efi_loader: add efi_dp_from_name()

Factor out efi_set_bootdev() and extract efi_dp_from_name().
This function will be used to set a boot device in efishell command.
Signed-off-by: NAKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

cmd/bootefi.c

@@ -608,45 +608,19 @@ U_BOOT_CMD(
 
 void efi_set_bootdev(const char *dev, const char *devnr, const char *path)
 {
-	char filename[32] = { 0 }; /* dp->str is u16[32] long */
-	char *s;
+	struct efi_device_path *device, *image;
+	efi_status_t ret;
 
 	/* efi_set_bootdev is typically called repeatedly, recover memory */
 	efi_free_pool(bootefi_device_path);
 	efi_free_pool(bootefi_image_path);
-	/* If blk_get_device_part_str fails, avoid duplicate free. */
-	bootefi_device_path = NULL;
-	bootefi_image_path = NULL;
-
-	if (strcmp(dev, "Net")) {
-		struct blk_desc *desc;
-		disk_partition_t fs_partition;
-		int part;
-
-		part = blk_get_device_part_str(dev, devnr, &desc, &fs_partition,
-					       1);
-		if (part < 0)
-			return;
-
-		bootefi_device_path = efi_dp_from_part(desc, part);
-	} else {
-#ifdef CONFIG_NET
-		bootefi_device_path = efi_dp_from_eth();
-#endif
-	}
-
-	if (!path)
-		return;
 
-	if (strcmp(dev, "Net")) {
-		/* Add leading / to fs paths, because they're absolute */
-		snprintf(filename, sizeof(filename), "/%s", path);
+	ret = efi_dp_from_name(dev, devnr, path, &device, &image);
+	if (ret == EFI_SUCCESS) {
+		bootefi_device_path = device;
+		bootefi_image_path = image;
 	} else {
-		snprintf(filename, sizeof(filename), "%s", path);
+		bootefi_device_path = NULL;
+		bootefi_image_path = NULL;
 	}
-	/* DOS style file path: */
-	s = filename;
-	while ((s = strchr(s, '/')))
-		*s++ = '\\';
-	bootefi_image_path = efi_dp_from_file(NULL, 0, filename);
 }

include/efi_loader.h

@@ -432,6 +432,10 @@ const struct efi_device_path *efi_dp_last_node(
 efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
 				    struct efi_device_path **device_path,
 				    struct efi_device_path **file_path);
+efi_status_t efi_dp_from_name(const char *dev, const char *devnr,
+			      const char *path,
+			      struct efi_device_path **device,
+			      struct efi_device_path **file);
 
 #define EFI_DP_TYPE(_dp, _type, _subtype) \
 	(((_dp)->type == DEVICE_PATH_TYPE_##_type) && \

lib/efi_loader/efi_device_path.c

@@ -941,3 +941,50 @@ efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
 	*file_path = fp;
 	return EFI_SUCCESS;
 }
+
+efi_status_t efi_dp_from_name(const char *dev, const char *devnr,
+			      const char *path,
+			      struct efi_device_path **device,
+			      struct efi_device_path **file)
+{
+	int is_net;
+	struct blk_desc *desc = NULL;
+	disk_partition_t fs_partition;
+	int part = 0;
+	char filename[32] = { 0 }; /* dp->str is u16[32] long */
+	char *s;
+
+	if (!device || (path && !file))
+		return EFI_INVALID_PARAMETER;
+
+	is_net = !strcmp(dev, "Net");
+	if (!is_net) {
+		part = blk_get_device_part_str(dev, devnr, &desc, &fs_partition,
+					       1);
+		if (part < 0)
+			return EFI_INVALID_PARAMETER;
+
+		*device = efi_dp_from_part(desc, part);
+	} else {
+#ifdef CONFIG_NET
+		*device = efi_dp_from_eth();
+#endif
+	}
+
+	if (!path)
+		return EFI_SUCCESS;
+
+	if (!is_net) {
+		/* Add leading / to fs paths, because they're absolute */
+		snprintf(filename, sizeof(filename), "/%s", path);
+	} else {
+		snprintf(filename, sizeof(filename), "%s", path);
+	}
+	/* DOS style file path: */
+	s = filename;
+	while ((s = strchr(s, '/')))
+		*s++ = '\\';
+	*file = efi_dp_from_file(NULL, 0, filename);
+
+	return EFI_SUCCESS;
+}