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- #ifndef _IPXE_DEFLATE_H
- #define _IPXE_DEFLATE_H
-
- /** @file
- *
- * DEFLATE decompression algorithm
- *
- */
-
- FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
-
- #include <stdint.h>
- #include <string.h>
- #include <ipxe/uaccess.h>
-
- /** Compression formats */
- enum deflate_format {
- /** Raw DEFLATE data (no header or footer) */
- DEFLATE_RAW,
- /** ZLIB header and footer */
- DEFLATE_ZLIB,
- };
-
- /** Block header length (in bits) */
- #define DEFLATE_HEADER_BITS 3
-
- /** Block header final block flags bit */
- #define DEFLATE_HEADER_BFINAL_BIT 0
-
- /** Block header type LSB */
- #define DEFLATE_HEADER_BTYPE_LSB 1
-
- /** Block header type mask */
- #define DEFLATE_HEADER_BTYPE_MASK 0x03
-
- /** Block header type: literal data */
- #define DEFLATE_HEADER_BTYPE_LITERAL 0
-
- /** Block header type: static Huffman alphabet */
- #define DEFLATE_HEADER_BTYPE_STATIC 1
-
- /** Block header type: dynamic Huffman alphabet */
- #define DEFLATE_HEADER_BTYPE_DYNAMIC 2
-
- /** Literal header LEN/NLEN field length (in bits) */
- #define DEFLATE_LITERAL_LEN_BITS 16
-
- /** Dynamic header length (in bits) */
- #define DEFLATE_DYNAMIC_BITS 14
-
- /** Dynamic header HLIT field LSB */
- #define DEFLATE_DYNAMIC_HLIT_LSB 0
-
- /** Dynamic header HLIT field mask */
- #define DEFLATE_DYNAMIC_HLIT_MASK 0x1f
-
- /** Dynamic header HDIST field LSB */
- #define DEFLATE_DYNAMIC_HDIST_LSB 5
-
- /** Dynamic header HDIST field mask */
- #define DEFLATE_DYNAMIC_HDIST_MASK 0x1f
-
- /** Dynamic header HCLEN field LSB */
- #define DEFLATE_DYNAMIC_HCLEN_LSB 10
-
- /** Dynamic header HCLEN field mask */
- #define DEFLATE_DYNAMIC_HCLEN_MASK 0x0f
-
- /** Dynamic header code length length (in bits) */
- #define DEFLATE_CODELEN_BITS 3
-
- /** Maximum length of a Huffman symbol (in bits) */
- #define DEFLATE_HUFFMAN_BITS 15
-
- /** Quick lookup length for a Huffman symbol (in bits)
- *
- * This is a policy decision.
- */
- #define DEFLATE_HUFFMAN_QL_BITS 7
-
- /** Quick lookup shift */
- #define DEFLATE_HUFFMAN_QL_SHIFT ( 16 - DEFLATE_HUFFMAN_QL_BITS )
-
- /** Literal/length end of block code */
- #define DEFLATE_LITLEN_END 256
-
- /** Maximum value of a literal/length code */
- #define DEFLATE_LITLEN_MAX_CODE 287
-
- /** Maximum value of a distance code */
- #define DEFLATE_DISTANCE_MAX_CODE 31
-
- /** Maximum value of a code length code */
- #define DEFLATE_CODELEN_MAX_CODE 18
-
- /** ZLIB header length (in bits) */
- #define ZLIB_HEADER_BITS 16
-
- /** ZLIB header compression method LSB */
- #define ZLIB_HEADER_CM_LSB 0
-
- /** ZLIB header compression method mask */
- #define ZLIB_HEADER_CM_MASK 0x0f
-
- /** ZLIB header compression method: DEFLATE */
- #define ZLIB_HEADER_CM_DEFLATE 8
-
- /** ZLIB header preset dictionary flag bit */
- #define ZLIB_HEADER_FDICT_BIT 13
-
- /** ZLIB ADLER32 length (in bits) */
- #define ZLIB_ADLER32_BITS 32
-
- /** A Huffman-coded set of symbols of a given length */
- struct deflate_huf_symbols {
- /** Length of Huffman-coded symbols */
- uint8_t bits;
- /** Shift to normalise symbols of this length to 16 bits */
- uint8_t shift;
- /** Number of Huffman-coded symbols having this length */
- uint16_t freq;
- /** First symbol of this length (normalised to 16 bits)
- *
- * Stored as a 32-bit value to allow the value 0x10000 to be
- * used for empty sets of symbols longer than the maximum
- * utilised length.
- */
- uint32_t start;
- /** Raw symbols having this length */
- uint16_t *raw;
- };
-
- /** A Huffman-coded alphabet */
- struct deflate_alphabet {
- /** Huffman-coded symbol set for each length */
- struct deflate_huf_symbols huf[DEFLATE_HUFFMAN_BITS];
- /** Quick lookup table */
- uint8_t lookup[ 1 << DEFLATE_HUFFMAN_QL_BITS ];
- /** Raw symbols
- *
- * Ordered by Huffman-coded symbol length, then by symbol
- * value. This field has a variable length.
- */
- uint16_t raw[0];
- };
-
- /** A static Huffman alphabet length pattern */
- struct deflate_static_length_pattern {
- /** Length pair */
- uint8_t fill;
- /** Repetition count */
- uint8_t count;
- } __attribute__ (( packed ));
-
- /** Decompressor */
- struct deflate {
- /** Resume point
- *
- * Used as the target of a computed goto to jump to the
- * appropriate point within the state machine.
- */
- void *resume;
- /** Format */
- enum deflate_format format;
-
- /** Accumulator */
- uint32_t accumulator;
- /** Bit-reversed accumulator
- *
- * Don't ask.
- */
- uint32_t rotalumucca;
- /** Number of bits within the accumulator */
- unsigned int bits;
-
- /** Current block header */
- unsigned int header;
- /** Remaining length of data (e.g. within a literal block) */
- size_t remaining;
- /** Current length index within a set of code lengths */
- unsigned int length_index;
- /** Target length index within a set of code lengths */
- unsigned int length_target;
- /** Current length within a set of code lengths */
- unsigned int length;
- /** Number of extra bits required */
- unsigned int extra_bits;
- /** Length of a duplicated string */
- size_t dup_len;
- /** Distance of a duplicated string */
- size_t dup_distance;
-
- /** Literal/length Huffman alphabet */
- struct deflate_alphabet litlen;
- /** Literal/length raw symbols
- *
- * Must immediately follow the literal/length Huffman alphabet.
- */
- uint16_t litlen_raw[ DEFLATE_LITLEN_MAX_CODE + 1 ];
- /** Number of symbols in the literal/length Huffman alphabet */
- unsigned int litlen_count;
-
- /** Distance and code length Huffman alphabet
- *
- * The code length Huffman alphabet has a maximum Huffman
- * symbol length of 7 and a maximum code value of 18, and is
- * thus strictly smaller than the distance Huffman alphabet.
- * Since we never need both alphabets simultaneously, we can
- * reuse the storage space for the distance alphabet to
- * temporarily hold the code length alphabet.
- */
- struct deflate_alphabet distance_codelen;
- /** Distance and code length raw symbols
- *
- * Must immediately follow the distance and code length
- * Huffman alphabet.
- */
- uint16_t distance_codelen_raw[ DEFLATE_DISTANCE_MAX_CODE + 1 ];
- /** Number of symbols in the distance Huffman alphabet */
- unsigned int distance_count;
-
- /** Huffman code lengths
- *
- * The literal/length and distance code lengths are
- * constructed as a single set of lengths.
- *
- * The code length Huffman alphabet has a maximum code value
- * of 18 and the set of lengths is thus strictly smaller than
- * the combined literal/length and distance set of lengths.
- * Since we never need both alphabets simultaneously, we can
- * reuse the storage space for the literal/length and distance
- * code lengths to temporarily hold the code length code
- * lengths.
- */
- uint8_t lengths[ ( ( DEFLATE_LITLEN_MAX_CODE + 1 ) +
- ( DEFLATE_DISTANCE_MAX_CODE + 1 ) +
- 1 /* round up */ ) / 2 ];
- };
-
- /** A chunk of data */
- struct deflate_chunk {
- /** Data */
- userptr_t data;
- /** Current offset */
- size_t offset;
- /** Length of data */
- size_t len;
- };
-
- /**
- * Initialise chunk of data
- *
- * @v chunk Chunk of data to initialise
- * @v data Data
- * @v offset Starting offset
- * @v len Length
- */
- static inline __attribute__ (( always_inline )) void
- deflate_chunk_init ( struct deflate_chunk *chunk, userptr_t data,
- size_t offset, size_t len ) {
-
- chunk->data = data;
- chunk->offset = offset;
- chunk->len = len;
- }
-
- /**
- * Check if decompression has finished
- *
- * @v deflate Decompressor
- * @ret finished Decompression has finished
- */
- static inline int deflate_finished ( struct deflate *deflate ) {
- return ( deflate->resume == NULL );
- }
-
- extern void deflate_init ( struct deflate *deflate,
- enum deflate_format format );
- extern int deflate_inflate ( struct deflate *deflate,
- struct deflate_chunk *in,
- struct deflate_chunk *out );
-
- #endif /* _IPXE_DEFLATE_H */
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