Re: Warnings in kern/dl.c

[Bean]

On Fri, Jul 18, 2008 at 1:38 PM, Pavel Roskin <address@hidden> wrote:
> Hello, Bean!
>
> I think this change from the x86_64 EFI patch should be reverted:
>
>        * kern/dl.c (GRUB_CPU_SIZEOF_VOID_P): Changed to
>         GRUB_TARGET_SIZEOF_VOID_P.
>
> It causes warnings when compiling grub-emu on x64_64 for i386:
>
> kern/dl.c: In function 'grub_dl_resolve_symbols':
> kern/dl.c:357: warning: cast from pointer to integer of different size
> kern/dl.c:368: warning: cast from pointer to integer of different size
> kern/dl.c:370: warning: cast to pointer from integer of different size
> kern/dl.c:376: warning: cast from pointer to integer of different size
> kern/dl.c:378: warning: cast to pointer from integer of different size
> kern/dl.c:382: warning: cast to pointer from integer of different size
> kern/dl.c:384: warning: cast to pointer from integer of different size
> kern/dl.c:389: warning: cast from pointer to integer of different size
>
> I'm really close to eliminating all warnings, and such additions are not
> making me happy.
>
> The warnings could be suppressed somehow, but I don't think it's the right
> thing to do.  64-bit grub-emu cannot load 32-bit modules (and vice versa).
>  64-bit grub-emu could load 64-bit modules in principle, although we don't
> compile them.   We could compile special grub-emu modules, but I would not
> spend any serious effort on it.
>
> Anyway, I would prefer that we compile support for loading 64-bit modules
> and possibly catch some useful warnings relevant to 64-bit platforms (even
> if our target is 32-bit).  It's better than to "implement"
> cross-architecture loading of modules that would not work anyway by filling
> the code with casts.  It's better than to tolerate several warnings.  Either
> increases the risk that a real warning would be missed.

Hi,

This is used for cross complication. For example, when we compile
x86_64-efi in i386, the host system is i386, but target system is
64-bit. I have been compiling the efi image using this method, there
is no problem.

As for grub-emu, does it matter if we can't load external modules ?
The import module are all static linked. Besides, some of the modules
depend on real mode component, so we can't load them anyway.

-- 
Bean