Kconfig 4.57 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
#
# Configuration for initramfs
#

config INITRAMFS_SOURCE
	string "Initramfs source file(s)"
	default ""
	help
	  This can be either a single cpio archive with a .cpio suffix or a
	  space-separated list of directories and files for building the
	  initramfs image.  A cpio archive should contain a filesystem archive
	  to be used as an initramfs image.  Directories should contain a
	  filesystem layout to be included in the initramfs image.  Files
	  should contain entries according to the format described by the
	  "usr/gen_init_cpio" program in the kernel tree.

	  When multiple directories and files are specified then the
	  initramfs image will be the aggregate of all of them.

20
	  See <file:Documentation/early-userspace/README> for more details.
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

	  If you are not sure, leave it blank.

config INITRAMFS_ROOT_UID
	int "User ID to map to 0 (user root)"
	depends on INITRAMFS_SOURCE!=""
	default "0"
	help
	  This setting is only meaningful if the INITRAMFS_SOURCE is
	  contains a directory.  Setting this user ID (UID) to something
	  other than "0" will cause all files owned by that UID to be
	  owned by user root in the initial ramdisk image.

	  If you are not sure, leave it set to "0".

config INITRAMFS_ROOT_GID
	int "Group ID to map to 0 (group root)"
	depends on INITRAMFS_SOURCE!=""
	default "0"
	help
	  This setting is only meaningful if the INITRAMFS_SOURCE is
	  contains a directory.  Setting this group ID (GID) to something
	  other than "0" will cause all files owned by that GID to be
	  owned by group root in the initial ramdisk image.

	  If you are not sure, leave it set to "0".
47 48

config RD_GZIP
49
	bool "Support initial ramdisks compressed using gzip" if EMBEDDED
50
	default y
51
	depends on BLK_DEV_INITRD
52 53 54 55 56 57
	select DECOMPRESS_GZIP
	help
	  Support loading of a gzip encoded initial ramdisk or cpio buffer.
	  If unsure, say Y.

config RD_BZIP2
58
	bool "Support initial ramdisks compressed using bzip2" if EMBEDDED
59 60
	default !EMBEDDED
	depends on BLK_DEV_INITRD
61 62 63 64 65 66
	select DECOMPRESS_BZIP2
	help
	  Support loading of a bzip2 encoded initial ramdisk or cpio buffer
	  If unsure, say N.

config RD_LZMA
67
	bool "Support initial ramdisks compressed using LZMA" if EMBEDDED
68 69
	default !EMBEDDED
	depends on BLK_DEV_INITRD
70 71
	select DECOMPRESS_LZMA
	help
72
	  Support loading of a LZMA encoded initial ramdisk or cpio buffer
73
	  If unsure, say N.
74

75 76
if INITRAMFS_SOURCE!=""

77 78 79
choice
	prompt "Built-in initramfs compression mode"
	help
80 81 82 83 84 85
	  This option decides by which algorithm the builtin initramfs
	  will be compressed.  Several compression algorithms are
	  available, which differ in efficiency, compression and
	  decompression speed.  Compression speed is only relevant
	  when building a kernel.  Decompression speed is relevant at
	  each boot.
86

87
	  If you have any problems with bzip2 or LZMA compressed
88 89
	  initramfs, mail me (Alain Knaff) <alain@knaff.lu>.

90 91 92
	  High compression options are mostly useful for users who are
	  low on RAM, since it reduces the memory consumption during
	  boot.
93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136

	  If in doubt, select 'gzip'

config INITRAMFS_COMPRESSION_NONE
	bool "None"
	help
	  Do not compress the built-in initramfs at all. This may
	  sound wasteful in space, but, you should be aware that the
	  built-in initramfs will be compressed at a later stage
	  anyways along with the rest of the kernel, on those
	  architectures that support this.
	  However, not compressing the initramfs may lead to slightly
	  higher memory consumption during a short time at boot, while
	  both the cpio image and the unpacked filesystem image will
	  be present in memory simultaneously

config INITRAMFS_COMPRESSION_GZIP
	bool "Gzip"
	depends on RD_GZIP
	help
	  The old and tried gzip compression. Its compression ratio is
	  the poorest among the 3 choices; however its speed (both
	  compression and decompression) is the fastest.

config INITRAMFS_COMPRESSION_BZIP2
	bool "Bzip2"
	depends on RD_BZIP2
	help
	  Its compression ratio and speed is intermediate.
	  Decompression speed is slowest among the three.  The initramfs
	  size is about 10% smaller with bzip2, in comparison to gzip.
	  Bzip2 uses a large amount of memory. For modern kernels you
	  will need at least 8MB RAM or more for booting.

config INITRAMFS_COMPRESSION_LZMA
	bool "LZMA"
	depends on RD_LZMA
	help
	  The most recent compression algorithm.
	  Its ratio is best, decompression speed is between the other
	  two. Compression is slowest.	The initramfs size is about 33%
	  smaller with LZMA in comparison to gzip.

endchoice
137 138 139 140 141 142 143 144 145 146 147

endif

if INITRAMFS_SOURCE=""
# The builtin initramfs is so small so we don't want to bug the user...

config INITRAMFS_COMPRESSION_NONE
	bool
	default y

endif