1 # SPDX-License-Identifier: GPL-2.0
2 #
3 # Configuration for initramfs
4 #
5
6 config INITRAMFS_SOURCE
7 string "Initramfs source file(s)"
8 default ""
9 help
10 This can be either a single cpio arc
11 space-separated list of directories
12 initramfs image. A cpio archive sho
13 to be used as an initramfs image. D
14 filesystem layout to be included in
15 should contain entries according to
16 "usr/gen_init_cpio" program in the k
17
18 When multiple directories and files
19 initramfs image will be the aggregat
20
21 See <file:Documentation/driver-api/e
22
23 If you are not sure, leave it blank.
24
25 config INITRAMFS_FORCE
26 bool "Ignore the initramfs passed by t
27 depends on CMDLINE_EXTEND || CMDLINE_F
28 help
29 This option causes the kernel to ign
30 (or initrd image) passed to it by th
31 analogous to CMDLINE_FORCE, which is
32 and is useful if you cannot or don't
33 your bootloader passes to the kernel
34
35 config INITRAMFS_ROOT_UID
36 int "User ID to map to 0 (user root)"
37 depends on INITRAMFS_SOURCE!=""
38 default "0"
39 help
40 If INITRAMFS_SOURCE points to a dire
41 (-1 = current user) will be owned by
42
43 If you are not sure, leave it set to
44
45 config INITRAMFS_ROOT_GID
46 int "Group ID to map to 0 (group root)
47 depends on INITRAMFS_SOURCE!=""
48 default "0"
49 help
50 If INITRAMFS_SOURCE points to a dire
51 (-1 = current group) will be owned b
52
53 If you are not sure, leave it set to
54
55 config RD_GZIP
56 bool "Support initial ramdisk/ramfs co
57 default y
58 select DECOMPRESS_GZIP
59 help
60 Support loading of a gzip encoded in
61 If unsure, say Y.
62
63 config RD_BZIP2
64 bool "Support initial ramdisk/ramfs co
65 default y
66 select DECOMPRESS_BZIP2
67 help
68 Support loading of a bzip2 encoded i
69 If unsure, say N.
70
71 config RD_LZMA
72 bool "Support initial ramdisk/ramfs co
73 default y
74 select DECOMPRESS_LZMA
75 help
76 Support loading of a LZMA encoded in
77 If unsure, say N.
78
79 config RD_XZ
80 bool "Support initial ramdisk/ramfs co
81 default y
82 select DECOMPRESS_XZ
83 help
84 Support loading of a XZ encoded init
85 If unsure, say N.
86
87 config RD_LZO
88 bool "Support initial ramdisk/ramfs co
89 default y
90 select DECOMPRESS_LZO
91 help
92 Support loading of a LZO encoded ini
93 If unsure, say N.
94
95 config RD_LZ4
96 bool "Support initial ramdisk/ramfs co
97 default y
98 select DECOMPRESS_LZ4
99 help
100 Support loading of a LZ4 encoded ini
101 If unsure, say N.
102
103 config RD_ZSTD
104 bool "Support initial ramdisk/ramfs co
105 default y
106 select DECOMPRESS_ZSTD
107 help
108 Support loading of a ZSTD encoded in
109 If unsure, say N.
110
111 choice
112 prompt "Built-in initramfs compression
113 depends on INITRAMFS_SOURCE != ""
114 help
115 This option allows you to decide by
116 initramfs will be compressed. Sever
117 available, which differ in efficienc
118 decompression speed. Compression sp
119 when building a kernel. Decompressi
120 each boot. Also the memory usage dur
121 relevant on memory constrained syste
122 dictionary size of the algorithm wit
123 featuring large dictionary sizes.
124
125 High compression options are mostly
126 low on RAM, since it reduces the mem
127 boot.
128
129 Keep in mind that your build system
130 compression tool to compress the gen
131 embedding.
132
133 If in doubt, select 'None'
134
135 config INITRAMFS_COMPRESSION_GZIP
136 bool "Gzip"
137 depends on RD_GZIP
138 help
139 Use the old and well tested gzip com
140 a good balance between compression r
141 has a reasonable compression speed.
142 supported by your build system as th
143 on most distros.
144
145 config INITRAMFS_COMPRESSION_BZIP2
146 bool "Bzip2"
147 depends on RD_BZIP2
148 help
149 It's compression ratio and speed is
150 is slowest among the choices. The in
151 with bzip2, in comparison to gzip. B
152 memory. For modern kernels you will
153 booting.
154
155 If you choose this, keep in mind tha
156 available to be able to compress the
157
158 config INITRAMFS_COMPRESSION_LZMA
159 bool "LZMA"
160 depends on RD_LZMA
161 help
162 This algorithm's compression ratio i
163 size which might cause issues in mem
164 Decompression speed is between the o
165 slowest. The initramfs size is about
166 comparison to gzip.
167
168 If you choose this, keep in mind tha
169 or lzma tools to be able to compress
170
171 config INITRAMFS_COMPRESSION_XZ
172 bool "XZ"
173 depends on RD_XZ
174 help
175 XZ uses the LZMA2 algorithm and has
176 problems on memory constrained syste
177 30% smaller with XZ in comparison to
178 better than that of bzip2 but worse
179 slow.
180
181 If you choose this, keep in mind tha
182 tool to be able to compress the init
183
184 config INITRAMFS_COMPRESSION_LZO
185 bool "LZO"
186 depends on RD_LZO
187 help
188 Its compression ratio is the second
189 kernel size is about 10% bigger than
190 decompression speed is the second fa
191 is quite fast too.
192
193 If you choose this, keep in mind tha
194 tool to be able to compress the init
195
196 config INITRAMFS_COMPRESSION_LZ4
197 bool "LZ4"
198 depends on RD_LZ4
199 help
200 It's compression ratio is the poores
201 size is about 15% bigger than gzip;
202 is the fastest.
203
204 If you choose this, keep in mind tha
205 by default which could cause a build
206
207 config INITRAMFS_COMPRESSION_ZSTD
208 bool "ZSTD"
209 depends on RD_ZSTD
210 help
211 ZSTD is a compression algorithm targ
212 with fast decompression speed. It wi
213 decompress around the same speed as
214
215 If you choose this, keep in mind tha
216 tool to be able to compress the init
217
218 config INITRAMFS_COMPRESSION_NONE
219 bool "None"
220 help
221 Do not compress the built-in initram
222 in space, but, you should be aware t
223 compressed at a later stage anyways
224 on those architectures that support
225 initramfs may lead to slightly highe
226 short time at boot, while both the c
227 filesystem image will be present in
228
229 endchoice
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