Fix parse_numeric() to ignore non hex root string prefixes

On OLPC machines, root is a nand device that is mounted as mtd0 (it is
neither a block device nor a char device).  The arguments passed to the
kernel are "ro root=mtd0 rootfstype=jffs2".

Unfortunately, attempting to use an initrd based upon initramfs-tools
on such a machine results in a kernel panic and a syntax error.


Begin: Mounting root file system ... /init: line 172: syntax error:
0xmtd0

The probably appears to be in parse_numeric(); the init scripts
assume that normal devices are always prefixed with /, and root=
strings that aren't are raw device numbers (prefixing them with
0x).  I'm not sure if there are other devices similar to mtd that
don't begin with a /.

How about something like the following patch? It's not foolproof,
but it at least ignores things that can't possibly be hex strings.
fixes partially #497133

1 files changed, 4 insertions, 1 deletions

diff --git a/scripts/functions b/scripts/functions
index 5d81afd..299c29c 100644
--- a/scripts/functions
+++ b/scripts/functions
@@ -242,11 +242,14 @@ parse_numeric() {
 		minor=${1#*:}
 		major=${1%:*}
 		;;
-	*)
+	[A-Fa-f0-9]*)
 		value=$(( 0x${1} ))
 		minor=$(( ${value} % 256 ))
 		major=$(( ${value} / 256 ))
 		;;
+	*)
+		return
+		;;
 	esac
 
 	mknod -m 600 /dev/root b ${major} ${minor}