Bug#497133: initramfs-tools: explodes when kernel is booted

[Andres Salomon <dilinger@queued.net>]

Hi,

Along with an earlier submitted patch to include the mtd and jffs modules
in the initrd image, the attached patch is needed for booting with root=mtd0.
Basically, the init scripts assume the root device should have a special
device file somewhere, and if not will wait for it to appear.  This patch
changes it so that it only waits for a device file to appear if $ROOT starts
with "/dev".  In the case of things like ROOT=LABEL=foo, the init scripts
will translate that to a device.  With ROOT=mtd0, the init scripts will not
check for a device, and will successfully mount the root filesystem.

>From 586f67264971f0b8432aa99c13c9e16f009a729f Mon Sep 17 00:00:00 2001
From: Andres Salomon <dilinger@debian.org>
Date: Tue, 14 Oct 2008 18:04:09 -0400
Subject: [PATCH] allow root=mtd0 to be used

skip root checks if ROOT doesn't start with /dev.

Signed-off-by: Andres Salomon <dilinger@debian.org>
---
 debian/changelog |    2 ++
 scripts/local    |   14 ++++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/debian/changelog b/debian/changelog
index 833dcfa..4fdf762 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -4,6 +4,8 @@ initramfs-tools (0.92l.1) unstable; urgency=high
   * include mtd/jffs2/ubifs modules when 'most' is selected.
   * add support for linux-2.6's deb-pkg (via /etc/kernel).
   * include video (framebuffer, fbcon) modules when 'most' is selected.
+  * allow root=mtd0 to be used; skip root checks if ROOT doesn't start
+    with /dev.
 
  -- Andres Salomon <dilinger@debian.org>  Tue, 14 Oct 2008 14:16:50 -0400
 
diff --git a/scripts/local b/scripts/local
index 85d62af..b6bd192 100644
--- a/scripts/local
+++ b/scripts/local
@@ -24,8 +24,7 @@ get_fstype ()
 	return ${RET}
 }
 
-# Parameter: Where to mount the filesystem
-mountroot ()
+pre_mountroot()
 {
 	[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/local-top"
 	run_scripts /scripts/local-top
@@ -33,6 +32,12 @@ mountroot ()
 
 	wait_for_udev 10
 
+	# Don't wait for a root device that doesn't have a corresponding
+	# device in /dev (ie, mtd0)
+	if [ "${ROOT#/dev}" = "${ROOT}" ]; then
+		return
+	fi
+
 	# If the root device hasn't shown up yet, give it a little while
 	# to deal with removable devices
 	if [ ! -e "${ROOT}" ] || ! $(get_fstype "${ROOT}" >/dev/null); then
@@ -94,6 +99,11 @@ mountroot ()
 		echo " - Missing modules (cat /proc/modules; ls /dev)"
 		panic "ALERT!  ${ROOT} does not exist.  Dropping to a shell!"
 	done
+}
+
+mountroot()
+{
+	pre_mountroot
 
 	# Get the root filesystem type if not set
 	if [ -z "${ROOTFSTYPE}" ]; then
-- 
1.5.6.5