[PATCH] Add rdinit parameter to pick early userspace init

Since early userspace was added, there's no way to override which init to
run from it.  Some people tack on an extra cpio archive with a link from
/init depending on what they want to run, but that's sometimes impractical.

Changing the "init=" to also override the early userspace isn't feasible,
since it is still used to indicate what init to run from disk when early
userspace has completed doing whatever it's doing (i.e.  load filesystem
modules and drivers).

Instead, introduce "rdinit=" and make it override the default "/init" if
specified.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 3d5cd7a09b2f..d2f0c67ba1fb 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1174,6 +1174,11 @@ running once the system is up.
                         New name for the ramdisk parameter.
                         See Documentation/ramdisk.txt.
 
+        rdinit=         [KNL]
+                        Format: <full_path>
+                        Run specified binary instead of /init from the ramdisk,
+                        used for early userspace startup. See initrd.
+
         reboot=         [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
                         Format: <reboot_mode>[,<reboot_mode2>[,...]]
                         See arch/*/kernel/reboot.c.