Re: 64bit startup

[Sergey Bugaev]

On Wed, Aug 9, 2023 at 12:20 PM Samuel Thibault <samuel.thibault@gnu.org> wrote:
> Sergey Bugaev, le mer. 09 août 2023 12:12:29 +0300, a ecrit:
> > It should just reuse whatever memory the bootloader has already loaded
> > the module into, no need to copy it out anywhere.
>
> (my guess is that it's not so simple because possibly we somehow get rid
> of the memory allocated for modules, otherwise we'd get stuck with that
> piece of memory area that we cannot reuse for other system memory uses)

We do that yeah (see free_bootstrap_pages in kern/bootstrap.h);

there should be a way to turn that off. For now I'm thinking I'll just
set mod_end = mod_start = 0 for the bootstrap module that I take pages
from; later we may do something more advanced like making each
bootscript command free its module pages if it doesn't end up using
them, as opposed to freeing all the modules later in single loop. I'd
expect all pages to basically always get used, so we'd never actually
have to free them at boot time.

Sergey