projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blame
| Commit | Line | Data |
|---|---|---|
| dbec4866 SR |
1 | # |
| 2 | # Configuration for initramfs | |
| 3 | # | |
| 4 | ||
| 5 | config 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 | ||
| 0979f378 | 20 | See <file:Documentation/early-userspace/README> for more details. |
| dbec4866 SR |
21 | |
| 22 | If you are not sure, leave it blank. | |
| 23 | ||
| 24 | config 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 | ||
| 36 | config 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". | |
| fb9a4ca9 PA |
47 | |
| 48 | config RD_GZIP | |
| 49 | bool "Initial ramdisk compressed using gzip" | |
| 50 | default y | |
| 51 | depends on BLK_DEV_INITRD=y | |
| 52 | select DECOMPRESS_GZIP | |
| 53 | help | |
| 54 | Support loading of a gzip encoded initial ramdisk or cpio buffer. | |
| 55 | If unsure, say Y. | |
| 56 | ||
| 57 | config RD_BZIP2 | |
| 58 | bool "Initial ramdisk compressed using bzip2" | |
| 59 | default n | |
| 60 | depends on BLK_DEV_INITRD=y | |
| 61 | select DECOMPRESS_BZIP2 | |
| 62 | help | |
| 63 | Support loading of a bzip2 encoded initial ramdisk or cpio buffer | |
| 64 | If unsure, say N. | |
| 65 | ||
| 66 | config RD_LZMA | |
| 67 | bool "Initial ramdisk compressed using lzma" | |
| 68 | default n | |
| 69 | depends on BLK_DEV_INITRD=y | |
| 70 | select DECOMPRESS_LZMA | |
| 71 | help | |
| 72 | Support loading of a lzma encoded initial ramdisk or cpio buffer | |
| 73 | If unsure, say N. | |
| ab76f3d7 AK |
74 | |
| 75 | choice | |
| 76 | prompt "Built-in initramfs compression mode" | |
| 77 | help | |
| 78 | This setting is only meaningful if the INITRAMFS_SOURCE is | |
| 79 | set. It decides by which algorithm the INITRAMFS_SOURCE will | |
| 80 | be compressed. | |
| 81 | Several compression algorithms are available, which differ | |
| 82 | in efficiency, compression and decompression speed. | |
| 83 | Compression speed is only relevant when building a kernel. | |
| 84 | Decompression speed is relevant at each boot. | |
| 85 | ||
| 86 | If you have any problems with bzip2 or lzma compressed | |
| 87 | initramfs, mail me (Alain Knaff) <alain@knaff.lu>. | |
| 88 | ||
| 89 | High compression options are mostly useful for users who | |
| 90 | are low on disk space (embedded systems), but for whom ram | |
| 91 | size matters less. | |
| 92 | ||
| 93 | If in doubt, select 'gzip' | |
| 94 | ||
| 95 | config INITRAMFS_COMPRESSION_NONE | |
| 96 | bool "None" | |
| 97 | help | |
| 98 | Do not compress the built-in initramfs at all. This may | |
| 99 | sound wasteful in space, but, you should be aware that the | |
| 100 | built-in initramfs will be compressed at a later stage | |
| 101 | anyways along with the rest of the kernel, on those | |
| 102 | architectures that support this. | |
| 103 | However, not compressing the initramfs may lead to slightly | |
| 104 | higher memory consumption during a short time at boot, while | |
| 105 | both the cpio image and the unpacked filesystem image will | |
| 106 | be present in memory simultaneously | |
| 107 | ||
| 108 | config INITRAMFS_COMPRESSION_GZIP | |
| 109 | bool "Gzip" | |
| 110 | depends on RD_GZIP | |
| 111 | help | |
| 112 | The old and tried gzip compression. Its compression ratio is | |
| 113 | the poorest among the 3 choices; however its speed (both | |
| 114 | compression and decompression) is the fastest. | |
| 115 | ||
| 116 | config INITRAMFS_COMPRESSION_BZIP2 | |
| 117 | bool "Bzip2" | |
| 118 | depends on RD_BZIP2 | |
| 119 | help | |
| 120 | Its compression ratio and speed is intermediate. | |
| 121 | Decompression speed is slowest among the three. The initramfs | |
| 122 | size is about 10% smaller with bzip2, in comparison to gzip. | |
| 123 | Bzip2 uses a large amount of memory. For modern kernels you | |
| 124 | will need at least 8MB RAM or more for booting. | |
| 125 | ||
| 126 | config INITRAMFS_COMPRESSION_LZMA | |
| 127 | bool "LZMA" | |
| 128 | depends on RD_LZMA | |
| 129 | help | |
| 130 | The most recent compression algorithm. | |
| 131 | Its ratio is best, decompression speed is between the other | |
| 132 | two. Compression is slowest. The initramfs size is about 33% | |
| 133 | smaller with LZMA in comparison to gzip. | |
| 134 | ||
| 135 | endchoice |