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authorOlof Johansson <olof@lixom.net>2005-09-06 15:17:19 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-09-07 16:57:28 -0700
commitffdfc40976dda18d923cd001d44bf0ee55da1af4 (patch)
tree2503b81230c5b3ad0ff3926e1388267338fe24b8
parent2b579beec255d6589fabe51b60933d723630bcd4 (diff)
downloadlwn-ffdfc40976dda18d923cd001d44bf0ee55da1af4.tar.gz
lwn-ffdfc40976dda18d923cd001d44bf0ee55da1af4.zip
[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>
-rw-r--r--Documentation/kernel-parameters.txt5
-rw-r--r--init/main.c31
2 files changed, 32 insertions, 4 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.
diff --git a/init/main.c b/init/main.c
index e4dbcbcd26cf..f142d4035341 100644
--- a/init/main.c
+++ b/init/main.c
@@ -123,6 +123,7 @@ extern void softirq_init(void);
char saved_command_line[COMMAND_LINE_SIZE];
static char *execute_command;
+static char *ramdisk_execute_command;
/* Setup configured maximum number of CPUs to activate */
static unsigned int max_cpus = NR_CPUS;
@@ -297,6 +298,18 @@ static int __init init_setup(char *str)
}
__setup("init=", init_setup);
+static int __init rdinit_setup(char *str)
+{
+ unsigned int i;
+
+ ramdisk_execute_command = str;
+ /* See "auto" comment in init_setup */
+ for (i = 1; i < MAX_INIT_ARGS; i++)
+ argv_init[i] = NULL;
+ return 1;
+}
+__setup("rdinit=", rdinit_setup);
+
extern void setup_arch(char **);
#ifndef CONFIG_SMP
@@ -681,10 +694,14 @@ static int init(void * unused)
* check if there is an early userspace init. If yes, let it do all
* the work
*/
- if (sys_access((const char __user *) "/init", 0) == 0)
- execute_command = "/init";
- else
+
+ if (!ramdisk_execute_command)
+ ramdisk_execute_command = "/init";
+
+ if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
+ ramdisk_execute_command = NULL;
prepare_namespace();
+ }
/*
* Ok, we have completed the initial bootup, and
@@ -701,7 +718,13 @@ static int init(void * unused)
(void) sys_dup(0);
(void) sys_dup(0);
-
+
+ if (ramdisk_execute_command) {
+ run_init_process(ramdisk_execute_command);
+ printk(KERN_WARNING "Failed to execute %s\n",
+ ramdisk_execute_command);
+ }
+
/*
* We try each of these until one succeeds.
*