efi_loader: reformat efi_disk_add_dev()

Make it clearer why InstallMultipleProtocolInterfaces is invoked with two
NULLs:

* rename guid to esp_guid
* put protocol GUIDs and the related interfaces on same lines
* add comment

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

diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
index a209505..cef4e45 100644 (file)
--- a/lib/efi_loader/efi_disk.c
+++ b/lib/efi_loader/efi_disk.c
@@ -395,7 +395,7 @@ static efi_status_t efi_disk_add_dev(
 {
        struct efi_disk_obj *diskobj;
        struct efi_object *handle;
-       const efi_guid_t *guid = NULL;
+       const efi_guid_t *esp_guid = NULL;
        efi_status_t ret;
 
        /* Don't add empty devices */
@@ -439,7 +439,7 @@ static efi_status_t efi_disk_add_dev(
                efi_free_pool(node);
                diskobj->media.last_block = part_info->size - 1;
                if (part_info->bootable & PART_EFI_SYSTEM_PARTITION)
-                       guid = &efi_system_partition_guid;
+                       esp_guid = &efi_system_partition_guid;
        } else {
                diskobj->dp = efi_dp_from_part(desc, part);
                diskobj->media.last_block = desc->lba - 1;
@@ -454,12 +454,16 @@ static efi_status_t efi_disk_add_dev(
         * in this case.
         */
        handle = &diskobj->header;
-       ret = efi_install_multiple_protocol_interfaces(&handle,
-                                                      &efi_guid_device_path,
-                                                      diskobj->dp,
-                                                      &efi_block_io_guid,
-                                                      &diskobj->ops, guid,
-                                                      NULL, NULL);
+       ret = efi_install_multiple_protocol_interfaces(
+                                       &handle,
+                                       &efi_guid_device_path, diskobj->dp,
+                                       &efi_block_io_guid, &diskobj->ops,
+                                       /*
+                                        * esp_guid must be last entry as it
+                                        * can be NULL. Its interface is NULL.
+                                        */
+                                       esp_guid, NULL,
+                                       NULL);
        if (ret != EFI_SUCCESS)
                goto error;