blob: 2b108538d0d95684be2048fcc80a7acf484970c4 [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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 sys_setsid();
Arnd Bergmann67608562006-10-02 02:18:26 -070034 return kernel_execve(shell, argv, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -070035}
36
37static void __init handle_initrd(void)
38{
39 int error;
Domen Puncer29a1d2d2005-06-25 14:58:43 -070040 int pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
42 real_root_dev = new_encode_dev(ROOT_DEV);
Greg Kroah-Hartmanbdaf8522005-06-20 21:15:16 -070043 create_dev("/dev/root.old", Root_RAM0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 /* mount initrd on rootfs' /root */
45 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
46 sys_mkdir("/old", 0700);
47 root_fd = sys_open("/", 0, 0);
48 old_fd = sys_open("/old", 0, 0);
49 /* move initrd over / and chdir/chroot in initrd root */
50 sys_chdir("/root");
51 sys_mount(".", "/", NULL, MS_MOVE, NULL);
52 sys_chroot(".");
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
Rafael J. Wysocki8baabde2007-11-21 02:50:17 +010054 /*
55 * In case that a resume from disk is carried out by linuxrc or one of
56 * its children, we need to tell the freezer not to wait for us.
57 */
58 current->flags |= PF_FREEZER_SKIP;
59
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
Rafael J. Wysocki83144182007-07-17 04:03:35 -070061 if (pid > 0)
Rafael J. Wysocki8baabde2007-11-21 02:50:17 +010062 while (pid != sys_wait4(-1, NULL, 0, NULL))
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 yield();
Rafael J. Wysocki8baabde2007-11-21 02:50:17 +010064
65 current->flags &= ~PF_FREEZER_SKIP;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67 /* move initrd to rootfs' /old */
68 sys_fchdir(old_fd);
69 sys_mount("/", ".", NULL, MS_MOVE, NULL);
70 /* switch root and cwd back to / of rootfs */
71 sys_fchdir(root_fd);
72 sys_chroot(".");
73 sys_close(old_fd);
74 sys_close(root_fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76 if (new_decode_dev(real_root_dev) == Root_RAM0) {
77 sys_chdir("/old");
78 return;
79 }
80
81 ROOT_DEV = new_decode_dev(real_root_dev);
82 mount_root();
83
84 printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
85 error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
86 if (!error)
87 printk("okay\n");
88 else {
89 int fd = sys_open("/dev/root.old", O_RDWR, 0);
Jay Lanf220ab22005-06-30 02:59:03 -070090 if (error == -ENOENT)
91 printk("/initrd does not exist. Ignored.\n");
92 else
93 printk("failed\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 printk(KERN_NOTICE "Unmounting old root\n");
95 sys_umount("/old", MNT_DETACH);
96 printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
97 if (fd < 0) {
98 error = fd;
99 } else {
100 error = sys_ioctl(fd, BLKFLSBUF, 0);
101 sys_close(fd);
102 }
103 printk(!error ? "okay\n" : "failed\n");
104 }
105}
106
107int __init initrd_load(void)
108{
109 if (mount_initrd) {
Greg Kroah-Hartmanbdaf8522005-06-20 21:15:16 -0700110 create_dev("/dev/ram", Root_RAM0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 /*
112 * Load the initrd data into /dev/ram0. Execute it as initrd
113 * unless /dev/ram0 is supposed to be our actual root device,
114 * in that case the ram disk is just set up here, and gets
115 * mounted in the normal path.
116 */
117 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
118 sys_unlink("/initrd.image");
119 handle_initrd();
120 return 1;
121 }
122 }
123 sys_unlink("/initrd.image");
124 return 0;
125}