blob: b222ce9e1c8bd3e4871acf564d187225ba0e574c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#include <linux/unistd.h>
2#include <linux/kernel.h>
3#include <linux/fs.h>
4#include <linux/minix_fs.h>
5#include <linux/ext2_fs.h>
6#include <linux/romfs_fs.h>
7#include <linux/initrd.h>
8#include <linux/sched.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -08009#include <linux/freezer.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010
11#include "do_mounts.h"
12
13unsigned long initrd_start, initrd_end;
14int initrd_below_start_ok;
15unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
16static int __initdata old_fd, root_fd;
17static int __initdata mount_initrd = 1;
18
19static int __init no_initrd(char *str)
20{
21 mount_initrd = 0;
22 return 1;
23}
24
25__setup("noinitrd", no_initrd);
26
27static int __init do_linuxrc(void * shell)
28{
29 static char *argv[] = { "linuxrc", NULL, };
30 extern char * envp_init[];
31
32 sys_close(old_fd);sys_close(root_fd);
33 sys_close(0);sys_close(1);sys_close(2);
34 sys_setsid();
35 (void) sys_open("/dev/console",O_RDWR,0);
36 (void) sys_dup(0);
37 (void) sys_dup(0);
Arnd Bergmann67608562006-10-02 02:18:26 -070038 return kernel_execve(shell, argv, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039}
40
41static void __init handle_initrd(void)
42{
43 int error;
Domen Puncer29a1d2d2005-06-25 14:58:43 -070044 int pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
46 real_root_dev = new_encode_dev(ROOT_DEV);
Greg Kroah-Hartmanbdaf8522005-06-20 21:15:16 -070047 create_dev("/dev/root.old", Root_RAM0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 /* mount initrd on rootfs' /root */
49 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
50 sys_mkdir("/old", 0700);
51 root_fd = sys_open("/", 0, 0);
52 old_fd = sys_open("/old", 0, 0);
53 /* move initrd over / and chdir/chroot in initrd root */
54 sys_chdir("/root");
55 sys_mount(".", "/", NULL, MS_MOVE, NULL);
56 sys_chroot(".");
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58 pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
59 if (pid > 0) {
Rafael J. Wysocki726162b2007-05-06 14:50:46 -070060 while (pid != sys_wait4(-1, NULL, 0, NULL)) {
61 try_to_freeze();
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 yield();
Rafael J. Wysocki726162b2007-05-06 14:50:46 -070063 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 }
65
66 /* move initrd to rootfs' /old */
67 sys_fchdir(old_fd);
68 sys_mount("/", ".", NULL, MS_MOVE, NULL);
69 /* switch root and cwd back to / of rootfs */
70 sys_fchdir(root_fd);
71 sys_chroot(".");
72 sys_close(old_fd);
73 sys_close(root_fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75 if (new_decode_dev(real_root_dev) == Root_RAM0) {
76 sys_chdir("/old");
77 return;
78 }
79
80 ROOT_DEV = new_decode_dev(real_root_dev);
81 mount_root();
82
83 printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
84 error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
85 if (!error)
86 printk("okay\n");
87 else {
88 int fd = sys_open("/dev/root.old", O_RDWR, 0);
Jay Lanf220ab22005-06-30 02:59:03 -070089 if (error == -ENOENT)
90 printk("/initrd does not exist. Ignored.\n");
91 else
92 printk("failed\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 printk(KERN_NOTICE "Unmounting old root\n");
94 sys_umount("/old", MNT_DETACH);
95 printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
96 if (fd < 0) {
97 error = fd;
98 } else {
99 error = sys_ioctl(fd, BLKFLSBUF, 0);
100 sys_close(fd);
101 }
102 printk(!error ? "okay\n" : "failed\n");
103 }
104}
105
106int __init initrd_load(void)
107{
108 if (mount_initrd) {
Greg Kroah-Hartmanbdaf8522005-06-20 21:15:16 -0700109 create_dev("/dev/ram", Root_RAM0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 /*
111 * Load the initrd data into /dev/ram0. Execute it as initrd
112 * unless /dev/ram0 is supposed to be our actual root device,
113 * in that case the ram disk is just set up here, and gets
114 * mounted in the normal path.
115 */
116 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
117 sys_unlink("/initrd.image");
118 handle_initrd();
119 return 1;
120 }
121 }
122 sys_unlink("/initrd.image");
123 return 0;
124}