* frame_table initialisation
@ 2007-02-26 14:45 PUCCETTI Armand
2007-02-26 16:02 ` Keir Fraser
0 siblings, 1 reply; 2+ messages in thread
From: PUCCETTI Armand @ 2007-02-26 14:45 UTC (permalink / raw)
To: xen-devel
It is unclear for me how variable frame_table is initialised:
1. According to function __start_xen:
Variable frame_table is initialised by __start_xen -> init_frametable.
but
2. some lines before in __start_xen, this variable is referenced by
function map_pages_to_xen -> virt_to_xen_l2 -> alloc_xen_pagetable ->
mfn_to_page.
What should the value of frame_table be there?
Do I miss some pre-initialisation(s)?
Armand
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: frame_table initialisation
2007-02-26 14:45 frame_table initialisation PUCCETTI Armand
@ 2007-02-26 16:02 ` Keir Fraser
0 siblings, 0 replies; 2+ messages in thread
From: Keir Fraser @ 2007-02-26 16:02 UTC (permalink / raw)
To: PUCCETTI Armand, xen-devel
On 26/2/07 14:45, "PUCCETTI Armand" <armand.puccetti@cea.fr> wrote:
> 2. some lines before in __start_xen, this variable is referenced by
> function map_pages_to_xen -> virt_to_xen_l2 -> alloc_xen_pagetable ->
> mfn_to_page.
> What should the value of frame_table be there?
>
> Do I miss some pre-initialisation(s)?
The fact that frame_table is not initialised here (and hence will be NULL)
doesn't actually matter, since the result of mfn_to_page() is only actually
used as a value to page_to_mfn(). And page_to_mfn(mfn_to_page(m))==m for any
(constant) value of frame_table.
This code could be clearer I'll admit. It probably makes sense for
alloc_xen_pagetable to return an MFN rather than a page_info pointer.
-- Keir
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2007-02-26 16:02 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-02-26 14:45 frame_table initialisation PUCCETTI Armand
2007-02-26 16:02 ` Keir Fraser
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.