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authorAlain Knaff <alain@knaff.lu>2009-01-04 16:46:17 -0500
committerH. Peter Anvin <hpa@zytor.com>2009-01-04 18:53:35 -0500
commit30d65dbfe3add7f010a075991dc0bfeaebb7d9e1 (patch)
treec60ce6748eea43d1e74d96ef03990b1e23f33b1d /init/Kconfig
parentbc22c17e12c130dc929218a95aa347e0f3fd05dc (diff)
bzip2/lzma: config and initramfs support for bzip2/lzma decompression
Impact: New code for initramfs decompression, new features This is the second part of the bzip2/lzma patch The bzip patch is based on an idea by Christian Ludwig, includes support for compressing the kernel with bzip2 or lzma rather than gzip. Both compressors give smaller sizes than gzip. Lzma's decompresses faster than bzip2. It also supports ramdisks and initramfs' compressed using these two compressors. The functionality has been successfully used for a couple of years by the udpcast project This version applies to "tip" kernel 2.6.28 This part contains: - support for new compressions (bzip2 and lzma) in initramfs and old-style ramdisk - config dialog for kernel compression (but new kernel compressions not yet supported) Signed-off-by: Alain Knaff <alain@knaff.lu> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'init/Kconfig')
-rw-r--r--init/Kconfig50
1 files changed, 50 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig
index f6281711166d..df84625b1373 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -101,6 +101,56 @@ config LOCALVERSION_AUTO
101 101
102 which is done within the script "scripts/setlocalversion".) 102 which is done within the script "scripts/setlocalversion".)
103 103
104choice
105 prompt "Kernel compression mode"
106 default KERNEL_GZIP
107 help
108 The linux kernel is a kind of self-extracting executable.
109 Several compression algorithms are available, which differ
110 in efficiency, compression and decompression speed.
111 Compression speed is only relevant when building a kernel.
112 Decompression speed is relevant at each boot.
113
114 If you have any problems with bzip2 or lzma compressed
115 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
116 version of this functionality (bzip2 only), for 2.4, was
117 supplied by Christian Ludwig)
118
119 High compression options are mostly useful for users, who
120 are low on disk space (embedded systems), but for whom ram
121 size matters less.
122
123 If in doubt, select 'gzip'
124
125config KERNEL_GZIP
126 bool "Gzip"
127 help
128 The old and tried gzip compression. Its compression ratio is
129 the poorest among the 3 choices; however its speed (both
130 compression and decompression) is the fastest.
131
132config KERNEL_BZIP2
133 bool "Bzip2"
134 help
135 Its compression ratio and speed is intermediate.
136 Decompression speed is slowest among the 3.
137 The kernel size is about 10 per cent smaller with bzip2,
138 in comparison to gzip.
139 Bzip2 uses a large amount of memory. For modern kernels
140 you will need at least 8MB RAM or more for booting.
141
142config KERNEL_LZMA
143 bool "LZMA"
144 help
145 The most recent compression algorithm.
146 Its ratio is best, decompression speed is between the other
147 2. Compression is slowest.
148 The kernel size is about 33 per cent smaller with lzma,
149 in comparison to gzip.
150
151endchoice
152
153
104config SWAP 154config SWAP
105 bool "Support for paging of anonymous memory (swap)" 155 bool "Support for paging of anonymous memory (swap)"
106 depends on MMU && BLOCK 156 depends on MMU && BLOCK