Add /sys/src/9/boot/tread, a tool to read a line with a timeout.

While here, remove boot(8) references to pcload.

sys/src/9/boot/bootmkfile

@@ -16,3 +16,7 @@ $BOOTFILES:	$BOOTDIR/boot.h
 
 %.$O:	$BOOTDIR/%.c
 	$CC -I$BOOTDIR $CFLAGS $BOOTDIR/$stem.c
+
+tread: tread.c
+	$CC tread.c
+	$LD -o tread tread.8

sys/src/9/boot/bootrc

@@ -67,22 +67,17 @@ fn readmethod{
 		timeo=5
 		resp=()
 		while(~ $#resp 0){
-			if(~ $#pcload 0)
-				echo -n 'root is from: '
-			if not
-				echo -n 'kernel is at: '
-			resp=`{read}
+			echo -n 'root is from: '
+			resp=`{tread $timeo}
 			if(! ~ $status ''){
 				bootconf	# set configuration from file
 				if(! ~ $#nobootprompt 0)
 					bootargs=$nobootprompt
 				resp=$bootargs
 			}
-			if(~ $resp !rc){
+			if(~ $resp !rc)
 				rc -i
-				resp=()
-			}
-			timo=0
+			timeo=0
 		}
 
 		method=`{echo $resp | awk -F! '{print $1}'}
@@ -103,9 +98,6 @@ fn readmethod{
 
 fn authentication{
 	if(! test -f /srv/factotum){
-		# in pcload we only need to read the kernel
-		if(~ $pcload 1)
-			user=none
 		x=(auth/factotum -sfactotum)
 		if(~ $cpuflag 1)
 			x=($x -kS)
@@ -142,10 +134,6 @@ fn main{
 	$mp($connect)
 
 	must mount -c /srv/boot /root
-	if(~ $pcload 1){
-		echo reboot /root/$kern >/dev/reboot
-		fatal kernel load failed: $kern
-	}
 
 	swapproc
 

sys/src/9/boot/conf.rc

@@ -28,8 +28,7 @@ fn confmount{
 }
 
 fn findconf{
-	# search cd/dvd drives first
-	for(d in $cddevs /dev/sd* /dev/fd*disk)
+	for(d in /dev/sd*)
 	for(p in `{ls $d}){
 		if(~ $found 0){
 			confmount $p

sys/src/9/boot/local.rc

@@ -5,13 +5,6 @@ fn configlocal{
 	fstype=`{echo $disk | sed 's,.*/(.*)$,\1,g'}
 	disk=`{echo $disk | sed 's,(.*)/.*$,\1,'}
 
-	if(~ $pcload 1){
-		kern=`{echo $methodarg | sed 's,.*!(.*)$,\1,g'}
-
-		# for now we only allow kernels in the same dev/part of $methodargs
-		if(~ $#kern 0 || ! ~ $#bootfile 0)
-			kern=`{echo $bootfile | sed 's,.*!(.*)$,\1,g'}
-	}
 	diskparts
 }
 

sys/src/9/boot/tread.c

@@ -0,0 +1,73 @@
+#include <u.h>
+#include <libc.h>
+
+int c;
+
+int
+alarmed(void *a, char *msg)
+{
+	USED(a);
+	USED(msg);
+	if(!c)
+		exits("timedout");
+	noted(NCONT);
+	return 1;
+}
+
+void
+readline(int fd, char *buf, int nbuf)
+{
+	int i, n;
+
+	i = 0;
+	while(i < nbuf-1){
+		n = read(fd, &c, sizeof c);
+		alarm(0);
+		c &= 0xff;
+		write(fd, &c, 1);
+		if(n != 1 || c == '\04' || c == '\177'){
+			i = 0;
+			break;
+		} else if(c == '\n')
+			break;
+		else if(c == '\b' && i > 0)
+			--i;
+		else if(c == ('u' & 037)){
+			c = '\b';
+			for(n=0; n <= i; n++)
+				write(fd, &c, 1);
+			i = 0;
+		} else
+			buf[i++] = c;
+	}
+	buf[i] = 0;
+}
+
+void
+main(int argc, char *argv[])
+{
+	int fd, ctl, i;
+	char buf[256];
+	long n;
+
+	if(argc < 2)
+		sysfatal("usage: tread timeout");
+
+	atnotify(alarmed, 1);
+
+	fd = open("/dev/cons", ORDWR);
+	if(fd < 0)
+		sysfatal("open cons: %r");
+	ctl = open("/dev/consctl", OWRITE);
+	if(ctl < 0)
+		sysfatal("open consctl: %r");
+
+	write(ctl, "rawon", 5);
+	alarm(atoi(argv[1])*1000);
+
+	readline(fd, buf, sizeof(buf));
+	close(ctl);
+	close(fd);
+	print("%s", buf);
+	exits(nil);
+}

sys/src/9/port/bootfs.proto

@@ -30,6 +30,7 @@ $cputype
 		seq
 		srv
 		test
+		tread	555 sys sys ../boot/tread
 		unmount
 		usb
 			usbd

sys/src/9/port/mkbootfs

@@ -33,6 +33,11 @@ fn rootbz2 {
 	rm boot.bz2
 }
 
+@{cd ../boot
+	. /$cputype/mkfile
+	mk -f bootmkfile tread
+}
+
 bootraw
 bootbz2
 rootbz2