1 README
2 ======
3
4 Description
5 -----------
6
7 Mkinitramfs is a shell script that will generate a cpio init ram filesystem.
8
9 The script itself simply checks for minimum required kernel capabilities,
10 recursively copies in useful applications and their library dependencies (using
11 ldd), and uses cpio to generate an init ram filesystem.
12
13 Note that this also includes an init script used for booting from the initrd
14 image, into the actual system. It includes support for dm-crypt encrypted root
15 volumes, as well as providing simple debugging capabilities.
16
17
18 Usage
19 -----
20
21 The script, mkinitramfs, creates a new init ram filesystem.
22
23 To use it, simply execute it, with the version of the kernel specified, and it
24 will create the initrd file, written to /boot/initrd-${version}. A
25 corresponding /boot/vmlinuz-${version} and /boot/System.map-${version} is
26 required. This version format is recognized by grub, so grub-mkconfig will
27 detect these files.
28
29 NOTE: This will overwrite the /boot/initrd-${version} file if it exists. If
30 you have something there that you want to keep, be sure to back it up before
31 running mkinitramfs.
32
33
34 Init Arguments
35 --------------
36
37 root
38 ~~~~
39 * *required*: yes
40 * *examples*:
41 ** root=/dev/sda3
42 ** root=UUID=92b74fd7-6e4f-4a52-ad40-fac874410ca3
43 ** root=LABEL=system
44
45 Path to the root device. Supports a dev path, LABEL, and UUID values. If device
46 is encrypted, the user will be prompted to decrypt it with a password. The
47 decrypted device will be mounted at _/dev/mapper/_dev_sda3_ (per the example).
48
49 NOTE: This only works with encrypted devices where the encrypted device
50 contains only a filesystem. If the encrypted device contains its own
51 partition table, see the _cryptroot_ directive.
52
53
54 cryptroot
55 ~~~~~~~~~
56 * *required*: no
57 * *examples*:
58 ** cryptroot=/dev/mapper/_sdap3
59 ** cryptroot=UUID=92b74fd7-6e4f-4a52-ad40-fac874410ca3
60 ** cryptroot=LABEL=system
61
62 Provides an alternate root device, set after decrypting the encrypted root
63 device. Only useful when the root directive is set. An example of using this
64 might be, root specifies a cryptluks device, that once decrypted, contains its
65 own partition table with partitions. This directive can be used to specify
66 which of those partitions is the system partition, after decryption has taken
67 place.
68
69 .Example
70 ----
71 root=/dev/sda3 cryptroot=/dev/mapper/_dev_sda3p1
72 ----
73
74 This example uses /dev/sda3 (which is a cryptluks device) as the original root.
75 The user is prompted to decrypt it with a password. After successful
76 decryption, the root device is reset to _dev_sda3p1, which is partition 1 of
77 the decrypted sda3 cryptluks device.
78
79
80 initdebug
81 ~~~~~~~~~
82 * *required*: no
83 * *examples*: NA
84
85 Enables step-by-step boot mode. Each step requires the user to hit the return
86 key.
87
88 NOTE: Enabling this will probably make the boot process go very slowly as it
89 requires a user response for every step.
90
91
92 interractive
93 ~~~~~~~~~~~~
94 * *required*: no
95 * *examples*: NA
96
97 Drops the user into an interractive shell, but before performing the first
98 mount operation, which is where most problems start to occur. This can be
99 useful for implementing new features in the init script, debugging problems,
100 checking the environment, etc.
|
