1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 config ROMFS_FS 2 config ROMFS_FS
3 tristate "ROM file system support" 3 tristate "ROM file system support"
4 depends on BLOCK || MTD 4 depends on BLOCK || MTD
5 help 5 help
6 This is a very small read-only file 6 This is a very small read-only file system mainly intended for
7 initial ram disks of installation di 7 initial ram disks of installation disks, but it could be used for
8 other read-only media as well. Read 8 other read-only media as well. Read
9 <file:Documentation/filesystems/romf 9 <file:Documentation/filesystems/romfs.rst> for details.
10 10
11 To compile this file system support 11 To compile this file system support as a module, choose M here: the
12 module will be called romfs. Note t 12 module will be called romfs. Note that the file system of your
13 root partition (the one containing t 13 root partition (the one containing the directory /) cannot be a
14 module. 14 module.
15 15
16 If you don't know whether you need i 16 If you don't know whether you need it, then you don't need it:
17 answer N. 17 answer N.
18 18
19 # 19 #
20 # Select the backing stores to be supported 20 # Select the backing stores to be supported
21 # 21 #
22 choice 22 choice
23 prompt "RomFS backing stores" 23 prompt "RomFS backing stores"
24 depends on ROMFS_FS 24 depends on ROMFS_FS
25 default ROMFS_BACKED_BY_BLOCK 25 default ROMFS_BACKED_BY_BLOCK
26 help 26 help
27 Select the backing stores to be supp 27 Select the backing stores to be supported.
28 28
29 config ROMFS_BACKED_BY_BLOCK 29 config ROMFS_BACKED_BY_BLOCK
30 bool "Block device-backed ROM file sys 30 bool "Block device-backed ROM file system support"
31 depends on BLOCK 31 depends on BLOCK
32 help 32 help
33 This permits ROMFS to use block devi 33 This permits ROMFS to use block devices buffered through the page
34 cache as the medium from which to re 34 cache as the medium from which to retrieve data. It does not allow
35 direct mapping of the medium. 35 direct mapping of the medium.
36 36
37 If unsure, answer Y. 37 If unsure, answer Y.
38 38
39 config ROMFS_BACKED_BY_MTD 39 config ROMFS_BACKED_BY_MTD
40 bool "MTD-backed ROM file system suppo 40 bool "MTD-backed ROM file system support"
41 depends on MTD=y || (ROMFS_FS=m && MTD 41 depends on MTD=y || (ROMFS_FS=m && MTD)
42 help 42 help
43 This permits ROMFS to use MTD based 43 This permits ROMFS to use MTD based devices directly, without the
44 intercession of the block layer (whi 44 intercession of the block layer (which may have been disabled). It
45 also allows direct mapping of MTD de 45 also allows direct mapping of MTD devices through romfs files under
46 NOMMU conditions if the underlying d 46 NOMMU conditions if the underlying device is directly addressable by
47 the CPU. 47 the CPU.
48 48
49 If unsure, answer Y. 49 If unsure, answer Y.
50 50
51 config ROMFS_BACKED_BY_BOTH 51 config ROMFS_BACKED_BY_BOTH
52 bool "Both the above" 52 bool "Both the above"
53 depends on BLOCK && (MTD=y || (ROMFS_F 53 depends on BLOCK && (MTD=y || (ROMFS_FS=m && MTD))
54 endchoice 54 endchoice
55 55
56 56
57 config ROMFS_ON_BLOCK 57 config ROMFS_ON_BLOCK
58 bool 58 bool
59 default y if ROMFS_BACKED_BY_BLOCK || 59 default y if ROMFS_BACKED_BY_BLOCK || ROMFS_BACKED_BY_BOTH
60 select BUFFER_HEAD 60 select BUFFER_HEAD
61 61
62 config ROMFS_ON_MTD 62 config ROMFS_ON_MTD
63 bool 63 bool
64 default y if ROMFS_BACKED_BY_MTD || RO 64 default y if ROMFS_BACKED_BY_MTD || ROMFS_BACKED_BY_BOTH
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