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/*
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* Decompression convenience functions
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*
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* Copyright 2007 David Gibson, IBM Corporation.
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#ifndef _PPC_BOOT_GUNZIP_UTIL_H_
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#define _PPC_BOOT_GUNZIP_UTIL_H_
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#include "zlib.h"
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/*
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* These functions are designed to make life easy for decompressing
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* kernel images, initrd images or any other gzip compressed image,
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* particularly if its useful to decompress part of the image (e.g. to
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* examine headers) before decompressing the remainder.
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*
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* To use:
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* - declare a gunzip_state structure
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* - use gunzip_start() to initialize the state, associating it
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* with a stream of compressed data
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* - use gunzip_partial(), gunzip_exactly() and gunzip_discard()
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* in any combination to extract pieces of data from the stream
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* - Finally use gunzip_finish() to extract the tail of the
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* compressed stream and wind up zlib
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*/
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/* scratch space for gunzip; 46912 is from zlib_inflate_workspacesize() */
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#define GUNZIP_SCRATCH_SIZE 46912
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struct gunzip_state {
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z_stream s;
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char scratch[46912];
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};
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void gunzip_start(struct gunzip_state *state, void *src, int srclen);
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int gunzip_partial(struct gunzip_state *state, void *dst, int dstlen);
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void gunzip_exactly(struct gunzip_state *state, void *dst, int len);
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void gunzip_discard(struct gunzip_state *state, int len);
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int gunzip_finish(struct gunzip_state *state, void *dst, int len);
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#endif /* _PPC_BOOT_GUNZIP_UTIL_H_ */
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