Hi Samuel,
comments are within the text!
Am Mittwoch, 13. Februar 2008 schrieb Samuel Thibault:
> Hello,
>
> Dietmar Hahn, le Wed 13 Feb 2008 11:53:59 +0100, a écrit :
> > Am Dienstag, 12. Februar 2008 schrieb Samuel Thibault:
> > > Is there a reason for using -mfixed-range=f2-f5,f12-f15,f32-f127
> > > when compiling Mini-OS? Is it really needed since it doesn't
> > > have a user-land? (though I guess some support would be needed in
> > > switch_context for instance)
> >
> > To handle this in a clean way the trap_frame has to be expanded and some
> > fp registers have to stored/restored in trap handling.
>
> Ok. Would this be needed in order to be able to use libgcc.a?
No, both things are independent from each other.
>
> > > Then, are there other reasons for using __*div/di*.S instead of just
> > > linking with libgcc?
> >
> > It's possible to use libgcc.a but the flag -mconstant-gp has to be
> > removed from the mini-os makefiles and a clean way to add libgcc.a is
> > needed.
>
> Something like the attached patch?
>
> Actually I'm asking because for other purpose, I would need __divdi on
> x86_32, and using libgcc.a is a really simple solution.
Ok I understand - the attached patch runs fine.
> > By the way current mini-os crashed with Unaligned Reference.
> > A small change is needed:
> > static void maybe_split(struct xmalloc_hdr *hdr, size_t size, size_t
> > block) {
> > struct xmalloc_hdr *extra;
> > - size_t leftover = block - size;
> > + size_t leftover;
> > +#if defined(__ia64__)
> > + size = (size +7 ) & ~7; /* alignment needed on 8 byte boundary. */
> > +#endif
> > + leftover = block - size;
>
> Does the following patch work?
>
> diff -r 3cc84775d725 extras/mini-os/lib/xmalloc.c
> --- a/extras/mini-os/lib/xmalloc.c Tue Feb 12 17:04:32 2008 +0000
> +++ b/extras/mini-os/lib/xmalloc.c Wed Feb 13 12:03:52 2008 +0000
> @@ -62,10 +62,19 @@ struct xmalloc_pad
> size_t hdr_size;
> };
>
> +/* Return size, increased to alignment with align. */
> +static inline size_t align_up(size_t size, size_t align)
> +{
> + return (size + align - 1) & ~(align - 1);
> +}
> +
> static void maybe_split(struct xmalloc_hdr *hdr, size_t size, size_t
> block) {
> struct xmalloc_hdr *extra;
> - size_t leftover = block - size;
> + size_t leftover;
> + size = align_up(size, __alignof__(struct xmalloc_hdr));
> + size = align_up(size, __alignof__(struct xmalloc_pad));
> + leftover = block - size;
>
> /* If enough is left to make a block, put it on free list. */
> if ( leftover >= (2 * (sizeof(struct xmalloc_hdr) + sizeof(struct
> xmalloc_pad))) ) @@ -98,12 +107,6 @@ static struct xmalloc_hdr
> *xmalloc_new_p
> maybe_split(hdr, size, PAGE_SIZE);
>
> return hdr;
> -}
> -
> -/* Return size, increased to alignment with align. */
> -static inline size_t align_up(size_t size, size_t align)
> -{
> - return (size + align - 1) & ~(align - 1);
> }
>
> /* Big object? Just use the page allocator. */
>
> Samuel
This patch works fine too!
Dietmar.
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