5) on the newlib website: 
http://sources.redhat.com/newlib to understand how multilib 
functionality works in conjunction with gcc to automatically select the 
right target libraries for an application based on the compile options 
(if you haven't already).

In the case where there is a processor/option combination not being 
handled by gcc multilibs, you should look into adding them to gcc.  You 
need to talk to the folks on the gcc list about how best to do this.

-- Jeff J.

Frank Juergen-r58616 wrote:
> Yep, I know this works but I think this work only in case your selected core and the default core are similar. 
> I use a 3.4 version of gcc and a this version compiled the libraries for the following version 
>
>
> mycross-gcc --print-multi-libs
>
> .;
> mpc7400;@mcpu=7400
> nof;@msoft-float
> le;@mlittle
> no-spe/no-abi-spe/no-isel;@mspe=no@mabi=no-spe@misel=no
> no-spe/no-abi-spe/no-isel/le;@mspe=no@mabi=no-spe@misel=no@mlittle
> nof/le;@msoft-float@mlittle
> mpc7400/nof;@mcpu=7400@msoft-float
> mpc7400/le;@mcpu=7400@mlittle
> mpc7400/nof/le;@mcpu=7400@msoft-float@mlittle
> mpc7400/altivec/abi-altivec;@mcpu=7400@maltivec@mabi=altivec
> mpc7400/altivec/abi-altivec/le;@mcpu=7400@maltivec@mabi=altivec@mlittle
>
> So if you use this with setup with the 603 it works, but if you try to use a core with a subset of instruction set from the normal PPC, you can't use this setup.
>
> I dig in the internet and in the gcc directories and I think the key is the multilib functionality.
>
> 	Juergen
>
>
>
> -----Original Message-----
> From: Amir Bukhari [mailto:ufz6@rz.uni-karlsruhe.de] 
> Sent: Dienstag, 3. Januar 2006 13:03
> To: Frank Juergen-r58616
> Subject: RE: Some basic questions from a novice !
>
>  
>
> > I want to use GCC ( powerpc-eabi ) with newlib.
> > How it is possible to use diff. powerpc cores which has diff. 
> > instructions sets (or subset) for example I want to compile a program 
> > for the 603e, PPC405 and for the 8540. With and without 
> > hardware-floating point. What is the best way to do this ? I try the 
> > CFLAGS_FOR_TARGET = "-mhard-float -mcpu=603e", but if I set this 
> > environment variable I can't compile newlib anymore !
> > Finally, I want my own newlib versions for every core ... any hints 
> > and ideas ?
>
>
> You don't need to specify which powerpc cpu you should use with newlib. You just need to compile newlib with default options and use "-mcpu=603e" when you compile your program and link it with newlib. I use this way and it work.
>
>
> -Amir