On Fri, Oct 23, 2020 at 14:08:25 +0200, Ard Biesheuvel wrote:
> Now that we implemented supported for the LoadFile2 protocol for initrd
> loading, there is no longer a need to pass the initrd parameters via
> the device tree. This means there is no longer a reason to update the
> device tree in the first place, and so we can ignore it entirely.
There is a change in behaviour here which I don't think matters, but
I'll call it out anyway:
If there was ever a kernel out there with an EFI stub that depended on
a chosen node existing in the DT, and the one provide by firmware did
not contain one, that setup would break from this *if* it didn't use
an initrd.
/
Leif
> The only remaining reason to deal with the devicetree is if we are
> using the 'devicetree' command to load one from disk, so tweak the
> logic in grub_fdt_install() to take that into account.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxx>
> ---
> grub-core/loader/arm64/linux.c | 22 ++++++++++----------
> grub-core/loader/efi/fdt.c | 7 +++++--
> 2 files changed, 16 insertions(+), 13 deletions(-)
>
> diff --git a/grub-core/loader/arm64/linux.c b/grub-core/loader/arm64/linux.c
> index 285422c7bd43..9e282b6660fe 100644
> --- a/grub-core/loader/arm64/linux.c
> +++ b/grub-core/loader/arm64/linux.c
> @@ -93,21 +93,21 @@ finalize_params_linux (void)
>
> void *fdt;
>
> - fdt = grub_fdt_load (GRUB_EFI_LINUX_FDT_EXTRA_SPACE);
> + /* Set initrd info */
> + if (initrd_start && initrd_end > initrd_start)
> + {
> + fdt = grub_fdt_load (GRUB_EFI_LINUX_FDT_EXTRA_SPACE);
>
> - if (!fdt)
> - goto failure;
> + if (!fdt)
> + goto failure;
>
> - node = grub_fdt_find_subnode (fdt, 0, "chosen");
> - if (node < 0)
> - node = grub_fdt_add_subnode (fdt, 0, "chosen");
> + node = grub_fdt_find_subnode (fdt, 0, "chosen");
> + if (node < 0)
> + node = grub_fdt_add_subnode (fdt, 0, "chosen");
>
> - if (node < 1)
> - goto failure;
> + if (node < 1)
> + goto failure;
>
> - /* Set initrd info */
> - if (initrd_start && initrd_end > initrd_start)
> - {
> grub_dprintf ("linux", "Initrd @ %p-%p\n",
> (void *) initrd_start, (void *) initrd_end);
>
> diff --git a/grub-core/loader/efi/fdt.c b/grub-core/loader/efi/fdt.c
> index ee9c5592c700..ab900b27d927 100644
> --- a/grub-core/loader/efi/fdt.c
> +++ b/grub-core/loader/efi/fdt.c
> @@ -85,13 +85,16 @@ grub_fdt_install (void)
> grub_efi_guid_t fdt_guid = GRUB_EFI_DEVICE_TREE_GUID;
> grub_efi_status_t status;
>
> + if (!fdt && !loaded_fdt)
> + return GRUB_ERR_NONE;
> +
> b = grub_efi_system_table->boot_services;
> - status = b->install_configuration_table (&fdt_guid, fdt);
> + status = b->install_configuration_table (&fdt_guid, fdt ?: loaded_fdt);
> if (status != GRUB_EFI_SUCCESS)
> return grub_error (GRUB_ERR_IO, "failed to install FDT");
>
> grub_dprintf ("fdt", "Installed/updated FDT configuration table @ %p\n",
> - fdt);
> + fdt ?: loaded_fdt);
> return GRUB_ERR_NONE;
> }
>
> --
> 2.17.1
>
