diff options
Diffstat (limited to 'src/interface/efi')
| -rw-r--r-- | src/interface/efi/efi_utils.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/src/interface/efi/efi_utils.c b/src/interface/efi/efi_utils.c index 9a3ec1598..b4f073304 100644 --- a/src/interface/efi/efi_utils.c +++ b/src/interface/efi/efi_utils.c @@ -49,6 +49,58 @@ EFI_DEVICE_PATH_PROTOCOL * efi_devpath_end ( EFI_DEVICE_PATH_PROTOCOL *path ) { } /** + * Locate parent device supporting a given protocol + * + * @v device EFI device handle + * @v protocol Protocol GUID + * @v parent Parent EFI device handle to fill in + * @ret rc Return status code + */ +int efi_locate_device ( EFI_HANDLE device, EFI_GUID *protocol, + EFI_HANDLE *parent ) { + EFI_BOOT_SERVICES *bs = efi_systab->BootServices; + union { + EFI_DEVICE_PATH_PROTOCOL *path; + void *interface; + } path; + EFI_DEVICE_PATH_PROTOCOL *devpath; + EFI_STATUS efirc; + int rc; + + /* Get device path */ + if ( ( efirc = bs->OpenProtocol ( device, + &efi_device_path_protocol_guid, + &path.interface, + efi_image_handle, device, + EFI_OPEN_PROTOCOL_GET_PROTOCOL ))!=0){ + rc = -EEFI ( efirc ); + DBGC ( device, "EFIDEV %p %s cannot open device path: %s\n", + device, efi_handle_name ( device ), strerror ( rc ) ); + goto err_open_device_path; + } + devpath = path.path; + + /* Check for presence of specified protocol */ + if ( ( efirc = bs->LocateDevicePath ( protocol, &devpath, + parent ) ) != 0 ) { + rc = -EEFI ( efirc ); + DBGC ( device, "EFIDEV %p %s has no parent supporting %s: %s\n", + device, efi_handle_name ( device ), + efi_guid_ntoa ( protocol ), strerror ( rc ) ); + goto err_locate_protocol; + } + + /* Success */ + rc = 0; + + err_locate_protocol: + bs->CloseProtocol ( device, &efi_device_path_protocol_guid, + efi_image_handle, device ); + err_open_device_path: + return rc; +} + +/** * Add EFI device as child of another EFI device * * @v parent EFI parent device handle |