boot: partitioning USB disks, mounting 9front.iso from FAT partition

sys/src/9/boot/bootrc

@@ -3,6 +3,7 @@ rfork e
 mt=()
 . /rc/lib/tcp.rc
 . /rc/lib/local.rc
+. /rc/lib/usb.rc
 
 fn fatal {
 	echo $*
@@ -55,6 +56,7 @@ fn getmethod{
 
 fn main{
 	rm -f /srv/boot
+	rm -f /srv/usb
 
 	getmethod
 
@@ -138,6 +140,7 @@ if(! ~ $#kbmap 0){
 		cat $"kbmap >/dev/kbmap
 }
 
+configusb		# run partfs on usb disks
 configlocal	# add partitions and binds
 
 while()@{

sys/src/9/boot/usb.rc

@@ -0,0 +1,24 @@
+fn configusb{
+	for(c in /dev/sdU*[0-9]){
+		d=`{echo $c | sed 's,^/dev/(.*),\1p,g'}
+		if(! test -d /dev/$d)
+			disk/partfs -d $d $c/data
+	}
+}
+
+fn connectusb{
+	m=/mnt/usb
+	if(! test -r $1)
+		fatal device $1 does not exist
+	if(! test -r $1/dos)
+		fatal device $1 does not have dos partition
+	mkdir -p $m
+	dossrv -r -f $1/dos usb
+	mount /srv/usb $m
+	if(! test -r $m/9front.iso)
+		fatal $m/9front.iso not found
+	{9660srv -s -f $m/9front.iso &} <[0=1] | echo 0 >/srv/boot
+}
+
+musb=(configusb connectusb)
+mt=(musb $mt)

sys/src/9/port/bootfs.proto

@@ -10,6 +10,7 @@ $cputype
 			fdisk
 			kfs
 			prep
+			partfs
 		dossrv
 		echo
 		cwfs64x
@@ -19,6 +20,7 @@ $cputype
 		ip
 			ipconfig
 		ls
+		mkdir
 		mount
 		ramfs
 		rc
@@ -38,6 +40,7 @@ rc
 		rcmain
 		local.rc 555 sys sys ../boot/local.rc
 		tcp.rc 555 sys sys ../boot/tcp.rc
+		usb.rc 555 sys sys ../boot/usb.rc
 	bin
 		fstype
 		diskparts