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
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);
38	return kernel_execve(shell, argv, envp_init);
39}
40
41static 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	pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
59	if (pid > 0) {
60		while (pid != sys_wait4(-1, NULL, 0, NULL)) {
61			try_to_freeze();
62			yield();
63		}
64	}
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);
74
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);
89		if (error == -ENOENT)
90			printk("/initrd does not exist. Ignored.\n");
91		else
92			printk("failed\n");
93		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) {
109		create_dev("/dev/ram", Root_RAM0);
110		/*
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}
125