Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * 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_ */