cmd: eficonfig: add support for setting fdt

We already support creating a load option where the device-path
field contains the concatenation of the binary device-path and
optionally the device path of the initrd which we expose via the
EFI_LOAD_FILE2_PROTOCOL.

Allow to append another device-path pointing to the device-tree
identified by the device-tree GUID.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

cmd/eficonfig.c

@@ -61,6 +61,7 @@ struct eficonfig_filepath_info {
 struct eficonfig_boot_option {
 	struct eficonfig_select_file_info file_info;
 	struct eficonfig_select_file_info initrd_info;
+	struct eficonfig_select_file_info fdt_info;
 	unsigned int boot_index;
 	u16 *description;
 	u16 *optional_data;
@@ -1307,6 +1308,10 @@ static efi_status_t eficonfig_show_boot_option(struct eficonfig_boot_option *bo,
 	if (ret != EFI_SUCCESS)
 		goto out;
 
+	ret = prepare_file_selection_entry(efi_menu, "Fdt File: ", &bo->fdt_info);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
 	ret = create_boot_option_entry(efi_menu, "Optional Data: ", bo->optional_data,
 				       eficonfig_boot_add_optional_data, bo);
 	if (ret != EFI_SUCCESS)
@@ -1387,27 +1392,44 @@ static efi_status_t eficonfig_edit_boot_option(u16 *varname, struct eficonfig_bo
 	efi_status_t ret;
 	char *tmp = NULL, *p;
 	struct efi_load_option lo = {0};
-	efi_uintn_t final_dp_size;
+	efi_uintn_t dp_size;
 	struct efi_device_path *dp = NULL;
 	efi_uintn_t size = load_option_size;
-	struct efi_device_path *final_dp = NULL;
 	struct efi_device_path *device_dp = NULL;
 	struct efi_device_path *initrd_dp = NULL;
+	struct efi_device_path *fdt_dp = NULL;
 	struct efi_device_path *initrd_device_dp = NULL;
+	struct efi_device_path *fdt_device_dp = NULL;
 
-	const struct efi_initrd_dp id_dp = {
+	const struct efi_initrd_dp initrd_prefix = {
 		.vendor = {
 			{
 			DEVICE_PATH_TYPE_MEDIA_DEVICE,
 			DEVICE_PATH_SUB_TYPE_VENDOR_PATH,
-			sizeof(id_dp.vendor),
+			sizeof(initrd_prefix.vendor),
 			},
 			EFI_INITRD_MEDIA_GUID,
 		},
 		.end = {
 			DEVICE_PATH_TYPE_END,
 			DEVICE_PATH_SUB_TYPE_END,
-			sizeof(id_dp.end),
+			sizeof(initrd_prefix.end),
+		}
+	};
+
+	const struct efi_initrd_dp fdt_prefix = {
+		.vendor = {
+			{
+			DEVICE_PATH_TYPE_MEDIA_DEVICE,
+			DEVICE_PATH_SUB_TYPE_VENDOR_PATH,
+			sizeof(fdt_prefix.vendor),
+			},
+			EFI_FDT_GUID,
+		},
+		.end = {
+			DEVICE_PATH_TYPE_END,
+			DEVICE_PATH_SUB_TYPE_END,
+			sizeof(initrd_prefix.end),
 		}
 	};
 
@@ -1423,6 +1445,12 @@ static efi_status_t eficonfig_edit_boot_option(u16 *varname, struct eficonfig_bo
 		goto out;
 	}
 
+	bo->fdt_info.current_path = calloc(1, EFICONFIG_FILE_PATH_BUF_SIZE);
+	if (!bo->fdt_info.current_path) {
+		ret =  EFI_OUT_OF_RESOURCES;
+		goto out;
+	}
+
 	bo->description = calloc(1, EFICONFIG_DESCRIPTION_MAX * sizeof(u16));
 	if (!bo->description) {
 		ret =  EFI_OUT_OF_RESOURCES;
@@ -1455,13 +1483,20 @@ static efi_status_t eficonfig_edit_boot_option(u16 *varname, struct eficonfig_bo
 		if (lo.file_path)
 			fill_file_info(lo.file_path, &bo->file_info, device_dp);
 
-		/* Initrd file path(optional) is placed at second instance. */
+		/* Initrd file path (optional) is placed at second instance. */
 		initrd_dp = efi_dp_from_lo(&lo, &efi_lf2_initrd_guid);
 		if (initrd_dp) {
 			fill_file_info(initrd_dp, &bo->initrd_info, initrd_device_dp);
 			efi_free_pool(initrd_dp);
 		}
 
+		/* Fdt file path (optional) is placed as third instance. */
+		fdt_dp = efi_dp_from_lo(&lo, &efi_guid_fdt);
+		if (fdt_dp) {
+			fill_file_info(fdt_dp, &bo->fdt_info, fdt_device_dp);
+			efi_free_pool(fdt_dp);
+		}
+
 		if (size > 0)
 			memcpy(bo->optional_data, lo.optional_data, size);
 	}
@@ -1483,26 +1518,31 @@ static efi_status_t eficonfig_edit_boot_option(u16 *varname, struct eficonfig_bo
 			ret = EFI_OUT_OF_RESOURCES;
 			goto out;
 		}
-		initrd_dp = efi_dp_concat((const struct efi_device_path *)&id_dp,
+		initrd_dp = efi_dp_concat((const struct efi_device_path *)&initrd_prefix,
 					  dp, 0);
 		efi_free_pool(dp);
 	}
 
+	if (bo->fdt_info.dp_volume) {
+		dp = eficonfig_create_device_path(bo->fdt_info.dp_volume,
+						  bo->fdt_info.current_path);
+		if (!dp) {
+			ret = EFI_OUT_OF_RESOURCES;
+			goto out;
+		}
+		fdt_dp = efi_dp_concat((const struct efi_device_path *)&fdt_prefix,
+				       dp, 0);
+		efi_free_pool(dp);
+	}
+
 	dp = eficonfig_create_device_path(bo->file_info.dp_volume, bo->file_info.current_path);
 	if (!dp) {
 		ret = EFI_OUT_OF_RESOURCES;
 		goto out;
 	}
-	final_dp_size = efi_dp_size(dp) + sizeof(END);
-	if (initrd_dp) {
-		final_dp = efi_dp_concat(dp, initrd_dp, 1);
-		final_dp_size += efi_dp_size(initrd_dp) + sizeof(END);
-	} else {
-		final_dp = efi_dp_dup(dp);
-	}
-	efi_free_pool(dp);
 
-	if (!final_dp)
+	ret = efi_load_option_dp_join(&dp, &dp_size, initrd_dp, fdt_dp);
+	if (ret != EFI_SUCCESS)
 		goto out;
 
 	if (utf16_utf8_strlen(bo->optional_data)) {
@@ -1514,17 +1554,20 @@ static efi_status_t eficonfig_edit_boot_option(u16 *varname, struct eficonfig_bo
 		utf16_utf8_strncpy(&p, bo->optional_data, u16_strlen(bo->optional_data));
 	}
 
-	ret = eficonfig_set_boot_option(varname, final_dp, final_dp_size, bo->description, tmp);
+	ret = eficonfig_set_boot_option(varname, dp, dp_size, bo->description, tmp);
 out:
 	free(tmp);
 	free(bo->optional_data);
 	free(bo->description);
 	free(bo->file_info.current_path);
 	free(bo->initrd_info.current_path);
+	free(bo->fdt_info.current_path);
 	efi_free_pool(device_dp);
 	efi_free_pool(initrd_device_dp);
 	efi_free_pool(initrd_dp);
-	efi_free_pool(final_dp);
+	efi_free_pool(fdt_device_dp);
+	efi_free_pool(fdt_dp);
+	efi_free_pool(dp);
 
 	return ret;
 }

include/efi_loader.h

@@ -1185,4 +1185,18 @@ efi_status_t efi_disk_get_device_name(const efi_handle_t handle, char *buf, int
  */
 void efi_add_known_memory(void);
 
+/**
+ * efi_load_option_dp_join() - join device-paths for load option
+ *
+ * @dp:		in: binary device-path, out: joined device-path
+ * @dp_size:	size of joined device-path
+ * @initrd_dp:	initrd device-path or NULL
+ * @fdt_dp:	device-tree device-path or NULL
+ * Return:	status_code
+ */
+efi_status_t efi_load_option_dp_join(struct efi_device_path **dp,
+				     size_t *dp_size,
+				     struct efi_device_path *initrd_dp,
+				     struct efi_device_path *fdt_dp);
+
 #endif /* _EFI_LOADER_H */

lib/efi_loader/efi_helper.c

@@ -99,6 +99,50 @@ err:
 	return NULL;
 }
 
+/**
+ * efi_load_option_dp_join() - join device-paths for load option
+ *
+ * @dp:		in: binary device-path, out: joined device-path
+ * @dp_size:	size of joined device-path
+ * @initrd_dp:	initrd device-path or NULL
+ * @fdt_dp:	device-tree device-path or NULL
+ * Return:	status_code
+ */
+efi_status_t efi_load_option_dp_join(struct efi_device_path **dp,
+				     size_t *dp_size,
+				     struct efi_device_path *initrd_dp,
+				     struct efi_device_path *fdt_dp)
+{
+	if (!dp)
+		return EFI_INVALID_PARAMETER;
+
+	*dp_size = efi_dp_size(*dp);
+
+	if (initrd_dp) {
+		struct efi_device_path *tmp_dp = *dp;
+
+		*dp = efi_dp_concat(tmp_dp, initrd_dp, *dp_size);
+		efi_free_pool(tmp_dp);
+		if (!*dp)
+			return EFI_OUT_OF_RESOURCES;
+		*dp_size += efi_dp_size(initrd_dp) + sizeof(END);
+	}
+
+	if (fdt_dp) {
+		struct efi_device_path *tmp_dp = *dp;
+
+		*dp = efi_dp_concat(tmp_dp, fdt_dp, *dp_size);
+		efi_free_pool(tmp_dp);
+		if (!dp)
+			return EFI_OUT_OF_RESOURCES;
+		*dp_size += efi_dp_size(fdt_dp) + sizeof(END);
+	}
+
+	*dp_size += sizeof(END);
+
+	return EFI_SUCCESS;
+}
+
 const struct guid_to_hash_map {
 	efi_guid_t guid;
 	const char algo[32];