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/*
* 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_ */
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