kernel_optimize_test/lib/decompress.c
Albin Tonnerre cacb246f8d Add LZO compression support for initramfs and old-style initrd
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>
2010-01-11 09:34:05 -08:00

60 lines
1.2 KiB
C

/*
* decompress.c
*
* Detect the decompression method based on magic number
*/
#include <linux/decompress/generic.h>
#include <linux/decompress/bunzip2.h>
#include <linux/decompress/unlzma.h>
#include <linux/decompress/inflate.h>
#include <linux/decompress/unlzo.h>
#include <linux/types.h>
#include <linux/string.h>
#ifndef CONFIG_DECOMPRESS_GZIP
# define gunzip NULL
#endif
#ifndef CONFIG_DECOMPRESS_BZIP2
# define bunzip2 NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZMA
# define unlzma NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZO
# define unlzo NULL
#endif
static const struct compress_format {
unsigned char magic[2];
const char *name;
decompress_fn decompressor;
} compressed_formats[] = {
{ {037, 0213}, "gzip", gunzip },
{ {037, 0236}, "gzip", gunzip },
{ {0x42, 0x5a}, "bzip2", bunzip2 },
{ {0x5d, 0x00}, "lzma", unlzma },
{ {0x89, 0x4c}, "lzo", unlzo },
{ {0, 0}, NULL, NULL }
};
decompress_fn decompress_method(const unsigned char *inbuf, int len,
const char **name)
{
const struct compress_format *cf;
if (len < 2)
return NULL; /* Need at least this much... */
for (cf = compressed_formats; cf->name; cf++) {
if (!memcmp(inbuf, cf->magic, 2))
break;
}
if (name)
*name = cf->name;
return cf->decompressor;
}