1 #define __KERNEL_SYSCALLS__ 2 #include <linux/unistd.h> 3 #include <linux/kernel.h> 4 #include <linux/fs.h> 5 #include <linux/minix_fs.h> 6 #include <linux/ext2_fs.h> 7 #include <linux/romfs_fs.h> 8 #include <linux/initrd.h> 9 #include <linux/sched.h> 10 11 #include "do_mounts.h" 12 13 unsigned long initrd_start, initrd_end; 14 int initrd_below_start_ok; 15 unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */ 16 static int __initdata old_fd, root_fd; 17 static int __initdata mount_initrd = 1; 18 19 static int __init no_initrd(char *str) 20 { 21 mount_initrd = 0; 22 return 1; 23 } 24 25 __setup("noinitrd", no_initrd); 26 27 static 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 execve(shell, argv, envp_init); 39 } 40 41 static 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 current->flags |= PF_NOFREEZE; 59 pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD); 60 if (pid > 0) { 61 while (pid != sys_wait4(-1, NULL, 0, NULL)) 62 yield(); 63 } 64 65 /* move initrd to rootfs' /old */ 66 sys_fchdir(old_fd); 67 sys_mount("/", ".", NULL, MS_MOVE, NULL); 68 /* switch root and cwd back to / of rootfs */ 69 sys_fchdir(root_fd); 70 sys_chroot("."); 71 sys_close(old_fd); 72 sys_close(root_fd); 73 74 if (new_decode_dev(real_root_dev) == Root_RAM0) { 75 sys_chdir("/old"); 76 return; 77 } 78 79 ROOT_DEV = new_decode_dev(real_root_dev); 80 mount_root(); 81 82 printk(KERN_NOTICE "Trying to move old root to /initrd ... "); 83 error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL); 84 if (!error) 85 printk("okay\n"); 86 else { 87 int fd = sys_open("/dev/root.old", O_RDWR, 0); 88 if (error == -ENOENT) 89 printk("/initrd does not exist. Ignored.\n"); 90 else 91 printk("failed\n"); 92 printk(KERN_NOTICE "Unmounting old root\n"); 93 sys_umount("/old", MNT_DETACH); 94 printk(KERN_NOTICE "Trying to free ramdisk memory ... "); 95 if (fd < 0) { 96 error = fd; 97 } else { 98 error = sys_ioctl(fd, BLKFLSBUF, 0); 99 sys_close(fd); 100 } 101 printk(!error ? "okay\n" : "failed\n"); 102 } 103 } 104 105 int __init initrd_load(void) 106 { 107 if (mount_initrd) { 108 create_dev("/dev/ram", Root_RAM0); 109 /* 110 * Load the initrd data into /dev/ram0. Execute it as initrd 111 * unless /dev/ram0 is supposed to be our actual root device, 112 * in that case the ram disk is just set up here, and gets 113 * mounted in the normal path. 114 */ 115 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) { 116 sys_unlink("/initrd.image"); 117 handle_initrd(); 118 return 1; 119 } 120 } 121 sys_unlink("/initrd.image"); 122 return 0; 123 } 124