diff --git a/usr.sbin/installboot/ffs.c b/usr.sbin/installboot/ffs.c
index a33dfe720df3..080a05c85520 100644
--- a/usr.sbin/installboot/ffs.c
+++ b/usr.sbin/installboot/ffs.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: ffs.c,v 1.1 2002/04/19 07:08:51 lukem Exp $	*/
+/*	$NetBSD: ffs.c,v 1.2 2002/04/30 14:21:17 lukem Exp $	*/
 
 /*-
  * Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -38,7 +38,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(__lint)
-__RCSID("$NetBSD: ffs.c,v 1.1 2002/04/19 07:08:51 lukem Exp $");
+__RCSID("$NetBSD: ffs.c,v 1.2 2002/04/30 14:21:17 lukem Exp $");
 #endif	/* !__lint */
 
 #include <sys/param.h>
@@ -70,6 +70,8 @@ ffs_read_disk_block(ib_params *params, uint32_t blkno, int size, char *blk)
 {
 	int	rv;
 
+	assert(params != NULL);
+	assert(blk != NULL);
 	assert(params->filesystem != NULL);
 	assert(params->fsfd != -1);
 	assert(blkno > 0);
@@ -114,6 +116,10 @@ ffs_find_disk_blocks(ib_params *params, uint32_t ino,
 		char		diskbuf[MAXBSIZE];
 	} level[LEVELS];
 
+	assert(params != NULL);
+	assert(callback != NULL);
+	assert(state != NULL);
+
 	/* Read the superblock. */
 	if (! ffs_read_disk_block(params, SBLOCK, SBSIZE, sbbuf))
 		return (0);
@@ -244,6 +250,9 @@ ffs_findstage2_ino(ib_params *params, void *_ino,
 	struct direct	*de, *ede;
 	uint32_t	ino;
 
+	assert(params != NULL);
+	assert(_ino != NULL);
+
 	/* Skip directory holes. */
 	if (blk == 0)
 		return (1);
@@ -284,6 +293,9 @@ ffs_findstage2_blocks(ib_params *params, void *_state,
 {
 	struct findblks_state *state = _state;
 
+	assert(params != NULL);
+	assert(_state != NULL);
+
 	if (state->nblk == state->maxblk) {
 		warnx("Secondary bootstrap `%s' has too many blocks " \
 		    "(max %d)\n", params->stage2, state->maxblk);
@@ -303,6 +315,9 @@ ffs_match(ib_params *params)
 	char		sbbuf[SBSIZE];
 	struct fs	*fs;
 
+	assert(params != NULL);
+	assert(params->stage2 != NULL);
+
 	/* Read and check the superblock. */
 	if (! ffs_read_disk_block(params, SBLOCK, SBSIZE, sbbuf))
 		return (0);
@@ -321,7 +336,10 @@ ffs_findstage2(ib_params *params, uint32_t *maxblk, ib_block *blocks)
 	uint32_t		ino;
 	struct findblks_state	state;
 
-	assert (params->stage2 != NULL);
+	assert(params != NULL);
+	assert(params->stage2 != NULL);
+	assert(maxblk != NULL);
+	assert(blocks != NULL);
 
 	/* The secondary bootstrap must be clearly in /. */
 	if (params->stage2[0] == '/')
diff --git a/usr.sbin/installboot/installboot.c b/usr.sbin/installboot/installboot.c
index 9fcff9dd08f1..76817377f265 100644
--- a/usr.sbin/installboot/installboot.c
+++ b/usr.sbin/installboot/installboot.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: installboot.c,v 1.6 2002/04/19 07:08:52 lukem Exp $	*/
+/*	$NetBSD: installboot.c,v 1.7 2002/04/30 14:21:17 lukem Exp $	*/
 
 /*-
  * Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -38,7 +38,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(__lint)
-__RCSID("$NetBSD: installboot.c,v 1.6 2002/04/19 07:08:52 lukem Exp $");
+__RCSID("$NetBSD: installboot.c,v 1.7 2002/04/30 14:21:17 lukem Exp $");
 #endif	/* !__lint */
 
 #include <sys/utsname.h>
@@ -171,7 +171,7 @@ main(int argc, char *argv[])
 			! params->fstype->match(params))
 			params->fstype++;
 		if (params->fstype->name == NULL)
-			err(1, "File system `%s' is of an unknown type",
+			errx(1, "File system `%s' is of an unknown type",
 			    params->filesystem);
 	}
 
@@ -251,6 +251,9 @@ int
 no_parseopt(ib_params *params, const char *option)
 {
 
+	assert(params != NULL);
+	assert(option != NULL);
+
 		/* all options are unsupported */
 	warnx("Unsupported -o option `%s'", option);
 	return (0);
@@ -260,6 +263,8 @@ int
 no_setboot(ib_params *params)
 {
 
+	assert(params != NULL);
+
 		/* bootstrap installation is not supported */
 	warnx("%s: bootstrap installation is not supported",
 	    params->machine->name);
@@ -270,6 +275,8 @@ int
 no_clearboot(ib_params *params)
 {
 
+	assert(params != NULL);
+
 		/* bootstrap removal is not supported */
 	warnx("%s: bootstrap removal is not supported",
 	    params->machine->name);
@@ -284,6 +291,7 @@ getmachine(ib_params *param, const char *mach, const char *provider)
 
 	assert(param != NULL);
 	assert(mach != NULL);
+	assert(provider != NULL);
 
 	for (i = 0; machines[i].name != NULL; i++) {
 		if (strcmp(machines[i].name, mach) == 0) {
@@ -312,6 +320,7 @@ getfstype(ib_params *param, const char *fstype, const char *provider)
 
 	assert(param != NULL);
 	assert(fstype != NULL);
+	assert(provider != NULL);
 
 	for (i = 0; fstypes[i].name != NULL; i++) {
 		if (strcmp(fstypes[i].name, fstype) == 0) {