55d1d26f23
Impact: message formatting Consistently spell LZMA in all capitals, since it (unlike gzip or bzip2) is an acronym. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
136 lines
4.4 KiB
Plaintext
136 lines
4.4 KiB
Plaintext
#
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# Configuration for initramfs
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#
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config INITRAMFS_SOURCE
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string "Initramfs source file(s)"
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default ""
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help
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This can be either a single cpio archive with a .cpio suffix or a
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space-separated list of directories and files for building the
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initramfs image. A cpio archive should contain a filesystem archive
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to be used as an initramfs image. Directories should contain a
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filesystem layout to be included in the initramfs image. Files
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should contain entries according to the format described by the
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"usr/gen_init_cpio" program in the kernel tree.
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When multiple directories and files are specified then the
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initramfs image will be the aggregate of all of them.
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See <file:Documentation/early-userspace/README> for more details.
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If you are not sure, leave it blank.
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config INITRAMFS_ROOT_UID
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int "User ID to map to 0 (user root)"
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depends on INITRAMFS_SOURCE!=""
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default "0"
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help
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This setting is only meaningful if the INITRAMFS_SOURCE is
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contains a directory. Setting this user ID (UID) to something
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other than "0" will cause all files owned by that UID to be
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owned by user root in the initial ramdisk image.
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If you are not sure, leave it set to "0".
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config INITRAMFS_ROOT_GID
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int "Group ID to map to 0 (group root)"
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depends on INITRAMFS_SOURCE!=""
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default "0"
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help
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This setting is only meaningful if the INITRAMFS_SOURCE is
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contains a directory. Setting this group ID (GID) to something
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other than "0" will cause all files owned by that GID to be
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owned by group root in the initial ramdisk image.
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If you are not sure, leave it set to "0".
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config RD_GZIP
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bool "Support initial ramdisks compressed using gzip" if EMBEDDED
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default y
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depends on BLK_DEV_INITRD
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select DECOMPRESS_GZIP
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help
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Support loading of a gzip encoded initial ramdisk or cpio buffer.
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If unsure, say Y.
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config RD_BZIP2
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bool "Support initial ramdisks compressed using bzip2" if EMBEDDED
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default !EMBEDDED
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depends on BLK_DEV_INITRD
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select DECOMPRESS_BZIP2
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help
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Support loading of a bzip2 encoded initial ramdisk or cpio buffer
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If unsure, say N.
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config RD_LZMA
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bool "Support initial ramdisks compressed using LZMA" if EMBEDDED
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default !EMBEDDED
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depends on BLK_DEV_INITRD
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select DECOMPRESS_LZMA
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help
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Support loading of a LZMA encoded initial ramdisk or cpio buffer
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If unsure, say N.
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choice
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prompt "Built-in initramfs compression mode"
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help
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This setting is only meaningful if the INITRAMFS_SOURCE is
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set. It decides by which algorithm the INITRAMFS_SOURCE will
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be compressed.
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Several compression algorithms are available, which differ
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in efficiency, compression and decompression speed.
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Compression speed is only relevant when building a kernel.
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Decompression speed is relevant at each boot.
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If you have any problems with bzip2 or LZMA compressed
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initramfs, mail me (Alain Knaff) <alain@knaff.lu>.
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High compression options are mostly useful for users who
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are low on disk space (embedded systems), but for whom ram
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size matters less.
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If in doubt, select 'gzip'
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config INITRAMFS_COMPRESSION_NONE
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bool "None"
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help
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Do not compress the built-in initramfs at all. This may
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sound wasteful in space, but, you should be aware that the
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built-in initramfs will be compressed at a later stage
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anyways along with the rest of the kernel, on those
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architectures that support this.
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However, not compressing the initramfs may lead to slightly
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higher memory consumption during a short time at boot, while
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both the cpio image and the unpacked filesystem image will
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be present in memory simultaneously
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config INITRAMFS_COMPRESSION_GZIP
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bool "Gzip"
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depends on RD_GZIP
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help
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The old and tried gzip compression. Its compression ratio is
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the poorest among the 3 choices; however its speed (both
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compression and decompression) is the fastest.
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config INITRAMFS_COMPRESSION_BZIP2
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bool "Bzip2"
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depends on RD_BZIP2
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help
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Its compression ratio and speed is intermediate.
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Decompression speed is slowest among the three. The initramfs
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size is about 10% smaller with bzip2, in comparison to gzip.
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Bzip2 uses a large amount of memory. For modern kernels you
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will need at least 8MB RAM or more for booting.
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config INITRAMFS_COMPRESSION_LZMA
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bool "LZMA"
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depends on RD_LZMA
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help
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The most recent compression algorithm.
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Its ratio is best, decompression speed is between the other
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two. Compression is slowest. The initramfs size is about 33%
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smaller with LZMA in comparison to gzip.
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endchoice
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