1 files changed, 121 insertions, 0 deletions

diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
new file mode 100644
index 000000000000..07e7d31f2d0b
--- /dev/null
+++ b/init/do_mounts_initrd.c
@@ -0,0 +1,121 @@
+#define __KERNEL_SYSCALLS__
+#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 "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 execve(shell, argv, envp_init);
+}
+
+static void __init handle_initrd(void)
+{
+        int error;
+        int i, pid;
+
+        real_root_dev = new_encode_dev(ROOT_DEV);
+        create_dev("/dev/root.old", Root_RAM0, NULL);
+        /* 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(".");
+        mount_devfs_fs ();
+
+        pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
+        if (pid > 0) {
+                while (pid != sys_wait4(-1, &i, 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);
+        umount_devfs("/old/dev");
+
+        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);
+                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, NULL);
+                /*
+                 * 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;
+}