Creation of Cybook 2416 (actually Gen4) repository

init/do_mounts_initrd.c

@@ -0,0 +1,123 @@
+#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;
+}