# # 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. config RD_LZ4 bool "Support initial ramdisks compressed using LZ4" if EXPERT default !EXPERT depends on BLK_DEV_INITRD select DECOMPRESS_LZ4 help Support loading of a LZ4 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 choices. 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 This algorithm's compression ratio is best. Decompression speed is between the other choices. 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 choices. The kernel size is about 10% bigger than gzip; however its speed (both compression and decompression) is the fastest. endchoice