projects/linux·commit ffdfc409

[PATCH] Add rdinit parameter to pick early userspace init

ffdfc409 · Olof Johansson <[email protected]> · 2005-09-06 15:17:19 -07:00

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 <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Commit
ffdfc40976dda18d923cd001d44bf0ee55da1af4
Parents
2b579bee

Changes

2 files changed · +32 −4

FileStatusAddDelContent
Documentation/kernel-parameters.txtmodified+5−0View file
init/main.cmodified+27−4View file

Documentation/kernel-parameters.txt

View file
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 3d5cd7a..d2f0c67 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.

init/main.c

View file
diff --git a/init/main.c b/init/main.c
index e4dbcbc..f142d40 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.
*