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Diffstat (limited to 'arch/powerpc/boot/gunzip_util.h')
| -rw-r--r-- | arch/powerpc/boot/gunzip_util.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/powerpc/boot/gunzip_util.h b/arch/powerpc/boot/gunzip_util.h new file mode 100644 index 00000000000..b3dfa6e87b3 --- /dev/null +++ b/arch/powerpc/boot/gunzip_util.h @@ -0,0 +1,45 @@ +/* + * 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_ */ |