[PATCH 6/7] WIP: efi: Allow helloworld to exit boot services

[Ilias Apalodimas]

Hi Simon,

On Wed, 22 Nov 2023 at 00:10, Simon Glass <sjg at chromium.org> wrote:
>
> Hi Heinrich,
>
> On Tue, 21 Nov 2023 at 10:17, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
> >
> > On 11/21/23 12:35, Simon Glass wrote:
> > > This allows testing of the exit_boot_services call, providing more
> > > coverage of the EFI bootmeth.
> > >
> > > Signed-off-by: Simon Glass <sjg at chromium.org>
> >
> > I would prefer to keep helloworld.efi benign.
> >
> > Please, create a new EFI binary for testing ExitBootServices().
>
> Eek...isn't helloworld already used in tets?\

Yes, but calling exitboot services from it means we need to be really
careful when/how we call it, since once that app runs the boottime
services along with any attached disks will disappear.
Instead having a single EFI app that calls that and then tests for any
runtime services is more scalable

Thanks
/Ilias
>
> >
> > > ---
> > >
> > >   lib/efi_loader/helloworld.c | 36 +++++++++++++++++++++++++++++++++++-
> > >   1 file changed, 35 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/lib/efi_loader/helloworld.c b/lib/efi_loader/helloworld.c
> > > index 1135d3a3c37e..1fb5fb5a62f2 100644
> > > --- a/lib/efi_loader/helloworld.c
> > > +++ b/lib/efi_loader/helloworld.c
> > > @@ -206,6 +206,26 @@ efi_status_t EFIAPI efi_main(efi_handle_t handle,
> > >                       (con_out, u"Cannot open loaded image protocol\r\n");
> > >               goto out;
> > >       }
> > > +
> > > +     {
> > > +             ulong ptr = (ulong)loaded_image;
> > > +             u16 str[80];
> > > +             int i;
> > > +
> > > +             for (i = 0; i < 8; i++) {
> > > +                     uint digit = (ptr >> ((7 - i) * 4)) & 0xf;
> > > +
> > > +                     if (digit > 9)
> > > +                             digit = 'a' + digit - 10;
> > > +                     else
> > > +                             digit += '0';
> > > +                     str[i] = digit;
> > > +             }
> > > +             str[i] = 0;
> > > +             con_out->output_string(con_out, str);
> > > +             con_out->output_string(con_out, u"\n");
> > > +     }
> > > +
> > >       print_load_options(loaded_image);
> > >
> > >       /* Get the device path to text protocol */
> > > @@ -243,7 +263,21 @@ efi_status_t EFIAPI efi_main(efi_handle_t handle,
> > >               goto out;
> > >
> > >   out:
> > > -     boottime->exit(handle, ret, 0, NULL);
> > > +     /*
> > > +      * TODO: Use vendor string to decide whether to call exit-boot-services
> > > +      */
> > > +     efi_uintn_t map_size = 0;
> > > +     efi_uintn_t map_key;
> > > +     efi_uintn_t desc_size;
> > > +     u32 desc_version;
> > > +
> > > +     ret = boottime->get_memory_map(&map_size, NULL, &map_key, &desc_size,
> > > +                                    &desc_version);
> > > +     con_out->output_string(con_out, u"Exiting boot sevices\n");
> > > +
> > > +     boottime->exit_boot_services(handle, map_key);
> > > +
> > > +     ret = boottime->exit(handle, ret, 0, NULL);
> >
> > After ExitBootServices() you must not call boot services.
> >
> > Call runtime->reset_system(EFI_RESET_COLD, EFI_SUCCESS, 0, NULL) instead.
>
> OK, will do. That will be ignored by sandbox, right?
>
> For now this is just a hack to try to resolve the problem mentioned.
>
> Regards,
> Simon