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authorAlbin Tonnerre <albin.tonnerre@free-electrons.com>2010-01-08 17:42:42 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2010-01-11 12:34:04 -0500
commit7dd65feb6c603e13eba501c34c662259ab38e70e (patch)
tree5ec4bf4ab09310dce796fc7a2067c18d76b4aa75
parentac4c2a3bbe5db5fc570b1d0ee1e474db7cb22585 (diff)
lib: add support for LZO-compressed kernels
This patch series adds generic support for creating and extracting LZO-compressed kernel images, as well as support for using such images on the x86 and ARM architectures, and support for creating and using LZO-compressed initrd and initramfs images. Russell King said: : Testing on a Cortex A9 model: : - lzo decompressor is 65% of the time gzip takes to decompress a kernel : - lzo kernel is 9% larger than a gzip kernel : : which I'm happy to say confirms your figures when comparing the two. : : However, when comparing your new gzip code to the old gzip code: : - new is 99% of the size of the old code : - new takes 42% of the time to decompress than the old code : : What this means is that for a proper comparison, the results get even better: : - lzo is 7.5% larger than the old gzip'd kernel image : - lzo takes 28% of the time that the old gzip code took : : So the expense seems definitely worth the effort. The only reason I : can think of ever using gzip would be if you needed the additional : compression (eg, because you have limited flash to store the image.) : : I would argue that the default for ARM should therefore be LZO. This patch: The lzo compressor is worse than gzip at compression, but faster at extraction. Here are some figures for an ARM board I'm working on: Uncompressed size: 3.24Mo gzip 1.61Mo 0.72s lzo 1.75Mo 0.48s So for a compression ratio that is still relatively close to gzip, it's much faster to extract, at least in that case. This part contains: - Makefile routine to support lzo compression - Fixes to the existing lzo compressor so that it can be used in compressed kernels - wrapper around the existing lzo1x_decompress, as it only extracts one block at a time, while we need to extract a whole file here - config dialog for kernel compression [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: cleanup] Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com> Tested-by: Wu Zhangjin <wuzhangjin@gmail.com> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Tested-by: Russell King <rmk@arm.linux.org.uk> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/decompress/unlzo.h10
-rw-r--r--init/Kconfig18
-rw-r--r--lib/decompress_unlzo.c209
-rw-r--r--lib/lzo/lzo1x_decompress.c9
-rw-r--r--scripts/Makefile.lib5
5 files changed, 244 insertions, 7 deletions
diff --git a/include/linux/decompress/unlzo.h b/include/linux/decompress/unlzo.h
new file mode 100644
index 000000000000..987229752519
--- /dev/null
+++ b/include/linux/decompress/unlzo.h
@@ -0,0 +1,10 @@
1#ifndef DECOMPRESS_UNLZO_H
2#define DECOMPRESS_UNLZO_H
3
4int unlzo(unsigned char *inbuf, int len,
5 int(*fill)(void*, unsigned int),
6 int(*flush)(void*, unsigned int),
7 unsigned char *output,
8 int *pos,
9 void(*error)(char *x));
10#endif
diff --git a/init/Kconfig b/init/Kconfig
index a23da9f01803..d95ca7cd5d45 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -115,10 +115,13 @@ config HAVE_KERNEL_BZIP2
115config HAVE_KERNEL_LZMA 115config HAVE_KERNEL_LZMA
116 bool 116 bool
117 117
118config HAVE_KERNEL_LZO
119 bool
120
118choice 121choice
119 prompt "Kernel compression mode" 122 prompt "Kernel compression mode"
120 default KERNEL_GZIP 123 default KERNEL_GZIP
121 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA 124 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_LZO
122 help 125 help
123 The linux kernel is a kind of self-extracting executable. 126 The linux kernel is a kind of self-extracting executable.
124 Several compression algorithms are available, which differ 127 Several compression algorithms are available, which differ
@@ -141,9 +144,8 @@ config KERNEL_GZIP
141 bool "Gzip" 144 bool "Gzip"
142 depends on HAVE_KERNEL_GZIP 145 depends on HAVE_KERNEL_GZIP
143 help 146 help
144 The old and tried gzip compression. Its compression ratio is 147 The old and tried gzip compression. It provides a good balance
145 the poorest among the 3 choices; however its speed (both 148 between compression ratio and decompression speed.
146 compression and decompression) is the fastest.
147 149
148config KERNEL_BZIP2 150config KERNEL_BZIP2
149 bool "Bzip2" 151 bool "Bzip2"
@@ -164,6 +166,14 @@ config KERNEL_LZMA
164 two. Compression is slowest. The kernel size is about 33% 166 two. Compression is slowest. The kernel size is about 33%
165 smaller with LZMA in comparison to gzip. 167 smaller with LZMA in comparison to gzip.
166 168
169config KERNEL_LZO
170 bool "LZO"
171 depends on HAVE_KERNEL_LZO
172 help
173 Its compression ratio is the poorest among the 4. The kernel
174 size is about about 10% bigger than gzip; however its speed
175 (both compression and decompression) is the fastest.
176
167endchoice 177endchoice
168 178
169config SWAP 179config SWAP
diff --git a/lib/decompress_unlzo.c b/lib/decompress_unlzo.c
new file mode 100644
index 000000000000..db521f45626e
--- /dev/null
+++ b/lib/decompress_unlzo.c
@@ -0,0 +1,209 @@
1/*
2 * LZO decompressor for the Linux kernel. Code borrowed from the lzo
3 * implementation by Markus Franz Xaver Johannes Oberhumer.
4 *
5 * Linux kernel adaptation:
6 * Copyright (C) 2009
7 * Albin Tonnerre, Free Electrons <albin.tonnerre@free-electrons.com>
8 *
9 * Original code:
10 * Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
11 * All Rights Reserved.
12 *
13 * lzop and the LZO library are free software; you can redistribute them
14 * and/or modify them under the terms of the GNU General Public License as
15 * published by the Free Software Foundation; either version 2 of
16 * the License, or (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; see the file COPYING.
25 * If not, write to the Free Software Foundation, Inc.,
26 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 *
28 * Markus F.X.J. Oberhumer
29 * <markus@oberhumer.com>
30 * http://www.oberhumer.com/opensource/lzop/
31 */
32
33#ifdef STATIC
34#include "lzo/lzo1x_decompress.c"
35#else
36#include <linux/slab.h>
37#include <linux/decompress/unlzo.h>
38#endif
39
40#include <linux/types.h>
41#include <linux/lzo.h>
42#include <linux/decompress/mm.h>
43
44#include <linux/compiler.h>
45#include <asm/unaligned.h>
46
47static const unsigned char lzop_magic[] = {
48 0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a };
49
50#define LZO_BLOCK_SIZE (256*1024l)
51#define HEADER_HAS_FILTER 0x00000800L
52
53STATIC inline int INIT parse_header(u8 *input, u8 *skip)
54{
55 int l;
56 u8 *parse = input;
57 u8 level = 0;
58 u16 version;
59
60 /* read magic: 9 first bits */
61 for (l = 0; l < 9; l++) {
62 if (*parse++ != lzop_magic[l])
63 return 0;
64 }
65 /* get version (2bytes), skip library version (2),
66 * 'need to be extracted' version (2) and
67 * method (1) */
68 version = get_unaligned_be16(parse);
69 parse += 7;
70 if (version >= 0x0940)
71 level = *parse++;
72 if (get_unaligned_be32(parse) & HEADER_HAS_FILTER)
73 parse += 8; /* flags + filter info */
74 else
75 parse += 4; /* flags */
76
77 /* skip mode and mtime_low */
78 parse += 8;
79 if (version >= 0x0940)
80 parse += 4; /* skip mtime_high */
81
82 l = *parse++;
83 /* don't care about the file name, and skip checksum */
84 parse += l + 4;
85
86 *skip = parse - input;
87 return 1;
88}
89
90STATIC inline int INIT unlzo(u8 *input, int in_len,
91 int (*fill) (void *, unsigned int),
92 int (*flush) (void *, unsigned int),
93 u8 *output, int *posp,
94 void (*error_fn) (char *x))
95{
96 u8 skip = 0, r = 0;
97 u32 src_len, dst_len;
98 size_t tmp;
99 u8 *in_buf, *in_buf_save, *out_buf;
100 int obytes_processed = 0;
101
102 set_error_fn(error_fn);
103
104 if (output) {
105 out_buf = output;
106 } else if (!flush) {
107 error("NULL output pointer and no flush function provided");
108 goto exit;
109 } else {
110 out_buf = malloc(LZO_BLOCK_SIZE);
111 if (!out_buf) {
112 error("Could not allocate output buffer");
113 goto exit;
114 }
115 }
116
117 if (input && fill) {
118 error("Both input pointer and fill function provided, don't know what to do");
119 goto exit_1;
120 } else if (input) {
121 in_buf = input;
122 } else if (!fill || !posp) {
123 error("NULL input pointer and missing position pointer or fill function");
124 goto exit_1;
125 } else {
126 in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE));
127 if (!in_buf) {
128 error("Could not allocate input buffer");
129 goto exit_1;
130 }
131 }
132 in_buf_save = in_buf;
133
134 if (posp)
135 *posp = 0;
136
137 if (fill)
138 fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));
139
140 if (!parse_header(input, &skip)) {
141 error("invalid header");
142 goto exit_2;
143 }
144 in_buf += skip;
145
146 if (posp)
147 *posp = skip;
148
149 for (;;) {
150 /* read uncompressed block size */
151 dst_len = get_unaligned_be32(in_buf);
152 in_buf += 4;
153
154 /* exit if last block */
155 if (dst_len == 0) {
156 if (posp)
157 *posp += 4;
158 break;
159 }
160
161 if (dst_len > LZO_BLOCK_SIZE) {
162 error("dest len longer than block size");
163 goto exit_2;
164 }
165
166 /* read compressed block size, and skip block checksum info */
167 src_len = get_unaligned_be32(in_buf);
168 in_buf += 8;
169
170 if (src_len <= 0 || src_len > dst_len) {
171 error("file corrupted");
172 goto exit_2;
173 }
174
175 /* decompress */
176 tmp = dst_len;
177 r = lzo1x_decompress_safe((u8 *) in_buf, src_len,
178 out_buf, &tmp);
179
180 if (r != LZO_E_OK || dst_len != tmp) {
181 error("Compressed data violation");
182 goto exit_2;
183 }
184
185 obytes_processed += dst_len;
186 if (flush)
187 flush(out_buf, dst_len);
188 if (output)
189 out_buf += dst_len;
190 if (posp)
191 *posp += src_len + 12;
192 if (fill) {
193 in_buf = in_buf_save;
194 fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));
195 } else
196 in_buf += src_len;
197 }
198
199exit_2:
200 if (!input)
201 free(in_buf);
202exit_1:
203 if (!output)
204 free(out_buf);
205exit:
206 return obytes_processed;
207}
208
209#define decompress unlzo
diff --git a/lib/lzo/lzo1x_decompress.c b/lib/lzo/lzo1x_decompress.c
index 5dc6b29c1575..f2fd09850223 100644
--- a/lib/lzo/lzo1x_decompress.c
+++ b/lib/lzo/lzo1x_decompress.c
@@ -11,11 +11,13 @@
11 * Richard Purdie <rpurdie@openedhand.com> 11 * Richard Purdie <rpurdie@openedhand.com>
12 */ 12 */
13 13
14#ifndef STATIC
14#include <linux/module.h> 15#include <linux/module.h>
15#include <linux/kernel.h> 16#include <linux/kernel.h>
16#include <linux/lzo.h> 17#endif
17#include <asm/byteorder.h> 18
18#include <asm/unaligned.h> 19#include <asm/unaligned.h>
20#include <linux/lzo.h>
19#include "lzodefs.h" 21#include "lzodefs.h"
20 22
21#define HAVE_IP(x, ip_end, ip) ((size_t)(ip_end - ip) < (x)) 23#define HAVE_IP(x, ip_end, ip) ((size_t)(ip_end - ip) < (x))
@@ -244,9 +246,10 @@ lookbehind_overrun:
244 *out_len = op - out; 246 *out_len = op - out;
245 return LZO_E_LOOKBEHIND_OVERRUN; 247 return LZO_E_LOOKBEHIND_OVERRUN;
246} 248}
247 249#ifndef STATIC
248EXPORT_SYMBOL_GPL(lzo1x_decompress_safe); 250EXPORT_SYMBOL_GPL(lzo1x_decompress_safe);
249 251
250MODULE_LICENSE("GPL"); 252MODULE_LICENSE("GPL");
251MODULE_DESCRIPTION("LZO1X Decompressor"); 253MODULE_DESCRIPTION("LZO1X Decompressor");
252 254
255#endif
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index cd815ac2a50b..0fe48cd91ffa 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -235,3 +235,8 @@ quiet_cmd_lzma = LZMA $@
235cmd_lzma = (cat $(filter-out FORCE,$^) | \ 235cmd_lzma = (cat $(filter-out FORCE,$^) | \
236 lzma -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \ 236 lzma -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
237 (rm -f $@ ; false) 237 (rm -f $@ ; false)
238
239quiet_cmd_lzo = LZO $@
240cmd_lzo = (cat $(filter-out FORCE,$^) | \
241 lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
242 (rm -f $@ ; false)