Re: Grub for ia64 - function descriptors

[tgingold]

Selon Hollis Blanchard <address@hidden>:

>
> On Mon, 02 Oct 2006 08:31:10 +0200, address@hidden said:
> > Quoting Hollis Blanchard <address@hidden>:
[...]
> > > > >I assume IA64 is similar here, and given that, a
> > > > > module_jump function implemented in assembly by each architecture
> would
> > > > > solve this problem.
> > > > I'd prefer modules to export pointers. Seems to be easier to deal.
> > >
> > > I don't know what you mean; please elaborate (with pseudo-code if
> > > possible).
> >
> > I'd propose modules export struct grub_dl.  This struct contains init and
> > fini
> > functions pointers.
> > Getting the address of a data structure is much more portable.
> > Dealing with function pointers would be a matter of the relocator.
>
> It looks like this is only done twice in the current code: mod->init and
> mod->fini. Wouldn't it be easy to do this:
> --- kern/dl.c   28 May 2006 23:01:43 -0000      1.12
> +++ kern/dl.c   3 Oct 2006 02:15:51 -0000
> @@ -380,9 +380,9 @@ grub_dl_resolve_symbols (grub_dl_t mod,
>               return grub_errno;
>
>           if (grub_strcmp (name, "grub_mod_init") == 0)
> -           mod->init = (void (*) (grub_dl_t)) sym->st_value;
> +           mod->init = grub_dl_arch_func (sym->st_value);
>           else if (grub_strcmp (name, "grub_mod_fini") == 0)
> -           mod->fini = (void (*) (void)) sym->st_value;
> +           mod->fini = grub_dl_arch_func (sym->st_value);
>           break;
>
>         case STT_SECTION:
To create descriptor, grub_dl_arch_func have to grub_malloc memory.  How to free
it ?

I always prefer to use static memory when I can do that: code is smaller and
safer.  That's the reason why I'd prefer to have struct grub_dl declared static.
Of course this is just my opinion.

Tristan.