lib: add support for LZO-compressed kernels

#ifndef DECOMPRESS_UNLZO_H

#define DECOMPRESS_UNLZO_H

int unlzo(unsigned char *inbuf, int len,

	int(*fill)(void*, unsigned int),

	int(*flush)(void*, unsigned int),

	unsigned char *output,

	int *pos,

	void(*error)(char *x));

#endif

config HAVE_KERNEL_LZMA

	bool

config HAVE_KERNEL_LZO

	bool

choice

	prompt "Kernel compression mode"

	default KERNEL_GZIP

	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA

	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_LZO

	help

	  The linux kernel is a kind of self-extracting executable.

	  Several compression algorithms are available, which differ

	bool "Gzip"

	depends on HAVE_KERNEL_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 KERNEL_BZIP2

	bool "Bzip2"

	  two. Compression is slowest.	The kernel size is about 33%

	  smaller with LZMA in comparison to gzip.

config KERNEL_LZO

	bool "LZO"

	depends on HAVE_KERNEL_LZO

	help

	  Its compression ratio is the poorest among the 4. The kernel

	  size is about about 10% bigger than gzip; however its speed

	  (both compression and decompression) is the fastest.

endchoice

config SWAP

/*

 * LZO decompressor for the Linux kernel. Code borrowed from the lzo

 * implementation by Markus Franz Xaver Johannes Oberhumer.

 *

 * Linux kernel adaptation:

 * Copyright (C) 2009

 * Albin Tonnerre, Free Electrons <albin.tonnerre@free-electrons.com>

 *

 * Original code:

 * Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer

 * All Rights Reserved.

 *

 * lzop and the LZO library are free software; you can redistribute them

 * and/or modify them under the terms of the GNU General Public License as

 * published by the Free Software Foundation; either version 2 of

 * the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; see the file COPYING.

 * If not, write to the Free Software Foundation, Inc.,

 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 *

 * Markus F.X.J. Oberhumer

 * <markus@oberhumer.com>

 * http://www.oberhumer.com/opensource/lzop/

 */

#ifdef STATIC

#include "lzo/lzo1x_decompress.c"

#else

#include <linux/slab.h>

#include <linux/decompress/unlzo.h>

#endif

#include <linux/types.h>

#include <linux/lzo.h>

#include <linux/decompress/mm.h>

#include <linux/compiler.h>

#include <asm/unaligned.h>

static const unsigned char lzop_magic[] = {

	0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a };

#define LZO_BLOCK_SIZE        (256*1024l)

#define HEADER_HAS_FILTER      0x00000800L

STATIC inline int INIT parse_header(u8 *input, u8 *skip)

{

	int l;

	u8 *parse = input;

	u8 level = 0;

	u16 version;

	/* read magic: 9 first bits */

	for (l = 0; l < 9; l++) {

		if (*parse++ != lzop_magic[l])

			return 0;

	}

	/* get version (2bytes), skip library version (2),

	 * 'need to be extracted' version (2) and

	 * method (1) */

	version = get_unaligned_be16(parse);

	parse += 7;

	if (version >= 0x0940)

		level = *parse++;

	if (get_unaligned_be32(parse) & HEADER_HAS_FILTER)

		parse += 8; /* flags + filter info */

	else

		parse += 4; /* flags */

	/* skip mode and mtime_low */

	parse += 8;

	if (version >= 0x0940)

		parse += 4;	/* skip mtime_high */

	l = *parse++;

	/* don't care about the file name, and skip checksum */

	parse += l + 4;

	*skip = parse - input;

	return 1;

}

STATIC inline int INIT unlzo(u8 *input, int in_len,

				int (*fill) (void *, unsigned int),

				int (*flush) (void *, unsigned int),

				u8 *output, int *posp,

				void (*error_fn) (char *x))

{

	u8 skip = 0, r = 0;

	u32 src_len, dst_len;

	size_t tmp;

	u8 *in_buf, *in_buf_save, *out_buf;

	int obytes_processed = 0;

	set_error_fn(error_fn);

	if (output) {

		out_buf = output;

	} else if (!flush) {

		error("NULL output pointer and no flush function provided");

		goto exit;

	} else {

		out_buf = malloc(LZO_BLOCK_SIZE);

		if (!out_buf) {

			error("Could not allocate output buffer");

			goto exit;

		}

	}

	if (input && fill) {

		error("Both input pointer and fill function provided, don't know what to do");

		goto exit_1;

	} else if (input) {

		in_buf = input;

	} else if (!fill || !posp) {

		error("NULL input pointer and missing position pointer or fill function");

		goto exit_1;

	} else {

		in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE));

		if (!in_buf) {

			error("Could not allocate input buffer");

			goto exit_1;

		}

	}

	in_buf_save = in_buf;

	if (posp)

		*posp = 0;

	if (fill)

		fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));

	if (!parse_header(input, &skip)) {

		error("invalid header");

		goto exit_2;

	}

	in_buf += skip;

	if (posp)

		*posp = skip;

	for (;;) {

		/* read uncompressed block size */

		dst_len = get_unaligned_be32(in_buf);

		in_buf += 4;

		/* exit if last block */

		if (dst_len == 0) {

			if (posp)

				*posp += 4;

			break;

		}

		if (dst_len > LZO_BLOCK_SIZE) {

			error("dest len longer than block size");

			goto exit_2;

		}

		/* read compressed block size, and skip block checksum info */

		src_len = get_unaligned_be32(in_buf);

		in_buf += 8;

		if (src_len <= 0 || src_len > dst_len) {

			error("file corrupted");

			goto exit_2;

		}

		/* decompress */

		tmp = dst_len;

		r = lzo1x_decompress_safe((u8 *) in_buf, src_len,

						out_buf, &tmp);

		if (r != LZO_E_OK || dst_len != tmp) {

			error("Compressed data violation");

			goto exit_2;

		}

		obytes_processed += dst_len;

		if (flush)

			flush(out_buf, dst_len);

		if (output)

			out_buf += dst_len;

		if (posp)

			*posp += src_len + 12;

		if (fill) {

			in_buf = in_buf_save;

			fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));

		} else

			in_buf += src_len;

	}

exit_2:

	if (!input)

		free(in_buf);

exit_1:

	if (!output)

		free(out_buf);

exit:

	return obytes_processed;

}

#define decompress unlzo

 *  Richard Purdie <rpurdie@openedhand.com>

 */

#ifndef STATIC

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/lzo.h>

#include <asm/byteorder.h>

#endif

#include <asm/unaligned.h>

#include <linux/lzo.h>

#include "lzodefs.h"

#define HAVE_IP(x, ip_end, ip) ((size_t)(ip_end - ip) < (x))

	*out_len = op - out;

	return LZO_E_LOOKBEHIND_OVERRUN;

}

#ifndef STATIC

EXPORT_SYMBOL_GPL(lzo1x_decompress_safe);

MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("LZO1X Decompressor");

#endif

cmd_lzma = (cat $(filter-out FORCE,$^) | \

	lzma -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \

	(rm -f $@ ; false)

quiet_cmd_lzo = LZO    $@

cmd_lzo = (cat $(filter-out FORCE,$^) | \

	lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \

	(rm -f $@ ; false)