| # |
| # 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 "Support initial ramdisks compressed using gzip" if EXPERT |
| 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 "Support initial ramdisks compressed using bzip2" if EXPERT |
| default !EXPERT |
| 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 "Support initial ramdisks compressed using LZMA" if EXPERT |
| default !EXPERT |
| depends on BLK_DEV_INITRD |
| select DECOMPRESS_LZMA |
| help |
| Support loading of a LZMA encoded initial ramdisk or cpio buffer |
| If unsure, say N. |
| |
| config RD_XZ |
| bool "Support initial ramdisks compressed using XZ" if EXPERT |
| default !EXPERT |
| depends on BLK_DEV_INITRD |
| select DECOMPRESS_XZ |
| help |
| Support loading of a XZ encoded initial ramdisk or cpio buffer. |
| If unsure, say N. |
| |
| config RD_LZO |
| bool "Support initial ramdisks compressed using LZO" if EXPERT |
| default !EXPERT |
| depends on BLK_DEV_INITRD |
| select DECOMPRESS_LZO |
| help |
| Support loading of a LZO encoded initial ramdisk or cpio buffer |
| If unsure, say N. |
| |
| choice |
| prompt "Built-in initramfs compression mode" if INITRAMFS_SOURCE!="" |
| help |
| This option decides by which algorithm the builtin initramfs |
| 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 RAM, since it reduces the memory consumption during |
| boot. |
| |
| 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. It provides a good balance |
| between compression ratio and decompression speed. |
| |
| config INITRAMFS_COMPRESSION_BZIP2 |
| bool "Bzip2" |
| depends on RD_BZIP2 |
| help |
| Its compression ratio and speed is intermediate. |
| Decompression speed is slowest among the four. 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 |
| three. Compression is slowest. The initramfs size is about 33% |
| smaller with LZMA in comparison to gzip. |
| |
| config INITRAMFS_COMPRESSION_XZ |
| bool "XZ" |
| depends on RD_XZ |
| help |
| XZ uses the LZMA2 algorithm. The initramfs size is about 30% |
| smaller with XZ in comparison to gzip. Decompression speed |
| is better than that of bzip2 but worse than gzip and LZO. |
| Compression is slow. |
| |
| config INITRAMFS_COMPRESSION_LZO |
| bool "LZO" |
| depends on RD_LZO |
| help |
| Its compression ratio is the poorest among the four. The kernel |
| size is about 10% bigger than gzip; however its speed |
| (both compression and decompression) is the fastest. |
| |
| endchoice |