diff --git a/usr.sbin/installboot/arch/i386.c b/usr.sbin/installboot/arch/i386.c
new file mode 100644
index 000000000000..9ef87020d5af
--- /dev/null
+++ b/usr.sbin/installboot/arch/i386.c
@@ -0,0 +1,153 @@
+/* $NetBSD: i386.c,v 1.1 2003/04/09 22:14:27 dsl Exp $ */
+
+/*-
+ * Copyright (c) 2003 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by David Laight.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *        This product includes software developed by the NetBSD
+ *        Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__RCSID("$NetBSD: i386.c,v 1.1 2003/04/09 22:14:27 dsl Exp $");
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <sys/param.h>
+
+#include <assert.h>
+#include <err.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "installboot.h"
+
+/* Magic number also known by sys/arch/i386/stand/bootxx/Makefile.bootxx */
+#define BOOT_MAGIC_1	('x' << 24 | 0x86b << 12 | 'm' << 4 | 1)
+
+int
+i386_setboot(ib_params *params)
+{
+	int		retval;
+	char		*bootstrapbuf;
+	uint		bootstrapsize;
+	ssize_t		rv;
+	uint32_t	magic;
+
+	assert(params != NULL);
+	assert(params->fsfd != -1);
+	assert(params->filesystem != NULL);
+	assert(params->s1fd != -1);
+	assert(params->stage1 != NULL);
+
+	retval = 0;
+	bootstrapbuf = NULL;
+
+	if (params->flags & IB_STAGE1START) {
+		warnx("`-b bno' is not supported for %s",
+		    params->machine->name);
+		goto done;
+	}
+	if (params->flags & IB_STAGE2START) {
+		warnx("`-B bno' is not supported for %s",
+		    params->machine->name);
+		goto done;
+	}
+
+	/*
+	 * Allocate a buffer, with space to round up the input file
+	 * to the next block size boundary, and with space for the boot
+	 * block.
+	 */
+	bootstrapsize = roundup(params->s1stat.st_size, 512);
+
+	bootstrapbuf = malloc(bootstrapsize);
+	if (bootstrapbuf == NULL) {
+		warn("Allocating %u bytes",  bootstrapsize);
+		goto done;
+	}
+	memset(bootstrapbuf, 0, bootstrapsize);
+
+	/* read the file into the buffer */
+	rv = pread(params->s1fd, bootstrapbuf, params->s1stat.st_size, 0);
+	if (rv == -1) {
+		warn("Reading `%s'", params->stage1);
+		return 0;
+	} else if (rv != params->s1stat.st_size) {
+		warnx("Reading `%s': short read", params->stage1);
+		return 0;
+	}
+
+	magic = *(uint32_t *)(bootstrapbuf + 512 * 2 + 4);
+	if (magic != BOOT_MAGIC_1) {
+		warnx("Invalid magic in stage1 boostrap %x != %x",
+			magic, BOOT_MAGIC_1);
+		goto done;
+	}
+
+	if (params->flags & IB_NOWRITE) {
+		retval = 1;
+		goto done;
+	}
+
+	/* Write pbr code to sector zero */
+	rv = pwrite(params->fsfd, bootstrapbuf, 512, 0);
+	if (rv == -1) {
+		warn("Writing `%s'", params->filesystem);
+		goto done;
+	} else if (rv != 512) {
+		warnx("Writing `%s': short write", params->filesystem);
+		goto done;
+	}
+
+	/* Skip disklabel and write bootxx to sectors 2 + */
+	rv = pwrite(params->fsfd, bootstrapbuf + 512 * 2,
+		    bootstrapsize - 512 * 2, 512 * 2);
+	if (rv == -1) {
+		warn("Writing `%s'", params->filesystem);
+		goto done;
+	} else if (rv != bootstrapsize - 512 * 2) {
+		warnx("Writing `%s': short write", params->filesystem);
+		goto done;
+	}
+
+	retval = 1;
+
+ done:
+	if (bootstrapbuf)
+		free(bootstrapbuf);
+	return retval;
+}