[efi] Move abstract device path and handle functions to efi_utils.c

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 102 insertions, 0 deletions

diff --git a/src/interface/efi/efi_utils.c b/src/interface/efi/efi_utils.c
new file mode 100644
index 00000000..9a3ec159
--- /dev/null
+++ b/src/interface/efi/efi_utils.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2011 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <string.h>
+#include <errno.h>
+#include <ipxe/efi/efi.h>
+#include <ipxe/efi/efi_utils.h>
+
+/** @file
+ *
+ * EFI utilities
+ *
+ */
+
+/**
+ * Find end of device path
+ *
+ * @v path		Path to device
+ * @ret path_end	End of device path
+ */
+EFI_DEVICE_PATH_PROTOCOL * efi_devpath_end ( EFI_DEVICE_PATH_PROTOCOL *path ) {
+
+	while ( path->Type != END_DEVICE_PATH_TYPE ) {
+		path = ( ( ( void * ) path ) +
+			 /* There's this amazing new-fangled thing known as
+			  * a UINT16, but who wants to use one of those? */
+			 ( ( path->Length[1] << 8 ) | path->Length[0] ) );
+	}
+
+	return path;
+}
+
+/**
+ * Add EFI device as child of another EFI device
+ *
+ * @v parent		EFI parent device handle
+ * @v child		EFI child device handle
+ * @ret rc		Return status code
+ */
+int efi_child_add ( EFI_HANDLE parent, EFI_HANDLE child ) {
+	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+	void *devpath;
+	EFI_STATUS efirc;
+	int rc;
+
+	/* Re-open the device path protocol */
+	if ( ( efirc = bs->OpenProtocol ( parent,
+					  &efi_device_path_protocol_guid,
+					  &devpath,
+					  efi_image_handle, child,
+					  EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
+					  ) ) != 0 ) {
+		rc = -EEFI ( efirc );
+		DBGC ( parent, "EFIDEV %p %s could not add child",
+		       parent, efi_handle_name ( parent ) );
+		DBGC ( parent, " %p %s: %s\n", child,
+		       efi_handle_name ( child ), strerror ( rc ) );
+		DBGC_EFI_OPENERS ( parent, parent,
+				   &efi_device_path_protocol_guid );
+		return rc;
+	}
+
+	DBGC2 ( parent, "EFIDEV %p %s added child",
+		parent, efi_handle_name ( parent ) );
+	DBGC2 ( parent, " %p %s\n", child, efi_handle_name ( child ) );
+	return 0;
+}
+
+/**
+ * Remove EFI device as child of another EFI device
+ *
+ * @v parent		EFI parent device handle
+ * @v child		EFI child device handle
+ */
+void efi_child_del ( EFI_HANDLE parent, EFI_HANDLE child ) {
+	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+
+	bs->CloseProtocol ( parent, &efi_device_path_protocol_guid,
+			    efi_image_handle, child );
+	DBGC2 ( parent, "EFIDEV %p %s removed child",
+		parent, efi_handle_name ( parent ) );
+	DBGC2 ( parent, " %p %s\n",
+		child, efi_handle_name ( child ) );
+}