#include <linux/unistd.h>#include <linux/kernel.h>#include <linux/fs.h>#include <linux/minix_fs.h>#include <linux/ext2_fs.h>#include <linux/romfs_fs.h>#include <linux/initrd.h>#include <linux/sched.h>#include <linux/freezer.h> #include "do_mounts.h" unsigned long initrd_start, initrd_end;int initrd_below_start_ok;unsigned int real_root_dev;	/* do_proc_dointvec cannot handle kdev_t */static int __initdata old_fd, root_fd;static int __initdata mount_initrd = 1; static int __init no_initrd(char *str){	mount_initrd = 0;	return 1;} __setup("noinitrd", no_initrd); static int __init do_linuxrc(void * shell){	static char *argv[] = { "linuxrc", NULL, };	extern char * envp_init[]; 	sys_close(old_fd);sys_close(root_fd);	sys_close(0);sys_close(1);sys_close(2);	sys_setsid();	(void) sys_open("/dev/console",O_RDWR,0);	(void) sys_dup(0);	(void) sys_dup(0);	return kernel_execve(shell, argv, envp_init);} static void __init handle_initrd(void){	int error;	int pid; 	real_root_dev = new_encode_dev(ROOT_DEV);	create_dev("/dev/root.old", Root_RAM0);	/* mount initrd on rootfs' /root */	mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);	sys_mkdir("/old", 0700);	root_fd = sys_open("/", 0, 0);	old_fd = sys_open("/old", 0, 0);	/* move initrd over / and chdir/chroot in initrd root */	sys_chdir("/root");	sys_mount(".", "/", NULL, MS_MOVE, NULL);	sys_chroot("."); 	current->flags |= PF_NOFREEZE;	pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);	if (pid > 0) {		while (pid != sys_wait4(-1, NULL, 0, NULL))			yield();	} 	/* move initrd to rootfs' /old */	sys_fchdir(old_fd);	sys_mount("/", ".", NULL, MS_MOVE, NULL);	/* switch root and cwd back to / of rootfs */	sys_fchdir(root_fd);	sys_chroot(".");	sys_close(old_fd);	sys_close(root_fd); 	if (new_decode_dev(real_root_dev) == Root_RAM0) {		sys_chdir("/old");		return;	} 	ROOT_DEV = new_decode_dev(real_root_dev);	mount_root(); 	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");	error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);	if (!error)		printk("okay\n");	else {		int fd = sys_open("/dev/root.old", O_RDWR, 0);		if (error == -ENOENT)			printk("/initrd does not exist. Ignored.\n");		else			printk("failed\n");		printk(KERN_NOTICE "Unmounting old root\n");		sys_umount("/old", MNT_DETACH);		printk(KERN_NOTICE "Trying to free ramdisk memory ... ");		if (fd < 0) {			error = fd;		} else {			error = sys_ioctl(fd, BLKFLSBUF, 0);			sys_close(fd);		}		printk(!error ? "okay\n" : "failed\n");	}} int __init initrd_load(void){	if (mount_initrd) {		create_dev("/dev/ram", Root_RAM0);		/*		 * Load the initrd data into /dev/ram0. Execute it as initrd		 * unless /dev/ram0 is supposed to be our actual root device,		 * in that case the ram disk is just set up here, and gets		 * mounted in the normal path.		 */		if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {			sys_unlink("/initrd.image");			handle_initrd();			return 1;		}	}	sys_unlink("/initrd.image");	return 0;}