[PATCH v9 7/9] efi_loader: support boot from URI device path

Ilias Apalodimas ilias.apalodimas at linaro.org
Thu Nov 2 12:02:55 CET 2023


Hi Kojima-san


> +
> +/**
> + * try_load_default_file() - try to load the default file
> + *
> + * Search the device having EFI_SIMPLE_FILE_SYSTEM_PROTOCOL,
> + * then try to load with the default boot file(e.g. EFI/BOOT/BOOTAA64.EFI).
> + *
> + * @dev                        pointer to the UCLASS_BLK or UCLASS_PARTITION udevice
> + * @image_handle:      pointer to handle for newly installed image
> + * Return:             status code
> + */
> +static efi_status_t try_load_default_file(struct udevice *dev,
> +                                         efi_handle_t *image_handle)
> +{
> +       efi_status_t ret;
> +       efi_handle_t handle;
> +       struct efi_handler *handler;
> +       struct efi_device_path *file_path;
> +       struct efi_device_path *device_path;
> +
> +       if (dev_tag_get_ptr(dev, DM_TAG_EFI, (void **)&handle)) {
> +               log_warning("DM_TAG_EFI not found\n");
> +               return EFI_INVALID_PARAMETER;
> +       }
> +
> +       ret = efi_search_protocol(handle,
> +                                 &efi_simple_file_system_protocol_guid, &handler);
> +       if (ret != EFI_SUCCESS)
> +               return ret;
> +
> +       ret = EFI_CALL(bs->open_protocol(handle, &efi_guid_device_path,
> +                                        (void **)&device_path, efi_root, NULL,
> +                                        EFI_OPEN_PROTOCOL_GET_PROTOCOL));
> +       if (ret != EFI_SUCCESS)
> +               return ret;
> +
> +       file_path = expand_media_path(device_path);
> +       ret = EFI_CALL(efi_load_image(true, efi_root, file_path, NULL, 0,
> +                                     image_handle));
> +       efi_free_pool(file_path);
> +
> +       return ret;
> +}
> +
> +/**
> + * load_default_file_from_blk_dev() - load the default file
> + *
> + * @blk                pointer to the UCLASS_BLK udevice
> + * @handle:    pointer to handle for newly installed image
> + * Return:     status code
> + */
> +static efi_status_t load_default_file_from_blk_dev(struct udevice *blk,
> +                                                  efi_handle_t *handle)
> +{
> +       efi_status_t ret;
> +       struct udevice *partition;
> +
> +       /* image that has no partition table but a file system */
> +       ret = try_load_default_file(blk, handle);
> +       if (ret == EFI_SUCCESS)
> +               return ret;
> +
> +       /* try the partitions */
> +       device_foreach_child(partition, blk) {
> +               enum uclass_id id;
> +
> +               id = device_get_uclass_id(partition);
> +               if (id != UCLASS_PARTITION)
> +                       continue;
> +
> +               ret = try_load_default_file(partition, handle);
> +               if (ret == EFI_SUCCESS)
> +                       return ret;
> +       }
> +
> +       return EFI_NOT_FOUND;
> +}
> +
> +/**
> + * efi_bootmgr_release_ramdisk() - release ramdisk resource
> + *
> + * Return:             status code
> + */
> +efi_status_t efi_bootmgr_release_ramdisk(void)
> +{
> +       efi_status_t ret = EFI_SUCCESS;
> +
> +       if (ramdisk_blk_dev) {
> +               ret = efi_add_memory_map(image_addr, image_size,
> +                                        EFI_CONVENTIONAL_MEMORY);
> +               if (ret != EFI_SUCCESS)
> +                       log_err("Reclaiming memory failed\n");
> +
> +               if (blkmap_destroy(ramdisk_blk_dev->parent)) {
> +                       log_err("Destroying blkmap failed\n");
> +                       ret = EFI_DEVICE_ERROR;
> +               }
> +
> +               ramdisk_blk_dev = NULL;
> +       }
> +
> +       return ret;
> +}
> +
> +/**
> + * efi_bootmgr_image_return_notify() - return to efibootmgr callback
> + *
> + * @event:     the event for which this notification function is registered
> + * @context:   event context - not used in this function
> + */
> +static void EFIAPI efi_bootmgr_image_return_notify(struct efi_event *event,
> +                                                  void *context)
> +{
> +       efi_status_t ret;
> +
> +       EFI_ENTRY("%p, %p", event, context);
> +       ret = efi_bootmgr_release_ramdisk();
> +       EFI_EXIT(ret);
> +}
> +
> +/**
> + * try_load_from_uri_path() - Handle the URI device path
> + *
> + * @uridp:     uri device path
> + * @lo_label:  label of load option
> + * @handle:    pointer to handle for newly installed image
> + * Return:     status code
> + */
> +static efi_status_t try_load_from_uri_path(struct efi_device_path_uri *uridp,
> +                                          u16 *lo_label,
> +                                          efi_handle_t *handle)
> +{
> +       char *s;
> +       int err;
> +       int uri_len;
> +       efi_status_t ret;
> +       struct udevice *blk;
> +       struct efi_event *event = NULL;
> +
> +       s = env_get("loadaddr");
> +       if (!s) {
> +               log_err("Error: loadaddr is not set\n");
> +               return EFI_INVALID_PARAMETER;
> +       }
> +       image_addr = hextoul(s, NULL);
> +       err = wget_with_dns(image_addr, uridp->uri);
> +       if (err < 0)
> +               return EFI_INVALID_PARAMETER;
> +       image_size = env_get_hex("filesize", 0);
> +       if (!image_size)
> +               return EFI_INVALID_PARAMETER;
> +
> +       /*
> +        * If the file extension is ".iso" or ".img", mount it and try to load
> +        * the default file.
> +        * If the file is PE-COFF image, load the downloaded file.
> +        */
> +       uri_len = strlen(uridp->uri);
> +       if (!strncmp(&uridp->uri[uri_len - 4], ".iso", 4) ||
> +           !strncmp(&uridp->uri[uri_len - 4], ".img", 4)) {
> +               blk = mount_image(lo_label, image_addr, image_size);
> +               if (!blk)
> +                       return EFI_LOAD_ERROR;
> +
> +               ret = load_default_file_from_blk_dev(blk, handle);
> +               if (ret != EFI_SUCCESS) {
> +                       log_info("Cannot boot from downloaded image\n");
> +                       goto iso_error;
> +               }
> +
> +               ret = efi_create_event(EVT_NOTIFY_SIGNAL, TPL_CALLBACK,
> +                                      efi_bootmgr_image_return_notify, NULL,
> +                                      &efi_guid_event_group_return_to_efibootmgr, &event);
> +               if (ret != EFI_SUCCESS) {
> +                       log_err("Creating event failed\n");
> +                       goto iso_error;
> +               }
> +
> +               /*
> +                * TODO: expose the ramdisk to OS.
> +                * Need to pass the ramdisk information by the architecture-specific
> +                * methods such as 'pmem' device-tree node.
> +                */
> +               ret = efi_add_memory_map(image_addr, image_size,
> +                                        EFI_RESERVED_MEMORY_TYPE);
> +               if (ret != EFI_SUCCESS) {
> +                       log_err("Memory reservation failed\n");
> +                       goto iso_error;
> +               }
> +
> +               ramdisk_blk_dev = blk;
> +       } else if (efi_check_pe((void *)image_addr, image_size, NULL) == EFI_SUCCESS) {
> +               efi_handle_t mem_handle = NULL;
> +               struct efi_device_path *file_path;
> +
> +               file_path = efi_dp_from_mem(EFI_RESERVED_MEMORY_TYPE,
> +                                           (uintptr_t)image_addr, image_size);
> +               ret = efi_install_multiple_protocol_interfaces(
> +                       &mem_handle, &efi_guid_device_path, file_path, NULL);
> +               if (ret != EFI_SUCCESS)
> +                       return ret;
> +
> +               ret = EFI_CALL(efi_load_image(false, efi_root, file_path,
> +                                             (void *)image_addr, image_size,
> +                                             handle));
> +       } else {
> +               log_err("Error: file type is not supported\n");
> +               return EFI_UNSUPPORTED;
> +       }

This is a bit confusing to read overall.  It works fine though so I
suggest renaming load_default_file_from_blk_dev to
prepare_loaded_image().  That function can mount the image, reserve
memory and return the file path

The code for both efi apps and iso images would look like this

 if (!strncmp(&uridp->uri[uri_len - 4], ".iso", 4) ||
      !strncmp(&uridp->uri[uri_len - 4], ".img", 4)) {
          prepare_loaded_image()
          efi_create_event()
else if (efi_check_pe((void *)image_addr, image_size, NULL) == EFI_SUCCESS) {
      file_path = efi_dp_from_mem(EFI_RESERVED_MEMORY_TYPE,
                                              (uintptr_t)image_addr,
image_size);
                  ret = efi_install_multiple_protocol_interfaces(
                          &mem_handle, &efi_guid_device_path,
file_path, NULL);
                  if (ret != EFI_SUCCESS)
                          return ret;
} else {
   log_err("Error: file type is not supported\n");
   return EFI_UNSUPPORTED;
}

ret = EFI_CALL(efi_load_image(false, efi_root, file_path,
                                                (void *)image_addr,
image_size,
                                                handle));

.....


IOW the if/else cases prepare the DP for you and reserve any needed
memory.  Once that's done you load the image from a single location

Thanks
/Ilias


> +
> +       return ret;
> +
> +iso_error:
> +       if (blkmap_destroy(blk->parent))
> +               log_err("Destroying blkmap failed\n");
> +       if (event)
> +               EFI_CALL(bs->close_event(event));
> +       return ret;
> +}
> +
>  /**
>   * try_load_entry() - try to load image for boot option
>   *
> @@ -211,6 +471,14 @@ static efi_status_t try_load_entry(u16 n, efi_handle_t *handle,
>                 if (EFI_DP_TYPE(lo.file_path, MEDIA_DEVICE, FILE_PATH)) {
>                         /* file_path doesn't contain a device path */
>                         ret = try_load_from_short_path(lo.file_path, handle);
> +               } else if (EFI_DP_TYPE(lo.file_path, MESSAGING_DEVICE, MSG_URI)) {
> +                       if (IS_ENABLED(CONFIG_EFI_HTTP_BOOT))
> +                               ret = try_load_from_uri_path(
> +                                       (struct efi_device_path_uri *)
> +                                               lo.file_path,
> +                                       lo.label, handle);
> +                       else
> +                               ret = EFI_LOAD_ERROR;
>                 } else {
>                         file_path = expand_media_path(lo.file_path);
>                         ret = EFI_CALL(efi_load_image(true, efi_root, file_path,
> --
> 2.34.1
>


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