1 #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>
9 #include <linux/freezer.h>
10
11 #include "do_mounts.h"
12
13 unsigned long initrd_start, initrd_end;
14 int initrd_below_start_ok;
15 unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
16 static int __initdata old_fd, root_fd;
17 static int __initdata mount_initrd = 1;
18
no_initrd(char * str)19 static int __init no_initrd(char *str)
20 {
21 mount_initrd = 0;
22 return 1;
23 }
24
25 __setup("noinitrd", no_initrd);
26
do_linuxrc(void * shell)27 static 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);
38 return kernel_execve(shell, argv, envp_init);
39 }
40
handle_initrd(void)41 static void __init handle_initrd(void)
42 {
43 int error;
44 int pid;
45
46 real_root_dev = new_encode_dev(ROOT_DEV);
47 create_dev("/dev/root.old", Root_RAM0);
48 /* 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(".");
57
58 /*
59 * In case that a resume from disk is carried out by linuxrc or one of
60 * its children, we need to tell the freezer not to wait for us.
61 */
62 current->flags |= PF_FREEZER_SKIP;
63
64 pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
65 if (pid > 0)
66 while (pid != sys_wait4(-1, NULL, 0, NULL))
67 yield();
68
69 current->flags &= ~PF_FREEZER_SKIP;
70
71 /* move initrd to rootfs' /old */
72 sys_fchdir(old_fd);
73 sys_mount("/", ".", NULL, MS_MOVE, NULL);
74 /* switch root and cwd back to / of rootfs */
75 sys_fchdir(root_fd);
76 sys_chroot(".");
77 sys_close(old_fd);
78 sys_close(root_fd);
79
80 if (new_decode_dev(real_root_dev) == Root_RAM0) {
81 sys_chdir("/old");
82 return;
83 }
84
85 ROOT_DEV = new_decode_dev(real_root_dev);
86 mount_root();
87
88 printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
89 error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
90 if (!error)
91 printk("okay\n");
92 else {
93 int fd = sys_open("/dev/root.old", O_RDWR, 0);
94 if (error == -ENOENT)
95 printk("/initrd does not exist. Ignored.\n");
96 else
97 printk("failed\n");
98 printk(KERN_NOTICE "Unmounting old root\n");
99 sys_umount("/old", MNT_DETACH);
100 printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
101 if (fd < 0) {
102 error = fd;
103 } else {
104 error = sys_ioctl(fd, BLKFLSBUF, 0);
105 sys_close(fd);
106 }
107 printk(!error ? "okay\n" : "failed\n");
108 }
109 }
110
initrd_load(void)111 int __init initrd_load(void)
112 {
113 if (mount_initrd) {
114 create_dev("/dev/ram", Root_RAM0);
115 /*
116 * Load the initrd data into /dev/ram0. Execute it as initrd
117 * unless /dev/ram0 is supposed to be our actual root device,
118 * in that case the ram disk is just set up here, and gets
119 * mounted in the normal path.
120 */
121 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
122 sys_unlink("/initrd.image");
123 handle_initrd();
124 return 1;
125 }
126 }
127 sys_unlink("/initrd.image");
128 return 0;
129 }
130