1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/unistd.h>
3 #include <linux/kernel.h>
5 #include <linux/minix_fs.h>
6 #include <linux/romfs_fs.h>
7 #include <linux/initrd.h>
8 #include <linux/sched.h>
9 #include <linux/freezer.h>
10 #include <linux/kmod.h>
11 #include <uapi/linux/mount.h>
13 #include "do_mounts.h"
15 unsigned long initrd_start
, initrd_end
;
16 int initrd_below_start_ok
;
17 unsigned int real_root_dev
; /* do_proc_dointvec cannot handle kdev_t */
18 static int __initdata mount_initrd
= 1;
20 phys_addr_t phys_initrd_start __initdata
;
21 unsigned long phys_initrd_size __initdata
;
23 static int __init
no_initrd(char *str
)
29 __setup("noinitrd", no_initrd
);
31 static int __init
early_initrdmem(char *p
)
37 start
= memparse(p
, &endp
);
39 size
= memparse(endp
+ 1, NULL
);
41 phys_initrd_start
= start
;
42 phys_initrd_size
= size
;
46 early_param("initrdmem", early_initrdmem
);
48 static int __init
early_initrd(char *p
)
50 return early_initrdmem(p
);
52 early_param("initrd", early_initrd
);
54 static int init_linuxrc(struct subprocess_info
*info
, struct cred
*new)
56 ksys_unshare(CLONE_FS
| CLONE_FILES
);
58 /* move initrd over / and chdir/chroot in initrd root */
60 do_mount(".", "/", NULL
, MS_MOVE
, NULL
);
66 static void __init
handle_initrd(void)
68 struct subprocess_info
*info
;
69 static char *argv
[] = { "linuxrc", NULL
, };
70 extern char *envp_init
[];
73 real_root_dev
= new_encode_dev(ROOT_DEV
);
74 create_dev("/dev/root.old", Root_RAM0
);
75 /* mount initrd on rootfs' /root */
76 mount_block_root("/dev/root.old", root_mountflags
& ~MS_RDONLY
);
77 ksys_mkdir("/old", 0700);
81 * In case that a resume from disk is carried out by linuxrc or one of
82 * its children, we need to tell the freezer not to wait for us.
84 current
->flags
|= PF_FREEZER_SKIP
;
86 info
= call_usermodehelper_setup("/linuxrc", argv
, envp_init
,
87 GFP_KERNEL
, init_linuxrc
, NULL
, NULL
);
90 call_usermodehelper_exec(info
, UMH_WAIT_PROC
);
92 current
->flags
&= ~PF_FREEZER_SKIP
;
94 /* move initrd to rootfs' /old */
95 do_mount("..", ".", NULL
, MS_MOVE
, NULL
);
96 /* switch root and cwd back to / of rootfs */
99 if (new_decode_dev(real_root_dev
) == Root_RAM0
) {
105 ROOT_DEV
= new_decode_dev(real_root_dev
);
108 printk(KERN_NOTICE
"Trying to move old root to /initrd ... ");
109 error
= do_mount("/old", "/root/initrd", NULL
, MS_MOVE
, NULL
);
113 int fd
= ksys_open("/dev/root.old", O_RDWR
, 0);
114 if (error
== -ENOENT
)
115 printk("/initrd does not exist. Ignored.\n");
118 printk(KERN_NOTICE
"Unmounting old root\n");
119 ksys_umount("/old", MNT_DETACH
);
120 printk(KERN_NOTICE
"Trying to free ramdisk memory ... ");
124 error
= ksys_ioctl(fd
, BLKFLSBUF
, 0);
127 printk(!error
? "okay\n" : "failed\n");
131 bool __init
initrd_load(void)
134 create_dev("/dev/ram", Root_RAM0
);
136 * Load the initrd data into /dev/ram0. Execute it as initrd
137 * unless /dev/ram0 is supposed to be our actual root device,
138 * in that case the ram disk is just set up here, and gets
139 * mounted in the normal path.
141 if (rd_load_image("/initrd.image") && ROOT_DEV
!= Root_RAM0
) {
142 ksys_unlink("/initrd.image");
147 ksys_unlink("/initrd.image");