Re: [PATCH] remove target_os

[Christian Franke]

Javier Martín wrote:
> El mar, 27-01-2009 a las 20:56 +0100, Christian Franke escribió:
>   
> > Is building a bare 'no-OS' compiler supported by the upstream GCC sources?
> > Probably a too strict prerequisite for building GRUB.
> >     
>
> I can't vouch so for all possible environments, but I can say that
> "clean" no-OS targets like i386-pc-elf exist at least for x86 and x86_64
> (this last being added as of GCC 4.3.2). However, as I said, if
> -ffreestanding does not do its job of providing a "true" freestanding
> environment (i.e. without relying on _any_ external libraries or
> syscalls, as opposite to the usual hosted environment), a bug report
> should be posted.
>
>   

I haven't examined more recent gcc sources yet, the extra effect of 
-ffreestanding on 4.3.1 is a no-op if the program does not use main().

How do those no-OS targets handle the platform independent libgcc 
functions, e.g. __divdi3 which is used for 64bit integer division at 
least on i386 ? Is a no-OS version of libgcc provided or should the 
programmer handle these cases ?

Christian