[PATCH v2 8/8] efi_loader: load distro dtb in bootmgr

[Ilias Apalodimas]

On Tue, 28 May 2024 at 17:43, Heinrich Schuchardt
<heinrich.schuchardt at canonical.com> wrote:
>
> If no device-tree is specified, try to load a device-tree from the boot
> device use the $fdtfile concatenated to either of the paths '/dtb/', '/',
> '/dtb/current/'.
>
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> ---
> v2:
>         no change
> ---
>  include/efi_loader.h         |  2 ++
>  lib/efi_loader/efi_bootmgr.c | 13 +++++++++--
>  lib/efi_loader/efi_fdt.c     | 44 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 57 insertions(+), 2 deletions(-)
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index ab7bed22971..6c993e1a694 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -1205,4 +1205,6 @@ efi_status_t efi_load_option_dp_join(struct efi_device_path **dp,
>
>  int efi_get_distro_fdt_name(char *fname, int size, int seq);
>
> +void efi_load_distro_fdt(void **fdt, efi_uintn_t *fdt_size);
> +
>  #endif /* _EFI_LOADER_H */
> diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> index b08d6e97ea3..68440542a37 100644
> --- a/lib/efi_loader/efi_bootmgr.c
> +++ b/lib/efi_loader/efi_bootmgr.c
> @@ -1249,7 +1249,8 @@ efi_status_t efi_bootmgr_run(void *fdt)
>         efi_handle_t handle;
>         void *load_options;
>         efi_status_t ret;
> -       void *fdt_lo;
> +       void *fdt_lo, *fdt_distro = NULL;
> +       efi_uintn_t fdt_size;
>
>         /* Initialize EFI drivers */
>         ret = efi_init_obj_list();
> @@ -1269,6 +1270,10 @@ efi_status_t efi_bootmgr_run(void *fdt)
>                         return ret;
>                 if (fdt_lo)
>                         fdt = fdt_lo;
> +               if (!fdt) {
> +                       efi_load_distro_fdt(&fdt_distro, &fdt_size);
> +                       fdt = fdt_distro;
> +               }
>         }
>
>         /*
> @@ -1277,8 +1282,12 @@ efi_status_t efi_bootmgr_run(void *fdt)
>          */
>         ret = efi_install_fdt(fdt);
>
> -       if (!IS_ENABLED(CONFIG_GENERATE_ACPI_TABLE))
> +       if (!IS_ENABLED(CONFIG_GENERATE_ACPI_TABLE)) {
>                 free(fdt_lo);
> +               if (fdt_distro)
> +                       efi_free_pages((uintptr_t)fdt_distro,
> +                                      efi_size_in_pages(fdt_size));
> +       }
>
>         if (ret != EFI_SUCCESS) {
>                 if (EFI_CALL(efi_unload_image(handle)) == EFI_SUCCESS)
> diff --git a/lib/efi_loader/efi_fdt.c b/lib/efi_loader/efi_fdt.c
> index 0edf0c1e2fc..86ba00c2bdd 100644
> --- a/lib/efi_loader/efi_fdt.c
> +++ b/lib/efi_loader/efi_fdt.c
> @@ -71,3 +71,47 @@ int efi_get_distro_fdt_name(char *fname, int size, int seq)
>
>         return 0;
>  }
> +
> +/**
> + * efi_load_distro_fdt() - load distro device-tree
> + *
> + * @fdt:       on return device-tree, must be freed via efi_free_pages()
> + * @fdt_size:  buffer size
> + */
> +void efi_load_distro_fdt(void **fdt, efi_uintn_t *fdt_size)
> +{
> +       struct efi_device_path *rem, *dp;
> +       efi_status_t  ret;
> +       efi_handle_t device;
> +
> +       *fdt = NULL;
> +
> +       dp = efi_get_dp_from_boot(NULL);
> +       if (!dp)
> +               return;
> +       device = efi_dp_find_obj(dp, NULL, &rem);
> +       ret = efi_search_protocol(device, &efi_simple_file_system_protocol_guid,
> +                                 NULL);
> +       if (ret != EFI_SUCCESS)
> +               goto err;
> +       memcpy(rem, &END, sizeof(END));
> +
> +       /* try the various available names */
> +       for (int seq = 0; ; ++seq) {
> +               struct efi_device_path *file;
> +               char buf[255];
> +
> +               if (efi_get_distro_fdt_name(buf, sizeof(buf), seq))
> +                       break;
> +               file = efi_dp_from_file(dp, buf);
> +               if (!file)
> +                       break;
> +               ret = efi_load_image_from_path(true, file, fdt, fdt_size);
> +               efi_free_pool(file);
> +               if (ret == EFI_SUCCESS)
> +                       break;
> +       }
> +
> +err:
> +       efi_free_pool(dp);
> +}
> --
> 2.43.0
>

Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>