diff --git a/include/unistd.h b/include/unistd.h
index 5099885..cf48903 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -93,7 +93,7 @@ char    *re_comp();
 void    *sbrk(int incr);
 int     sethostid();
 void    setusershell();
-void    sync();
+void    sync(void);
 unsigned int    ualarm();
 void    usleep();
 int     pause(void);
@@ -155,6 +155,7 @@ int     getpagesize(void);
 int     symlink(const char *target, const char *linkpath);
 int     vhangup(void);
 int     mknod(const char *, mode_t, dev_t);
+int     reboot(int howto);
 
 #ifndef _VA_LIST_
 # ifdef __GNUC__
diff --git a/src/cmd/pstat/pstat.c b/src/cmd/pstat/pstat.c
index b01f0b4..a5aaa8c 100644
--- a/src/cmd/pstat/pstat.c
+++ b/src/cmd/pstat/pstat.c
@@ -20,6 +20,8 @@
 #include <nlist.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
 
 char	*fcore	= "/dev/kmem";
 char	*fmem	= "/dev/mem";
@@ -54,7 +56,18 @@ int	totflg;
 int	allflg;
 int	kflg;
 
-main(argc, argv)
+static void usage(void);
+static void dofile(void);
+static void doinode(void);
+static void doproc(void);
+static void dotty(void);
+static void dousr(void);
+static void doswap(void);
+static void putf(long v, char n);
+static void dottytype(char *name, int type);
+static void ttyprt(struct tty *atp, int line);
+
+int main(argc, argv)
 char **argv;
 {
 	register char *argp;
@@ -147,12 +160,12 @@ char **argv;
 		doswap();
 }
 
-usage()
+void usage()
 {
 	printf("usage: pstat -[aikptfsT] [-u [ubase]] [core]\n");
 }
 
-doinode()
+void doinode()
 {
 	register struct inode *ip;
 	struct inode *xinode;
@@ -207,7 +220,7 @@ doinode()
 			printf("%6d,%3d", major(ip->i_rdev), minor(ip->i_rdev));
 		else
 			printf("%10ld", ip->i_size);
-		printf(" %08x", ip->i_fs);
+		printf(" %p", ip->i_fs);
 		printf("\n");
 	}
 	free(xinode);
@@ -225,9 +238,7 @@ getuint(loc)
 	return (word);
 }
 
-putf(v, n)
-	long	v;
-	char	n;
+void putf(long v, char n)
 {
 	if (v)
 		printf("%c", n);
@@ -235,12 +246,12 @@ putf(v, n)
 		printf(" ");
 }
 
-doproc()
+void doproc()
 {
 	struct proc *xproc;
 	u_int nproc, aproc;
 	register struct proc *pp;
-	register loc, np;
+	register int loc, np;
 
 	nproc = getuint((off_t)nl[SNPROC].n_value);
 	xproc = (struct proc *)calloc(nproc, sizeof (struct proc));
@@ -286,8 +297,8 @@ doproc()
 		printf(" %8x", pp->p_saddr);
 		printf(" %8x", pp->p_daddr);
 		printf(" %6x", pp->p_dsize+pp->p_ssize);
-		printf(" %8x", pp->p_wchan);
-		printf(" %8x", pp->p_link);
+		printf(" %p", pp->p_wchan);
+		printf(" %p", pp->p_link);
 		printf(" %8.1lx", pp->p_sigmask);
 		printf("\n");
 	}
@@ -297,7 +308,7 @@ doproc()
 static int ttyspace = 64;
 static struct tty *tty;
 
-dotty()
+void dotty()
 {
 	if ((tty = (struct tty *)malloc(ttyspace * sizeof(*tty))) == 0) {
 		printf("pstat: out of memory\n");
@@ -306,7 +317,7 @@ dotty()
 	dottytype("cn", SKL);
 }
 
-dottytype(name, type)
+void dottytype(name, type)
 char *name;
 {
 	register struct tty *tp;
@@ -318,7 +329,7 @@ char *name;
 	ttyprt(tty, 0);
 }
 
-ttyprt(atp, line)
+void ttyprt(atp, line)
 struct tty *atp;
 {
 	register struct tty *tp;
@@ -327,7 +338,7 @@ struct tty *atp;
 	tp = atp;
 
 	printf("%4d%4d", tp->t_rawq.c_cc, tp->t_canq.c_cc);
-	printf("%4d %12.1lo %8x %4d %4d ", tp->t_outq.c_cc, tp->t_flags,
+	printf("%4d %12.1lo %p %4d %4d ", tp->t_outq.c_cc, tp->t_flags,
 		tp->t_addr, tp->t_delct, tp->t_col);
 	putf(tp->t_state&TS_TIMEOUT, 'T');
 	putf(tp->t_state&TS_WOPEN, 'W');
@@ -346,24 +357,24 @@ struct tty *atp;
 	printf("%6d\n", tp->t_pgrp);
 }
 
-dousr()
+void dousr()
 {
 	struct user U;
 	long	*ip;
-	register i, j;
+	register int i, j;
 
 	lseek(fm, ubase, 0);
 	read(fm, &U, sizeof(U));
 	printf("procp\t%p\n", U.u_procp);
 	printf("frame\t%p\n", U.u_frame);
 	printf("comm\t%s\n", U.u_comm);
-	printf("arg\t%p %p %p %p %p %p\n", U.u_arg[0], U.u_arg[1],
+	printf("arg\t%08x %08x %08x %08x %08x %08x\n", U.u_arg[0], U.u_arg[1],
 		U.u_arg[2], U.u_arg[3], U.u_arg[4], U.u_arg[5]);
 	printf("qsave\t");
 	for (i = 0; i < sizeof (label_t) / sizeof (int); i++)
-		printf("%p ", U.u_qsave.val[i]);
+		printf("%08x ", U.u_qsave.val[i]);
 	printf("\n");
-	printf("rval\t%p\n", U.u_rval);
+	printf("rval\t%08x\n", U.u_rval);
 	printf("error\t%d\n", U.u_error);
 	printf("uids\t%d,%d,%d,%d,%d\n", U.u_uid, U.u_svuid, U.u_ruid,
 		U.u_svgid, U.u_rgid);
@@ -388,7 +399,7 @@ dousr()
 	printf("signal");
 	for (i = 0; i < NSIG; i++) {
 		if (i%8 == 0) printf("\t");
-		printf("%.1x ", U.u_signal[i]);
+		printf("%p ", U.u_signal[i]);
 		if (i%8 == 7) printf("\n");
 	}
 	if (i%8) printf("\n");
@@ -404,13 +415,13 @@ dousr()
 	printf("oldmask\t%.1lx\n", U.u_oldmask);
 	printf("code\t%08x\n", U.u_code);
 	printf("psflags\t%d\n", U.u_psflags);
-	printf("ss_base\t%.1x ss_size %.1x ss_flags %.1x\n",
+	printf("ss_base\t%p ss_size %.1x ss_flags %.1x\n",
 		U.u_sigstk.ss_base, U.u_sigstk.ss_size, U.u_sigstk.ss_flags);
 	printf("ofile");
 	for	(i = 0; i < NOFILE; i++)
 		{
 		if	(i%8 == 0) printf("\t");
-		printf("%.1x ", U.u_ofile[i]);
+		printf("%p ", U.u_ofile[i]);
 		if	(i%8 == 7) printf("\n");
 		}
 	if	(i%8) printf("\n");
@@ -423,9 +434,9 @@ dousr()
 		}
 	if	(i%8) printf("\n");
 	printf("lastfile\t%d\n", U.u_lastfile);
-	printf("cdir\t%.1x\n", U.u_cdir);
-	printf("rdir\t%.1x\n", U.u_rdir);
-	printf("ttyp\t%.1x\n", U.u_ttyp);
+	printf("cdir\t%p\n", U.u_cdir);
+	printf("rdir\t%p\n", U.u_rdir);
+	printf("ttyp\t%p\n", U.u_ttyp);
 	printf("ttyd\t%d,%d\n", major(U.u_ttyd), minor(U.u_ttyd));
 	printf("cmask\t%.1x\n", U.u_cmask);
 	printf("ru\t");
@@ -441,8 +452,8 @@ dousr()
 	printf("timer\t%ld %ld %ld %ld\n", U.u_timer[0].it_interval,
 		U.u_timer[0].it_value, U.u_timer[1].it_interval,
 		U.u_timer[1].it_value);
-	printf("start\t%08x\n", U.u_start);
-	printf("prof\t%.1x %u %u %u\n", U.u_prof.pr_base, U.u_prof.pr_size,
+	printf("start\t%08lx\n", U.u_start);
+	printf("prof\t%p %u %u %u\n", U.u_prof.pr_base, U.u_prof.pr_size,
 		U.u_prof.pr_off, U.u_prof.pr_scale);
 	printf("rlimit cur\t");
 	for	(i = 0; i < RLIM_NLIMITS; i++)
@@ -467,10 +478,10 @@ dousr()
 		minor(U.u_ncache.nc_dev));
 }
 
-oatoi(s)
+int oatoi(s)
 char *s;
 {
-	register v;
+	int v;
 
 	v = 0;
 	while (*s)
@@ -478,11 +489,11 @@ char *s;
 	return(v);
 }
 
-dofile()
+void dofile()
 {
 	struct file *xfile;
 	register struct file *fp;
-	register nf;
+	register int nf;
 	u_int loc, afile;
 	static char *dtypes[] = { "???", "inode", "socket", "pipe" };
 
@@ -513,7 +524,7 @@ dofile()
 		if (fp->f_type <= DTYPE_PIPE)
 			printf("%-8.8s", dtypes[fp->f_type]);
 		else
-			printf("8d", fp->f_type);
+			printf("%8d", fp->f_type);
 		putf((long)fp->f_flag&FREAD, 'R');
 		putf((long)fp->f_flag&FWRITE, 'W');
 		putf((long)fp->f_flag&FAPPEND, 'A');
@@ -525,7 +536,7 @@ dofile()
 		putf((long)fp->f_flag&FDEFER, 'd');
 		printf("  %3d", fp->f_count);
 		printf("  %3d", fp->f_msgcount);
-		printf("  %08x", fp->f_data);
+		printf("  %p", fp->f_data);
 		if (fp->f_offset < 0)
 			printf("  0x%lx\n", fp->f_offset);
 		else
@@ -534,7 +545,7 @@ dofile()
 	free(xfile);
 }
 
-doswap()
+void doswap()
 {
 	u_int	nswap, used;
 	int	i, num;
diff --git a/src/cmd/reboot/reboot.c b/src/cmd/reboot/reboot.c
index f266ec4..3c5a2f0 100644
--- a/src/cmd/reboot/reboot.c
+++ b/src/cmd/reboot/reboot.c
@@ -13,6 +13,8 @@
 #include <pwd.h>
 #include <sysexits.h>
 #include <unistd.h>
+#include <fcntl.h>
+#include <time.h>
 #include <sys/syslog.h>
 #include <sys/file.h>
 #include <sys/reboot.h>
@@ -20,7 +22,9 @@
 
 #define	OPTS	"lqnhdarsfRD"
 
-main(argc, argv)
+static void markdown(void);
+
+int main(argc, argv)
 	int argc;
 	char **argv;
 {
@@ -30,12 +34,12 @@ main(argc, argv)
 	char *myname;		/* name we were invoked as */
 	char args[20], *ap;	/* collected arguments for syslog */
 	int i;
-	char *rindex();
 
-	if (myname = rindex(argv[0], '/'))
+	if ((myname = rindex(argv[0], '/')))
 		myname++;
 	else
 		myname = argv[0];
+
 	if (strcmp(myname, "halt") == 0)
 		howto = RB_HALT;
 	else if (strcmp(myname, "fasthalt") == 0)
@@ -44,8 +48,8 @@ main(argc, argv)
 		howto = RB_NOFSCK;
 	else if (strcmp(myname, "poweroff") == 0)
 		howto = RB_HALT|RB_POWEROFF;
-    else if (strcmp(myname, "bootloader") == 0)
-        howto = RB_HALT|RB_BOOTLOADER;
+	else if (strcmp(myname, "bootloader") == 0)
+		howto = RB_HALT|RB_BOOTLOADER;
 	else
 		howto = 0;
 
@@ -96,7 +100,7 @@ main(argc, argv)
 			user = "root";
 		openlog(myname, 0, LOG_AUTH);
 		syslog(LOG_CRIT, "%s; %s by %s",
- 			args, (howto&RB_HALT)?"halted":"rebooted", user);
+			args, (howto&RB_HALT)?"halted":"rebooted", user);
 	}
         /*
          * Do a sync early on so disks start transfers while we're killing
@@ -155,7 +159,6 @@ main(argc, argv)
 	exit(EX_OSERR);
 }
 
-
 /*
  * Make shutdown entry in /usr/adm/utmp.
  */
@@ -164,7 +167,7 @@ main(argc, argv)
 
 #define	SCPYN(a, b)	strncpy(a, b, sizeof(a))
 
-markdown()
+void markdown()
 {
 	struct utmp wtmp;
 	register int f = open(_PATH_WTMP, O_WRONLY|O_APPEND);
diff --git a/src/cmd/shutdown/shutdown.c b/src/cmd/shutdown/shutdown.c
index 52bd9e9..5ebc58a 100644
--- a/src/cmd/shutdown/shutdown.c
+++ b/src/cmd/shutdown/shutdown.c
@@ -20,6 +20,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <fcntl.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/param.h>
@@ -37,8 +38,6 @@
 
 char	hostname[MAXHOSTNAMELEN];
 
-time_t	getsdt();
-
 struct	utmp utmp;
 int	sint;
 long	stogo;
@@ -82,6 +81,10 @@ struct interval {
 
 char *shutter;
 
+static time_t getsdt(char *s);
+static void nolog(time_t sdt);
+static void doitfast(void);
+
 void finish(sig)
         int sig;
 {
@@ -96,13 +99,13 @@ void timeout(sig)
 	longjmp(alarmbuf, 1);
 }
 
-warning(term, sdt, now, type)
+void warning(term, sdt, now, type)
 	FILE *term;
 	time_t sdt, now;
 	char *type;
 {
 	char *ts;
-	register delay = sdt - now;
+	register int delay = sdt - now;
 
 	if (delay > 8)
 		while (delay % 5)
@@ -125,11 +128,11 @@ warning(term, sdt, now, type)
 		fprintf(term, "System going down IMMEDIATELY\r\n");
 }
 
-main(argc,argv)
+int main(argc,argv)
 	int argc;
 	char **argv;
 {
-	register i, ufd;
+	register int i, ufd;
 	register char *f;
 	char *ts;
 	time_t sdt;
@@ -147,7 +150,7 @@ main(argc,argv)
 	openlog("shutdown", 0, LOG_AUTH);
 	argc--, argv++;
 	while (argc > 0 && (f = argv[0], *f++ == '-')) {
-		while (i = *f++) switch (i) {
+		while ((i = *f++)) switch (i) {
 		case 'k':
 			killflg = 0;
 			continue;
@@ -209,7 +212,7 @@ main(argc,argv)
 	(void) setpriority(PRIO_PROCESS, 0, PRIO_MIN);
 	(void) fflush(stdout);
 #ifndef DEBUG
-	if (i = fork()) {
+	if ((i = fork())) {
 		printf("[pid %d]\n", i);
 		exit(0);
 	}
@@ -365,9 +368,10 @@ badform:
 	printf("Bad time format\n");
 	finish(0);
 	/*NOTREACHED*/
+	return 0;
 }
 
-doitfast()
+void doitfast()
 {
 	register FILE *fastd;
 
@@ -377,7 +381,7 @@ doitfast()
 	}
 }
 
-nolog(sdt)
+void nolog(sdt)
 	time_t sdt;
 {
 	register FILE *nologf;
diff --git a/src/cmd/update/update.c b/src/cmd/update/update.c
index 95a4960..597fa26 100644
--- a/src/cmd/update/update.c
+++ b/src/cmd/update/update.c
@@ -34,12 +34,17 @@
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 
-main()
+void mysync()
+{
+	(void)sync();
+}
+
+int main()
 {
 	struct itimerval value;
 	sigset_t set;
-	void mysync();
 
 	daemon(0, 0);
 
@@ -58,9 +63,3 @@ main()
 		sigsuspend(&set);
 	/* NOTREACHED */
 }
-
-void
-mysync()
-{
-	(void)sync();
-}
diff --git a/src/cmd/vipw/vipw.c b/src/cmd/vipw/vipw.c
index ab7312a..2a313f0 100644
--- a/src/cmd/vipw/vipw.c
+++ b/src/cmd/vipw/vipw.c
@@ -20,6 +20,7 @@
 #include <sys/file.h>
 #include <sys/time.h>
 #include <sys/resource.h>
+#include <sys/wait.h>
 #include <errno.h>
 #include <pwd.h>
 #include <stdio.h>
@@ -29,10 +30,17 @@
 #include <unistd.h>
 #include <limits.h>
 #include <paths.h>
+#include <fcntl.h>
 
 char *passwd, *temp;
 
-main()
+static void stop(int val);
+static int edit(void);
+static int check(FILE *tfp);
+static int prompt(void);
+static int makedb(char *file);
+
+int main()
 {
 	register int n, fd_passwd, fd;
 	struct rlimit rlim;
@@ -143,7 +151,7 @@ syserr:		(void)fprintf(stderr, "vipw: %s: %s; ",
 	exit(0);
 }
 
-check(tfp)
+int check(tfp)
 	FILE *tfp;
 {
 	long id;
@@ -190,7 +198,7 @@ check(tfp)
 		if (!(p = strsep(&bp, ":")))	/* shell */
 			goto general;
 		if (root && *p)				/* empty == /bin/sh */
-			for (setusershell();;)
+			for (setusershell();;) {
 				if (!(sh = getusershell())) {
 					(void)fprintf(stderr,
 					    "vipw: warning, unknown root shell.\n");
@@ -198,6 +206,7 @@ check(tfp)
 				}
 				else if (!strcmp(p, sh))
 					break;
+                        }
 		if (strsep(&bp, ":")) {	/* too many */
 general:		(void)fprintf(stderr, "vipw: corrupted entry");
 bad:			(void)fprintf(stderr, "; line #%d.\n", lcnt);
@@ -208,7 +217,7 @@ bad:			(void)fprintf(stderr, "; line #%d.\n", lcnt);
 	return(0);
 }
 
-makedb(file)
+int makedb(file)
 	char *file;
 {
 	int status, pid, w;
@@ -221,13 +230,13 @@ makedb(file)
 	return(w == -1 || status);
 }
 
-edit()
+int edit()
 {
 	int status, pid, w;
 	char *p, *editor;
 
-	if (editor = getenv("EDITOR")) {
-		if (p = rindex(editor, '/'))
+	if ((editor = getenv("EDITOR"))) {
+		if ((p = rindex(editor, '/')))
 			++p;
 		else
 			p = editor;
@@ -244,7 +253,7 @@ edit()
 	return(w == -1 || status);
 }
 
-prompt()
+int prompt()
 {
 	register int c;
 
@@ -259,7 +268,7 @@ prompt()
 	/* NOTREACHED */
 }
 
-stop(val)
+void stop(val)
 	int val;
 {
 	(void)fprintf(stderr, "%s unchanged.\n", passwd);
diff --git a/src/cmd/virus/Makefile b/src/cmd/virus/Makefile
index 8dbdedf..a604fc8 100644
--- a/src/cmd/virus/Makefile
+++ b/src/cmd/virus/Makefile
@@ -3,8 +3,8 @@ include $(TOPSRC)/target.mk
 
 CFLAGS          += -Wall -Werror -Os
 
-virus:          virus.c
-		$(CC) $(LDFLAGS) -o virus.elf virus.c $(LIBS) -ltermcap
+virus:          virus.o
+		$(LD) $(LDFLAGS) -o virus.elf virus.o $(LIBS) -ltermcap
 		$(SIZE) virus.elf
 		$(ELF2AOUT) virus.elf $@
 
diff --git a/sys/include/mount.h b/sys/include/mount.h
index 540b068..9bae6b0 100644
--- a/sys/include/mount.h
+++ b/sys/include/mount.h
@@ -100,5 +100,6 @@ int getfsstat(struct statfs *buf, int bufsize, unsigned flags);
 int getmntinfo(struct statfs **mntbufp, int flags);
 int statfs(const char *path, struct statfs *buf);
 int mount(const char *source, const char *target, int mountflags);
+int umount(const char *target);
 
 #endif