Re: 64bit startup

[Samuel Thibault]

Hello,

Flávio Cruz, le dim. 05 nov. 2023 23:17:49 -0500, a ecrit:
> On Tue, Oct 31, 2023 at 9:14 PM Samuel Thibault <[1]samuel.thibault@gnu.org>
> wrote:
> 
> > Realizing only now by reading the __mach_msg_destroy assembly...
> >
> >     unsigned int        msgt_inline : 1,
> >                         msgt_longform : 1,
> >                         msgt_deallocate : 1,
> >                         msgt_name : 8,
> >                         msgt_size : 16,
> >                         msgt_unused : 5;
> >
> > This field ordering makes reading them overly complex... It'll be a pain
> > to rebootstrap, but perhaps we do want to put msgt_size and msgt_name
> > first?
> 
> I only moved msgt_size to the end of the struct

Ok, so we can as well align fields to make bit mangling simpler.

> However, I wonder if it would be simpler to just ask the user land to
> pass port names using the following struct:
> 
> #ifdef KERNEL
> union mach_rpc_port {
>    mach_port_name_t name;
>    mach_port_t kernel_port;
> };
> #else
> struct mach_rpc_port {
>    mach_port_name_t name;
>    int unused;
> };
> #endif
> 
> It would make the kernel simpler since no message resizing is
> necessary

I was thinking about this suggestion today, and I think that'll be
better for the long run indeed. There are questions about holes being
uninitialized, but:

> and most of the code using this would be MiG generated.

indeed.

I'm almost done with the ground set of Debian packages. Will wait until
this is settled before building the hurd-amd64 Debian world :)

Samuel