[deliverable/linux.git] / arch / powerpc / boot / gunzip_util.h

/*
 * Decompression convenience functions
 *
 * Copyright 2007 David Gibson, IBM Corporation.
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */
#ifndef _PPC_BOOT_GUNZIP_UTIL_H_
#define _PPC_BOOT_GUNZIP_UTIL_H_

#include "zlib.h"

/*
 * These functions are designed to make life easy for decompressing
 * kernel images, initrd images or any other gzip compressed image,
 * particularly if its useful to decompress part of the image (e.g. to
 * examine headers) before decompressing the remainder.
 *
 * To use:
 *     - declare a gunzip_state structure
 *     - use gunzip_start() to initialize the state, associating it
 *       with a stream of compressed data
 *     - use gunzip_partial(), gunzip_exactly() and gunzip_discard()
 *       in any combination to extract pieces of data from the stream
 *     - Finally use gunzip_finish() to extract the tail of the
 *       compressed stream and wind up zlib
 */

/* scratch space for gunzip; 46912 is from zlib_inflate_workspacesize() */
#define GUNZIP_SCRATCH_SIZE	46912

struct gunzip_state {
	z_stream s;
	char scratch[46912];
};

void gunzip_start(struct gunzip_state *state, void *src, int srclen);
int gunzip_partial(struct gunzip_state *state, void *dst, int dstlen);
void gunzip_exactly(struct gunzip_state *state, void *dst, int len);
void gunzip_discard(struct gunzip_state *state, int len);
int gunzip_finish(struct gunzip_state *state, void *dst, int len);

#endif /* _PPC_BOOT_GUNZIP_UTIL_H_ */
Commit	Line	Data
ad9d2716 DG	1	/*
	2	* Decompression convenience functions
	3	*
	4	* Copyright 2007 David Gibson, IBM Corporation.
	5	*
	6	* This file is licensed under the terms of the GNU General Public
	7	* License version 2. This program is licensed "as is" without any
	8	* warranty of any kind, whether express or implied.
	9	*/
	10	#ifndef _PPC_BOOT_GUNZIP_UTIL_H_
	11	#define _PPC_BOOT_GUNZIP_UTIL_H_
	12
	13	#include "zlib.h"
	14
7850ad5c DG	15	/*
	16	* These functions are designed to make life easy for decompressing
	17	* kernel images, initrd images or any other gzip compressed image,
	18	* particularly if its useful to decompress part of the image (e.g. to
	19	* examine headers) before decompressing the remainder.
	20	*
	21	* To use:
	22	* - declare a gunzip_state structure
	23	* - use gunzip_start() to initialize the state, associating it
	24	* with a stream of compressed data
	25	* - use gunzip_partial(), gunzip_exactly() and gunzip_discard()
	26	* in any combination to extract pieces of data from the stream
	27	* - Finally use gunzip_finish() to extract the tail of the
	28	* compressed stream and wind up zlib
	29	*/
	30
ad9d2716 DG	31	/* scratch space for gunzip; 46912 is from zlib_inflate_workspacesize() */
	32	#define GUNZIP_SCRATCH_SIZE 46912
	33
	34	struct gunzip_state {
	35	z_stream s;
	36	char scratch[46912];
	37	};
	38
	39	void gunzip_start(struct gunzip_state state, void src, int srclen);
	40	int gunzip_partial(struct gunzip_state state, void dst, int dstlen);
	41	void gunzip_exactly(struct gunzip_state state, void dst, int len);
	42	void gunzip_discard(struct gunzip_state *state, int len);
	43	int gunzip_finish(struct gunzip_state state, void dst, int len);
	44
	45	#endif /* _PPC_BOOT_GUNZIP_UTIL_H_ */