debvm-run: expand the rootdev skip

1 files changed, 30 insertions, 11 deletions

diff --git a/bin/debvm-run b/bin/debvm-run
index ead9942..d8ff174 100755
--- a/bin/debvm-run
+++ b/bin/debvm-run
@@ -52,11 +52,20 @@ Do not pass configure network card.
 
 Do not pass a random number generator device.
 
-=item B<rootdev>
+=item B<root>
+
+Skip all of the following tasks matching C<root/*>.
+If either of these is present, the VM will not boot unless a suitable replacement is added in another way.
+
+=item B<root/cmd>
+
+Since B<debvm-run> uses B<qemu> as bootloader it normally passes the label of the root block device via the kernel command line.
+This passing can be inhibited to supply a different location.
+
+=item B<root/dev>
 
 A block device for the root filesystem is no longer passed.
 This can be used to customize the block device.
-The label of the root filesystem will still be passed.
 
 =back
 
@@ -208,10 +217,15 @@ if ! printf '\123\357' | cmp --bytes=2 "$IMAGE" - 1080; then
 fi
 
 check_skip() {
-	case "$SKIP" in
-		*",$1,"*)	return 0 ;;
-		*)		return 1 ;;
-	esac
+	while :; do
+		case "$SKIP" in
+			*",$1,"*)	return 0 ;;
+		esac
+		if test "$1" = "${1%/*}"; then
+			return 1
+		fi
+		set -- "${1%/*}"
+	done
 }
 
 cleanup() {
@@ -279,7 +293,10 @@ case "$IMAGE_LABEL" in
 	;;
 esac
 
-KERNEL_CMDLINE="root=LABEL=$IMAGE_LABEL rw"
+KERNEL_CMDLINE=
+if ! check_skip root/cmd; then
+	KERNEL_CMDLINE="root=LABEL=$IMAGE_LABEL rw"
+fi
 NETDEV="user,id=net0"
 
 KERNELFD=3
@@ -304,7 +321,7 @@ set -- \
 	-initrd "/proc/self/fd/$INITRDFD" \
 	"$@"
 
-if ! check_skip rootdev; then
+if ! check_skip root/dev; then
 	set -- \
 		-drive "media=disk,format=raw,discard=unmap,file=$IMAGE,if=virtio,cache=unsafe" \
 		"$@"
@@ -409,11 +426,11 @@ if test -z "$GRAPHICAL"; then
 	set -- -nographic "$@"
 	case "$KERNELARCH" in
 		amd64|i386)
-			KERNEL_CMDLINE="$KERNEL_CMDLINE console=ttyS0"
+			KERNEL_CMDLINE="${KERNEL_CMDLINE:+"$KERNEL_CMDLINE "}console=ttyS0"
 		;;
 	esac
 	if test -t 0 && test -t 1 && test -n "$TERM"; then
-		KERNEL_CMDLINE="$KERNEL_CMDLINE TERM=$TERM"
+		KERNEL_CMDLINE="${KERNEL_CMDLINE:+"$KERNEL_CMDLINE "}TERM=$TERM"
 	fi
 else
 	case "$KERNELARCH" in
@@ -440,7 +457,9 @@ DNSSEARCH=$(dnsdomainname)
 if test -n "$DNSSEARCH"; then
 	NETDEV="$NETDEV,domainname=$DNSSEARCH"
 fi
-set -- -append "$KERNEL_CMDLINE" "$@"
+if test -n "$KERNEL_CMDLINE"; then
+	set -- -append "$KERNEL_CMDLINE" "$@"
+fi
 
 if ! check_skip network; then
 	set -- -netdev "$NETDEV" -device "$NIC_DEV" "$@"