This is xnu-8019. See this file in:
/*
 * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#include <IOKit/IODeviceMemory.h>
#include <IOKit/IOSubMemoryDescriptor.h>

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

IODeviceMemory *
IODeviceMemory::withRange(
	IOPhysicalAddress       start,
	IOPhysicalLength        length )
{
	return (IODeviceMemory *) IOMemoryDescriptor::withAddressRange(
		start, length, kIODirectionNone | kIOMemoryMapperNone, NULL );
}


IODeviceMemory *
IODeviceMemory::withSubRange(
	IODeviceMemory *        of,
	IOPhysicalAddress       offset,
	IOPhysicalLength        length )
{
	return (IODeviceMemory *) IOSubMemoryDescriptor::withSubRange(
		of, offset, length, kIODirectionNone );
}


OSArray *
IODeviceMemory::arrayFromList(
	InitElement             list[],
	IOItemCount             count )
{
	OSArray *           array;
	IODeviceMemory *    range;
	IOItemCount         i;

	array = OSArray::withCapacity( count );
	if (NULL == array) {
		return NULL;
	}

	for (i = 0; i < count; i++) {
		range = IODeviceMemory::withRange( list[i].start, list[i].length );
		if (range) {
			range->setTag( list[i].tag );
			array->setObject( range);
			range->release();
		} else {
			array->release();
			array = NULL;
			break;
		}
	}

	return array;
}