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path: root/init/do_mounts_initrd.c
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Diffstat (limited to 'init/do_mounts_initrd.c')
-rw-r--r--init/do_mounts_initrd.c121
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 00000000000..07e7d31f2d0
--- /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;
+}