| # |
| # 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. |
| |
| See <file:Documentation/early-userspace/README> for more details. |
| |
| 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". |
| |
| config RD_GZIP |
| bool "Initial ramdisk compressed using gzip" if EMBEDDED |
| default y |
| depends on BLK_DEV_INITRD |
| select DECOMPRESS_GZIP |
| help |
| Support loading of a gzip encoded initial ramdisk or cpio buffer. |
| If unsure, say Y. |
| |
| config RD_BZIP2 |
| bool "Initial ramdisk compressed using bzip2" if EMBEDDED |
| default !EMBEDDED |
| depends on BLK_DEV_INITRD |
| select DECOMPRESS_BZIP2 |
| help |
| Support loading of a bzip2 encoded initial ramdisk or cpio buffer |
| If unsure, say N. |
| |
| config RD_LZMA |
| bool "Initial ramdisk compressed using lzma" if EMBEDDED |
| default !EMBEDDED |
| depends on BLK_DEV_INITRD |
| select DECOMPRESS_LZMA |
| help |
| Support loading of a lzma encoded initial ramdisk or cpio buffer |
| If unsure, say N. |
| |
| choice |
| prompt "Built-in initramfs compression mode" |
| help |
| This setting is only meaningful if the INITRAMFS_SOURCE is |
| set. It decides by which algorithm the INITRAMFS_SOURCE 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. |
| |
| If you have any problems with bzip2 or lzma compressed |
| initramfs, mail me (Alain Knaff) <alain@knaff.lu>. |
| |
| High compression options are mostly useful for users who |
| are low on disk space (embedded systems), but for whom ram |
| size matters less. |
| |
| 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 |