If you are not sure, leave it set to "0".
config RD_GZIP
- bool "Initial ramdisk compressed using gzip" if EMBEDDED
+ bool "Support initial ramdisks compressed using gzip" if EMBEDDED
default y
depends on BLK_DEV_INITRD
select DECOMPRESS_GZIP
If unsure, say Y.
config RD_BZIP2
- bool "Initial ramdisk compressed using bzip2" if EMBEDDED
+ bool "Support initial ramdisks compressed using bzip2" if EMBEDDED
default !EMBEDDED
depends on BLK_DEV_INITRD
select DECOMPRESS_BZIP2
If unsure, say N.
config RD_LZMA
- bool "Initial ramdisk compressed using lzma" if EMBEDDED
+ bool "Support initial ramdisks 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
+ Support loading of a LZMA encoded initial ramdisk or cpio buffer
+ If unsure, say N.
+
+config RD_LZO
+ bool "Support initial ramdisks compressed using LZO" if EMBEDDED
+ default !EMBEDDED
+ 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"
+ prompt "Built-in initramfs compression mode" if INITRAMFS_SOURCE!=""
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
+ 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 disk space (embedded systems), but for whom ram
- size matters less.
+ 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'
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.
+ 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 three. The initramfs
+ 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.
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%
+ three. Compression is slowest. The initramfs size is about 33%
smaller with LZMA in comparison to gzip.
+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 about 10% bigger than gzip; however its speed
+ (both compression and decompression) is the fastest.
+
endchoice