[PATCH v8 4/4] Load option with short device path for boot vars

[Raymond Mao]

The boot variables automatically generated for removable medias
should be with short form of device path without device nodes.
This is a requirement for the case that a removable media is
plugged into a different port but is still able to work with the
existing boot variables.

Signed-off-by: Raymond Mao <raymond.mao at linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
---
Changes in v2
- Ignore EFI_NOT_FOUND returned from
  efi_bootmgr_update_media_device_boot_option which means no boot
  options scanned.
Changes in v3
- Split the patch into moving and renaming functions and
  individual patches for each changed functionality
Changes in v4
- Revert v2 change of introducing a bool parameter when updating
  the boot option. Use short-form of device path by default
Changes in v5
- Add warning log when a short-form device path doesn't exist
Changes in v6
- Revert v5 change and use original device path if short-form does
  not exist

 lib/efi_loader/efi_bootmgr.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
index 28e800499c..398b0f89e2 100644
--- a/lib/efi_loader/efi_bootmgr.c
+++ b/lib/efi_loader/efi_bootmgr.c
@@ -371,6 +371,7 @@ static efi_status_t efi_bootmgr_enumerate_boot_option(struct eficonfig_media_boo
 		struct efi_load_option lo;
 		char buf[BOOTMENU_DEVICE_NAME_MAX];
 		struct efi_device_path *device_path;
+		struct efi_device_path *short_dp;
 
 		ret = efi_search_protocol(volume_handles[i], &efi_guid_device_path, &handler);
 		if (ret != EFI_SUCCESS)
@@ -387,6 +388,11 @@ static efi_status_t efi_bootmgr_enumerate_boot_option(struct eficonfig_media_boo
 		p = dev_name;
 		utf8_utf16_strncpy(&p, buf, strlen(buf));
 
+		/* prefer to short form device path */
+		short_dp = efi_dp_shorten(device_path);
+		if (short_dp)
+			device_path = short_dp;
+
 		lo.label = dev_name;
 		lo.attributes = LOAD_OPTION_ACTIVE;
 		lo.file_path = device_path;
-- 
2.25.1