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Sam Ravnborgdbec4862005-08-10 20:44:50 +02001#
2# Configuration for initramfs
3#
4
5config INITRAMFS_SOURCE
6 string "Initramfs source file(s)"
7 default ""
8 help
9 This can be either a single cpio archive with a .cpio suffix or a
10 space-separated list of directories and files for building the
11 initramfs image. A cpio archive should contain a filesystem archive
12 to be used as an initramfs image. Directories should contain a
13 filesystem layout to be included in the initramfs image. Files
14 should contain entries according to the format described by the
15 "usr/gen_init_cpio" program in the kernel tree.
16
17 When multiple directories and files are specified then the
18 initramfs image will be the aggregate of all of them.
19
Alexander E. Patrakov0979f372007-03-16 18:01:45 +050020 See <file:Documentation/early-userspace/README> for more details.
Sam Ravnborgdbec4862005-08-10 20:44:50 +020021
22 If you are not sure, leave it blank.
23
24config INITRAMFS_ROOT_UID
25 int "User ID to map to 0 (user root)"
26 depends on INITRAMFS_SOURCE!=""
27 default "0"
28 help
29 This setting is only meaningful if the INITRAMFS_SOURCE is
30 contains a directory. Setting this user ID (UID) to something
31 other than "0" will cause all files owned by that UID to be
32 owned by user root in the initial ramdisk image.
33
34 If you are not sure, leave it set to "0".
35
36config INITRAMFS_ROOT_GID
37 int "Group ID to map to 0 (group root)"
38 depends on INITRAMFS_SOURCE!=""
39 default "0"
40 help
41 This setting is only meaningful if the INITRAMFS_SOURCE is
42 contains a directory. Setting this group ID (GID) to something
43 other than "0" will cause all files owned by that GID to be
44 owned by group root in the initial ramdisk image.
45
46 If you are not sure, leave it set to "0".
H. Peter Anvinfb9a4ca2009-01-07 00:03:49 -080047
48config RD_GZIP
Andi Kleenec72c662014-12-12 16:58:03 -080049 bool "Support initial ramdisks compressed using gzip"
H. Peter Anvin73d8a122009-03-28 15:49:08 -070050 depends on BLK_DEV_INITRD
Andi Kleenec72c662014-12-12 16:58:03 -080051 default y
H. Peter Anvinfb9a4ca2009-01-07 00:03:49 -080052 select DECOMPRESS_GZIP
53 help
54 Support loading of a gzip encoded initial ramdisk or cpio buffer.
55 If unsure, say Y.
56
57config RD_BZIP2
Andi Kleenec72c662014-12-12 16:58:03 -080058 bool "Support initial ramdisks compressed using bzip2"
59 default y
H. Peter Anvin73d8a122009-03-28 15:49:08 -070060 depends on BLK_DEV_INITRD
H. Peter Anvinfb9a4ca2009-01-07 00:03:49 -080061 select DECOMPRESS_BZIP2
62 help
63 Support loading of a bzip2 encoded initial ramdisk or cpio buffer
64 If unsure, say N.
65
66config RD_LZMA
Andi Kleenec72c662014-12-12 16:58:03 -080067 bool "Support initial ramdisks compressed using LZMA"
68 default y
H. Peter Anvin73d8a122009-03-28 15:49:08 -070069 depends on BLK_DEV_INITRD
H. Peter Anvinfb9a4ca2009-01-07 00:03:49 -080070 select DECOMPRESS_LZMA
71 help
H. Peter Anvin55d1d262009-03-28 16:10:59 -070072 Support loading of a LZMA encoded initial ramdisk or cpio buffer
H. Peter Anvinfb9a4ca2009-01-07 00:03:49 -080073 If unsure, say N.
Alain Knaffab76f3d2009-02-19 13:43:51 -080074
Lasse Collin3ebe1242011-01-12 17:01:23 -080075config RD_XZ
Andi Kleenec72c662014-12-12 16:58:03 -080076 bool "Support initial ramdisks compressed using XZ"
Lasse Collin3ebe1242011-01-12 17:01:23 -080077 depends on BLK_DEV_INITRD
Andi Kleenec72c662014-12-12 16:58:03 -080078 default y
Lasse Collin3ebe1242011-01-12 17:01:23 -080079 select DECOMPRESS_XZ
80 help
81 Support loading of a XZ encoded initial ramdisk or cpio buffer.
82 If unsure, say N.
83
Albin Tonnerrecacb2462010-01-08 14:42:46 -080084config RD_LZO
Andi Kleenec72c662014-12-12 16:58:03 -080085 bool "Support initial ramdisks compressed using LZO"
86 default y
Albin Tonnerrecacb2462010-01-08 14:42:46 -080087 depends on BLK_DEV_INITRD
88 select DECOMPRESS_LZO
89 help
90 Support loading of a LZO encoded initial ramdisk or cpio buffer
91 If unsure, say N.
92
Kyungsik Leee76e1fd2013-07-08 16:01:46 -070093config RD_LZ4
Andi Kleenec72c662014-12-12 16:58:03 -080094 bool "Support initial ramdisks compressed using LZ4"
95 default y
Kyungsik Leee76e1fd2013-07-08 16:01:46 -070096 depends on BLK_DEV_INITRD
97 select DECOMPRESS_LZ4
98 help
99 Support loading of a LZ4 encoded initial ramdisk or cpio buffer
100 If unsure, say N.
Francisco Blas Izquierdo Riera (klondike)35e669e2016-12-14 15:06:01 -0800101
Francisco Blas Izquierdo Riera (klondike)db2aa7f2016-12-14 15:06:04 -0800102choice
103 prompt "Built-in initramfs compression mode"
104 depends on INITRAMFS_SOURCE!=""
105 optional
106 help
107 This option allows you to decide by which algorithm the builtin
108 initramfs will be compressed. Several compression algorithms are
109 available, which differ in efficiency, compression and
110 decompression speed. Compression speed is only relevant
111 when building a kernel. Decompression speed is relevant at
112 each boot. Also the memory usage during decompression may become
113 relevant on memory constrained systems. This is usually based on the
114 dictionary size of the algorithm with algorithms like XZ and LZMA
115 featuring large dictionary sizes.
116
117 High compression options are mostly useful for users who are
118 low on RAM, since it reduces the memory consumption during
119 boot.
120
121 Keep in mind that your build system needs to provide the appropriate
122 compression tool to compress the generated initram cpio file for
123 embedding.
124
125 If in doubt, select 'None'
126
127config INITRAMFS_COMPRESSION_NONE
128 bool "None"
129 help
130 Do not compress the built-in initramfs at all. This may sound wasteful
131 in space, but, you should be aware that the built-in initramfs will be
132 compressed at a later stage anyways along with the rest of the kernel,
133 on those architectures that support this. However, not compressing the
134 initramfs may lead to slightly higher memory consumption during a
135 short time at boot, while both the cpio image and the unpacked
136 filesystem image will be present in memory simultaneously
137
138config INITRAMFS_COMPRESSION_GZIP
139 bool "Gzip"
140 depends on RD_GZIP
141 help
142 Use the old and well tested gzip compression algorithm. Gzip provides
143 a good balance between compression ratio and decompression speed and
144 has a reasonable compression speed. It is also more likely to be
145 supported by your build system as the gzip tool is present by default
146 on most distros.
147
148config INITRAMFS_COMPRESSION_BZIP2
149 bool "Bzip2"
150 depends on RD_BZIP2
151 help
152 It's compression ratio and speed is intermediate. Decompression speed
153 is slowest among the choices. The initramfs size is about 10% smaller
154 with bzip2, in comparison to gzip. Bzip2 uses a large amount of
155 memory. For modern kernels you will need at least 8MB RAM or more for
156 booting.
157
158 If you choose this, keep in mind that you need to have the bzip2 tool
159 available to be able to compress the initram.
160
161config INITRAMFS_COMPRESSION_LZMA
162 bool "LZMA"
163 depends on RD_LZMA
164 help
165 This algorithm's compression ratio is best but has a large dictionary
166 size which might cause issues in memory constrained systems.
167 Decompression speed is between the other choices. Compression is
168 slowest. The initramfs size is about 33% smaller with LZMA in
169 comparison to gzip.
170
171 If you choose this, keep in mind that you may need to install the xz
172 or lzma tools to be able to compress the initram.
173
174config INITRAMFS_COMPRESSION_XZ
175 bool "XZ"
176 depends on RD_XZ
177 help
178 XZ uses the LZMA2 algorithm and has a large dictionary which may cause
179 problems on memory constrained systems. The initramfs size is about
180 30% smaller with XZ in comparison to gzip. Decompression speed is
181 better than that of bzip2 but worse than gzip and LZO. Compression is
182 slow.
183
184 If you choose this, keep in mind that you may need to install the xz
185 tool to be able to compress the initram.
186
187config INITRAMFS_COMPRESSION_LZO
188 bool "LZO"
189 depends on RD_LZO
190 help
191 It's compression ratio is the second poorest amongst the choices. The
192 kernel size is about 10% bigger than gzip. Despite that, it's
193 decompression speed is the second fastest and it's compression speed
194 is quite fast too.
195
196 If you choose this, keep in mind that you may need to install the lzop
197 tool to be able to compress the initram.
198
199config INITRAMFS_COMPRESSION_LZ4
200 bool "LZ4"
201 depends on RD_LZ4
202 help
203 It's compression ratio is the poorest amongst the choices. The kernel
204 size is about 15% bigger than gzip; however its decompression speed
205 is the fastest.
206
207 If you choose this, keep in mind that most distros don't provide lz4
208 by default which could cause a build failure.
209
210endchoice
211
Francisco Blas Izquierdo Riera (klondike)35e669e2016-12-14 15:06:01 -0800212config INITRAMFS_COMPRESSION
213 string
Francisco Blas Izquierdo Riera (klondike)db2aa7f2016-12-14 15:06:04 -0800214 default "" if INITRAMFS_COMPRESSION_NONE
215 default ".gz" if INITRAMFS_COMPRESSION_GZIP
216 default ".bz2" if INITRAMFS_COMPRESSION_BZIP2
217 default ".lzma" if INITRAMFS_COMPRESSION_LZMA
218 default ".xz" if INITRAMFS_COMPRESSION_XZ
219 default ".lzo" if INITRAMFS_COMPRESSION_LZO
220 default ".lz4" if INITRAMFS_COMPRESSION_LZ4
Francisco Blas Izquierdo Riera (klondike)35e669e2016-12-14 15:06:01 -0800221 default ".gz" if RD_GZIP
222 default ".lz4" if RD_LZ4
223 default ".lzo" if RD_LZO
224 default ".xz" if RD_XZ
225 default ".lzma" if RD_LZMA
226 default ".bz2" if RD_BZIP2
227 default ""