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/*
* Copyright (C) 2020 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.
*/
#include <ipxe/efi/efi.h>
#include <ipxe/efi/efi_path.h>
/** @file
*
* EFI device paths
*
*/
/**
* Find end of device path
*
* @v path Path to device
* @ret path_end End of device path
*/
EFI_DEVICE_PATH_PROTOCOL * efi_path_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;
}
/**
* Find length of device path (excluding terminator)
*
* @v path Path to device
* @ret path_len Length of device path
*/
size_t efi_path_len ( EFI_DEVICE_PATH_PROTOCOL *path ) {
EFI_DEVICE_PATH_PROTOCOL *end = efi_path_end ( path );
return ( ( ( void * ) end ) - ( ( void * ) path ) );
}
/**
* Describe object as an EFI device path
*
* @v intf Interface
* @ret path EFI device path, or NULL
*
* The caller is responsible for eventually calling free() on the
* allocated device path.
*/
EFI_DEVICE_PATH_PROTOCOL * efi_describe ( struct interface *intf ) {
struct interface *dest;
efi_describe_TYPE ( void * ) *op =
intf_get_dest_op ( intf, efi_describe, &dest );
void *object = intf_object ( dest );
EFI_DEVICE_PATH_PROTOCOL *path;
if ( op ) {
path = op ( object );
} else {
path = NULL;
}
intf_put ( dest );
return path;
}
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