This is xnu-8019. See this file in:
/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
 * Reserved.  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 1.0 (the 'License').  You may not use this file
 * except in compliance with the License.  Please obtain a copy of the
 * License at http://www.apple.com/publicsource 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 OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License."
 *
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Mach Operating System
 * Copyright (c) 1990 Carnegie-Mellon University
 * Copyright (c) 1989 Carnegie-Mellon University
 * Copyright (c) 1988 Carnegie-Mellon University
 * Copyright (c) 1987 Carnegie-Mellon University
 * All rights reserved.  The CMU software License Agreement specifies
 * the terms and conditions for use and redistribution.
 */

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <stdio.h>
#include <unistd.h>     /* for unlink */
#include "parser.h"
#include "config.h"

/*
 * build the ioconf.c file
 */
void    pseudo_inits(FILE *fp);

void
mkioconf(void)
{
	FILE *fp;

	unlink(path("ioconf.c"));
	fp = fopen(path("ioconf.c"), "w");
	if (fp == 0) {
		perror(path("ioconf.c"));
		exit(1);
	}
	fprintf(fp, "#include <dev/busvar.h>\n");
	fprintf(fp, "\n");
	pseudo_inits(fp);
	(void) fclose(fp);
}

void
pseudo_inits(FILE *fp)
{
	struct device *dp;
	int count;

	fprintf(fp, "\n");
	for (dp = dtab; dp != 0; dp = dp->d_next) {
		if (dp->d_type != PSEUDO_DEVICE || dp->d_init == 0) {
			continue;
		}
		fprintf(fp, "extern int %s(int);\n", dp->d_init);
	}
	fprintf(fp, "\nstruct pseudo_init pseudo_inits[] = {\n");
	for (dp = dtab; dp != 0; dp = dp->d_next) {
		if (dp->d_type != PSEUDO_DEVICE || dp->d_init == 0) {
			continue;
		}
		count = dp->d_slave;
		if (count <= 0) {
			count = 1;
		}
		fprintf(fp, "\t{%d,\t%s},\n", count, dp->d_init);
	}
	fprintf(fp, "\t{0,\t0},\n};\n");
}