[RFC PATCH 4/5] bootefi: Call the EVT_FT_FIXUP event handler

[Sughosh Ganu]

On Sat, 26 Aug 2023 at 15:57, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 8/26/23 11:06, Sughosh Ganu wrote:
> > The bootefi command passes the devicetree to the kernel through the
> > EFI config table. Call the event handlers for fixing the devicetree
> > before jumping into the kernel. This removes any devicetree nodes
> > and/or properties that are specific only to U-Boot, and are not to be
> > passed to the OS.
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> > ---
> >   cmd/bootefi.c | 18 ++++++++++++++++++
> >   1 file changed, 18 insertions(+)
> >
> > diff --git a/cmd/bootefi.c b/cmd/bootefi.c
> > index f73d6eb0e2..c359a46ec4 100644
> > --- a/cmd/bootefi.c
> > +++ b/cmd/bootefi.c
> > @@ -237,6 +237,23 @@ static void *get_config_table(const efi_guid_t *guid)
> >       return NULL;
> >   }
> >
> > +/**
> > + * event_notify_dt_fixup() - call ft_fixup event
> > + *
> > + * @fdt:     address of the device tree to be passed to the kernel
> > + *           through the configuration table
> > + * Return:   None
> > + */
> > +static void event_notify_dt_fixup(void *fdt)
> > +{
> > +     int ret;
> > +     struct event_ft_fixup fixup = {0};
> > +
> > +     fixup.tree.fdt = fdt;
> > +     ret = event_notify(EVT_FT_FIXUP, &fixup, sizeof(fixup));
> > +     if (ret)
> > +             printf("Error: %d: FDT Fixup event failed\n", ret);
> > +}
> >   #endif /* !CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE) */
> >
> >   /**
> > @@ -318,6 +335,7 @@ efi_status_t efi_install_fdt(void *fdt)
> >       efi_carve_out_dt_rsv(fdt);
> >
> >       efi_try_purge_kaslr_seed(fdt);
> > +     event_notify_dt_fixup(fdt);
>
> The event is already triggered in image_setup_libfdt(). Don't trigger it
> twice.

The reason I put an explicit event_notify call is because the
image_setup_libfdt() call only calls the ft_fixup handlers if the
livetree is not active. So the fixup handlers would not be called on
platforms that enable livetree. Although I'm not sure if livetree
should be disabled before the ft fixup has to happen, or platforms
that need ft fixup should not enable OF_LIVE. Disabling the livetree
is not happening now, so I am not sure how the fixup event should work
on platforms which have OF_LIVE enabled.

-sughosh

>
> Best regards
>
> Heinrich
>
> >
> >       if (CONFIG_IS_ENABLED(EFI_TCG2_PROTOCOL_MEASURE_DTB)) {
> >               ret = efi_tcg2_measure_dtb(fdt);
>