4 * LZX decompression routines, originally based on code taken from cabextract
5 * v0.5, which was, itself, a modified version of the lzx decompression code
10 * Copyright (C) 2012 Eric Biggers
12 * This file is part of wimlib, a library for working with WIM files.
14 * wimlib is free software; you can redistribute it and/or modify it under the
15 * terms of the GNU General Public License as published by the Free
16 * Software Foundation; either version 3 of the License, or (at your option)
19 * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
20 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
21 * A PARTICULAR PURPOSE. See the GNU General Public License for more
24 * You should have received a copy of the GNU General Public License
25 * along with wimlib; if not, see http://www.gnu.org/licenses/.
29 * LZX is a LZ77 and Huffman-code based compression format that has many
30 * similarities to the DEFLATE format used in zlib. The compression ratio is as
31 * good or better than DEFLATE. However, in WIM files only up to 32768 bytes of
32 * data can ever compressed be in the same LZX block, so a .tar.gz file could
33 * potentially be smaller than a WIM file that uses LZX compression because it
34 * can use a larger LZ77 window size.
36 * Some notes on the LZX compression format as used in Windows Imaging (WIM)
39 * A compressed WIM resource consists of a table of chunk offsets followed by
40 * the compressed chunks themselves. All compressed chunks except possibly the
41 * last decompress to WIM_CHUNK_SIZE (= 32768) bytes. This is quite similar to
42 * the cabinet (.cab) file format, but they are not the same. According to the
43 * cabinet format documentation, the LZX block size is independent from the
44 * CFDATA blocks, and a LZX block may span several CFDATA blocks. However, in
45 * WIMs, LZX blocks do not appear to ever span multiple WIM chunks. Note that
46 * this means any WIM chunk may be decompressed or compressed independently from
47 * any other chunk, which is convenient.
49 * A LZX compressed WIM chunk contains one or more LZX blocks of the aligned,
50 * verbatim, or uncompressed block types. For aligned and verbatim blocks, the
51 * size of the block in uncompressed bytes is specified by a bit following the 3
52 * bits that specify the block type, possibly followed by an additional 16 bits.
53 * '1' means to use the default block size (equal to 32768, the size of a WIM
54 * chunk--- and this seems to only be valid for the first LZX block in a WIM
55 * chunk), while '0' means that the block size is provided by the next 16 bits.
57 * The cabinet format, as documented, allows for the possibility that a
58 * compressed CFDATA chunk is up to 6144 bytes larger than the data it
59 * uncompresses to. However, in the WIM format it appears that every chunk that
60 * would be 32768 bytes or more when compressed is actually stored fully
63 * The 'e8' preprocessing step that changes x86 call instructions to use
64 * absolute offsets instead of relative offsets relies on a filesize parameter.
65 * There is no such parameter for this in the WIM files (even though the size of
66 * the file resource could be used for this purpose), and instead a magic file
67 * size of 12000000 is used. The 'e8' preprocessing is always done, and there
68 * is no bit to indicate whether it is done or not.
72 * Some more notes about errors in Microsoft's LZX documentation:
74 * Microsoft's LZX document and their implementation of the com.ms.util.cab Java
75 * package do not concur.
77 * In the LZX document, there is a table showing the correlation between window
78 * size and the number of position slots. It states that the 1MB window = 40
79 * slots and the 2MB window = 42 slots. In the implementation, 1MB = 42 slots,
80 * 2MB = 50 slots. The actual calculation is 'find the first slot whose position
81 * base is equal to or more than the required window size'. This would explain
82 * why other tables in the document refer to 50 slots rather than 42.
84 * The constant NUM_PRIMARY_LENS used in the decompression pseudocode is not
85 * defined in the specification.
87 * The LZX document states that aligned offset blocks have their aligned offset
88 * huffman tree AFTER the main and length trees. The implementation suggests
89 * that the aligned offset tree is BEFORE the main and length trees.
91 * The LZX document decoding algorithm states that, in an aligned offset block,
92 * if an extra_bits value is 1, 2 or 3, then that number of bits should be read
93 * and the result added to the match offset. This is correct for 1 and 2, but
94 * not 3, where just a huffman symbol (using the aligned tree) should be read.
96 * Regarding the E8 preprocessing, the LZX document states 'No translation may
97 * be performed on the last 6 bytes of the input block'. This is correct.
98 * However, the pseudocode provided checks for the *E8 leader* up to the last 6
99 * bytes. If the leader appears between -10 and -7 bytes from the end, this
100 * would cause the next four bytes to be modified, at least one of which would
101 * be in the last 6 bytes, which is not allowed according to the spec.
103 * The specification states that the huffman trees must always contain at least
104 * one element. However, many CAB files contain blocks where the length tree is
105 * completely empty (because there are no matches), and this is expected to
114 /* Huffman decoding tables and maps from symbols to code lengths. */
117 u16 maintree_decode_table[(1 << LZX_MAINTREE_TABLEBITS) +
118 (LZX_MAINTREE_NUM_SYMBOLS * 2)];
119 u8 maintree_lens[LZX_MAINTREE_NUM_SYMBOLS];
122 u16 lentree_decode_table[(1 << LZX_LENTREE_TABLEBITS) +
123 (LZX_LENTREE_NUM_SYMBOLS * 2)];
124 u8 lentree_lens[LZX_LENTREE_NUM_SYMBOLS];
127 u16 alignedtree_decode_table[(1 << LZX_ALIGNEDTREE_TABLEBITS) +
128 (LZX_ALIGNEDTREE_NUM_SYMBOLS * 2)];
129 u8 alignedtree_lens[LZX_ALIGNEDTREE_NUM_SYMBOLS];
134 * Reads a Huffman-encoded symbol using the pre-tree.
136 static inline int read_huffsym_using_pretree(struct input_bitstream *istream,
137 const u16 pretree_decode_table[],
138 const u8 pretree_lens[], uint *n)
140 return read_huffsym(istream, pretree_decode_table, pretree_lens,
141 LZX_PRETREE_NUM_SYMBOLS, LZX_PRETREE_TABLEBITS, n,
142 LZX_MAX_CODEWORD_LEN);
145 /* Reads a Huffman-encoded symbol using the main tree. */
146 static inline int read_huffsym_using_maintree(struct input_bitstream *istream,
147 const struct lzx_tables *tables,
150 return read_huffsym(istream, tables->maintree_decode_table,
151 tables->maintree_lens, LZX_MAINTREE_NUM_SYMBOLS,
152 LZX_MAINTREE_TABLEBITS, n, LZX_MAX_CODEWORD_LEN);
155 /* Reads a Huffman-encoded symbol using the length tree. */
156 static inline int read_huffsym_using_lentree(struct input_bitstream *istream,
157 const struct lzx_tables *tables,
160 return read_huffsym(istream, tables->lentree_decode_table,
161 tables->lentree_lens, LZX_LENTREE_NUM_SYMBOLS,
162 LZX_LENTREE_TABLEBITS, n, LZX_MAX_CODEWORD_LEN);
165 /* Reads a Huffman-encoded symbol using the aligned offset tree. */
166 static inline int read_huffsym_using_alignedtree(struct input_bitstream *istream,
167 const struct lzx_tables *tables,
170 return read_huffsym(istream, tables->alignedtree_decode_table,
171 tables->alignedtree_lens,
172 LZX_ALIGNEDTREE_NUM_SYMBOLS,
173 LZX_ALIGNEDTREE_TABLEBITS, n, 8);
177 * Reads the pretree from the input, then uses the pretree to decode @num_lens
178 * code length values from the input.
180 * @istream: The bit stream for the input. It is positioned on the beginning
181 * of the pretree for the code length values.
182 * @lens: An array that contains the length values from the previous time
183 * the code lengths for this Huffman tree were read, or all
184 * 0's if this is the first time.
185 * @num_lens: Number of length values to decode and return.
188 static int lzx_read_code_lens(struct input_bitstream *istream, u8 lens[],
191 /* Declare the decoding table and length table for the pretree. */
192 u16 pretree_decode_table[(1 << LZX_PRETREE_TABLEBITS) +
193 (LZX_PRETREE_NUM_SYMBOLS * 2)];
194 u8 pretree_lens[LZX_PRETREE_NUM_SYMBOLS];
199 /* Read the code lengths of the pretree codes. There are 20 lengths of
201 for (i = 0; i < LZX_PRETREE_NUM_SYMBOLS; i++) {
202 ret = bitstream_read_bits(istream, LZX_PRETREE_ELEMENT_SIZE,
206 pretree_lens[i] = len;
209 /* Make the decoding table for the pretree. */
210 ret = make_huffman_decode_table(pretree_decode_table,
211 LZX_PRETREE_NUM_SYMBOLS,
212 LZX_PRETREE_TABLEBITS,
214 LZX_MAX_CODEWORD_LEN);
218 /* Pointer past the last length value that needs to be filled in. */
219 u8 *lens_end = lens + num_lens;
223 /* Decode a symbol from the input. If the symbol is between 0
224 * and 16, it is the difference from the old length. If it is
225 * between 17 and 19, it is a special code that indicates that
226 * some number of the next lengths are all 0, or some number of
227 * the next lengths are all equal to the next symbol in the
235 ret = read_huffsym_using_pretree(istream, pretree_decode_table,
236 pretree_lens, &tree_code);
240 case 17: /* Run of 0's */
241 ret = bitstream_read_bits(istream, 4, &num_zeroes);
245 while (num_zeroes--) {
247 if (++lens == lens_end)
251 case 18: /* Longer run of 0's */
252 ret = bitstream_read_bits(istream, 5, &num_zeroes);
256 while (num_zeroes--) {
258 if (++lens == lens_end)
262 case 19: /* Run of identical lengths */
263 ret = bitstream_read_bits(istream, 1, &num_same);
268 ret = read_huffsym_using_pretree(istream,
269 pretree_decode_table,
270 pretree_lens, &code);
273 value = (char)*lens - (char)code;
278 if (++lens == lens_end)
282 default: /* Difference from old length. */
283 value = (char)*lens - (char)tree_code;
287 if (++lens == lens_end)
295 * Reads the header for an LZX-compressed block.
297 * @istream: The input bitstream.
298 * @block_size_ret: A pointer to an int into which the size of the block,
299 * in bytes, will be returned.
300 * @block_type_ret: A pointer to an int into which the type of the block
301 * (LZX_BLOCKTYPE_*) will be returned.
302 * @tables: A pointer to a lzx_tables structure in which the
303 * main tree, the length tree, and possibly the
304 * aligned offset tree will be constructed.
305 * @queue: A pointer to the least-recently-used queue into which
306 * R0, R1, and R2 will be written (only for uncompressed
307 * blocks, which contain this information in the header)
309 static int lzx_read_block_header(struct input_bitstream *istream,
310 int *block_size_ret, int *block_type_ret,
311 struct lzx_tables *tables,
312 struct lru_queue *queue)
322 ret = bitstream_ensure_bits(istream, 4);
324 ERROR("LZX input stream overrun");
328 /* The first three bits tell us what kind of block it is, and are one
329 * of the LZX_BLOCKTYPE_* values. */
330 block_type = bitstream_read_bits_nocheck(istream, 3);
332 /* The next bit indicates whether the block size is the default (32768),
333 * indicated by a 1 bit, or whether the block size is given by the next
334 * 16 bits, indicated by a 0 bit. */
335 s = bitstream_read_bits_nocheck(istream, 1);
338 block_size = 1 << 15;
340 ret = bitstream_read_bits(istream, 16, &block_size);
343 block_size = le16_to_cpu(block_size);
346 switch (block_type) {
347 case LZX_BLOCKTYPE_ALIGNED:
348 /* Read the path lengths for the elements of the aligned tree,
351 for (i = 0; i < LZX_ALIGNEDTREE_NUM_SYMBOLS; i++) {
352 ret = bitstream_read_bits(istream,
353 LZX_ALIGNEDTREE_ELEMENT_SIZE,
357 tables->alignedtree_lens[i] = len;
360 LZX_DEBUG("Building the aligned tree.");
361 ret = make_huffman_decode_table(tables->alignedtree_decode_table,
362 LZX_ALIGNEDTREE_NUM_SYMBOLS,
363 LZX_ALIGNEDTREE_TABLEBITS,
364 tables->alignedtree_lens,
367 ERROR("lzx_decompress(): Failed to make the decode "
368 "table for the aligned offset tree");
372 /* Fall though, since the rest of the header for aligned offset
373 * blocks is the same as that for verbatim blocks */
375 case LZX_BLOCKTYPE_VERBATIM:
376 if (block_type == LZX_BLOCKTYPE_VERBATIM)
377 LZX_DEBUG("Found verbatim block.");
379 LZX_DEBUG("Reading path lengths for main tree.");
380 /* Read the path lengths for the first 256 elements of the main
382 ret = lzx_read_code_lens(istream, tables->maintree_lens,
385 ERROR("lzx_decompress(): Failed to read the code "
386 "lengths for the first 256 elements of the "
391 /* Read the path lengths for the remaining elements of the main
393 LZX_DEBUG("Reading path lengths for remaining elements of "
394 "main tree (%d elements).",
395 LZX_MAINTREE_NUM_SYMBOLS - LZX_NUM_CHARS);
396 ret = lzx_read_code_lens(istream,
397 tables->maintree_lens + LZX_NUM_CHARS,
398 LZX_MAINTREE_NUM_SYMBOLS - LZX_NUM_CHARS);
400 ERROR("lzx_decompress(): Failed to read the path "
401 "lengths for the remaining elements of the main "
406 LZX_DEBUG("Building the Huffman decoding "
407 "table for the main tree.");
409 ret = make_huffman_decode_table(tables->maintree_decode_table,
410 LZX_MAINTREE_NUM_SYMBOLS,
411 LZX_MAINTREE_TABLEBITS,
412 tables->maintree_lens,
413 LZX_MAX_CODEWORD_LEN);
415 ERROR("lzx_decompress(): Failed to make the decode "
416 "table for the main tree");
420 LZX_DEBUG("Reading path lengths for the length tree.");
421 ret = lzx_read_code_lens(istream, tables->lentree_lens,
422 LZX_LENTREE_NUM_SYMBOLS);
424 ERROR("lzx_decompress(): Failed to read the path "
425 "lengths for the length tree");
429 LZX_DEBUG("Building the length tree.");
430 ret = make_huffman_decode_table(tables->lentree_decode_table,
431 LZX_LENTREE_NUM_SYMBOLS,
432 LZX_LENTREE_TABLEBITS,
433 tables->lentree_lens,
434 LZX_MAX_CODEWORD_LEN);
436 ERROR("lzx_decompress(): Failed to build the length "
443 case LZX_BLOCKTYPE_UNCOMPRESSED:
444 LZX_DEBUG("Found uncompressed block.");
445 ret = align_input_bitstream(istream, true);
448 ret = bitstream_read_bytes(istream, sizeof(R), R);
451 queue->R0 = le32_to_cpu(R[0]);
452 queue->R1 = le32_to_cpu(R[1]);
453 queue->R2 = le32_to_cpu(R[2]);
456 LZX_DEBUG("Found invalid block.");
459 *block_type_ret = block_type;
460 *block_size_ret = block_size;
465 * Decodes a compressed literal match value. It refers to some match_offset to
466 * a point earlier in the window, and some match_len, for which the data is to
467 * be copied to the current position in the window.
469 * @main_element: The start of the match data, as decoded using the main
471 * @block_type: The type of the block (LZX_BLOCKTYPE_ALIGNED or
472 * LZX_BLOCKTYPE_VERBATIM)
473 * @bytes_remaining: The amount of uncompressed data remaining to be
474 * uncompressed. It is an error if the match
475 * is longer than @bytes_remaining.
476 * @window: A pointer to the window into which the uncompressed
477 * data is being written.
478 * @window_pos: The current position in the window.
479 * @tables: Contains the Huffman tables for the block (main,
480 * length, and also aligned offset only for
481 * LZX_BLOCKTYPE_ALIGNED)
482 * @queue: The least-recently used queue for match offsets.
483 * @istream: The input bitstream.
485 * Returns the length of the match, or -1 on error (match would exceed
486 * the amount of data needing to be uncompressed, or match refers to data before
487 * the window, or the input bitstream ended unexpectedly).
489 static int lzx_decode_match(int main_element, int block_type,
490 int bytes_remaining, u8 *window, int window_pos,
491 const struct lzx_tables *tables,
492 struct lru_queue *queue,
493 struct input_bitstream *istream)
508 /* The main element is offset by 256 because values under 256 indicate a
510 main_element -= LZX_NUM_CHARS;
512 /* The length header consists of the lower 3 bits of the main element.
513 * The position slot is the rest of it. */
514 length_header = main_element & LZX_NUM_PRIMARY_LENS;
515 position_slot = main_element >> 3;
517 /* If the length_header is less than LZX_NUM_PRIMARY_LENS (= 7), it
518 * gives the match length as the offset from LZX_MIN_MATCH. Otherwise,
519 * the length is given by an additional symbol encoded using the length
520 * tree, offset by 9 (LZX_MIN_MATCH + LZX_NUM_PRIMARY_LENS) */
521 match_len = LZX_MIN_MATCH + length_header;
522 if (length_header == LZX_NUM_PRIMARY_LENS) {
523 ret = read_huffsym_using_lentree(istream, tables,
527 match_len += additional_len;
531 /* If the position_slot is 0, 1, or 2, the match offset is retrieved
532 * from the LRU queue. Otherwise, the match offset is not in the LRU
534 switch (position_slot) {
536 match_offset = queue->R0;
539 match_offset = queue->R1;
540 swap(queue->R0, queue->R1);
543 /* The queue doesn't work quite the same as a real LRU queue,
544 * since using the R2 offset doesn't bump the R1 offset down to
546 match_offset = queue->R2;
547 swap(queue->R0, queue->R2);
550 /* Otherwise, the offset was not encoded as one the offsets in
551 * the queue. Depending on the position slot, there is a
552 * certain number of extra bits that need to be read to fully
553 * decode the match offset. */
555 /* Look up the number of extra bits that need to be read. */
556 num_extra_bits = lzx_extra_bits[position_slot];
558 /* For aligned blocks, if there are at least 3 extra bits, the
559 * actual number of extra bits is 3 less, and they encode a
560 * number of 8-byte words that are added to the offset; there
561 * is then an additional symbol read using the aligned tree that
562 * specifies the actual byte alignment. */
563 if (block_type == LZX_BLOCKTYPE_ALIGNED && num_extra_bits >= 3) {
565 /* There is an error in the LZX "specification" at this
566 * point; it indicates that a Huffman symbol is to be
567 * read only if num_extra_bits is greater than 3, but
568 * actually it is if num_extra_bits is greater than or
569 * equal to 3. (Note that in the case with
570 * num_extra_bits == 3, the assignment to verbatim_bits
571 * will just set it to 0. ) */
572 ret = bitstream_read_bits(istream, num_extra_bits - 3,
579 ret = read_huffsym_using_alignedtree(istream, tables,
584 /* For non-aligned blocks, or for aligned blocks with
585 * less than 3 extra bits, the extra bits are added
586 * directly to the match offset, and the correction for
587 * the alignment is taken to be 0. */
588 ret = bitstream_read_bits(istream, num_extra_bits,
596 /* Calculate the match offset. */
597 match_offset = lzx_position_base[position_slot] + verbatim_bits +
600 /* Update the LRU queue. */
601 queue->R2 = queue->R1;
602 queue->R1 = queue->R0;
603 queue->R0 = match_offset;
607 /* Verify that the match is in the bounds of the part of the window
608 * currently in use, then copy the source of the match to the current
610 match_dest = window + window_pos;
611 match_src = match_dest - match_offset;
613 if (match_len > bytes_remaining) {
614 ERROR("lzx_decode_match(): Match of length %d bytes overflows "
615 "uncompressed block size", match_len);
619 if (match_src < window) {
620 ERROR("lzx_decode_match(): Match of length %d bytes references "
621 "data before window (match_offset = %d, window_pos = %d)",
622 match_len, match_offset, window_pos);
627 printf("Match: src %u, dst %u, len %u\n", match_src - window,
631 for (i = 0; i < match_len; i++) {
632 match_dest[i] = match_src[i];
633 putchar(match_src[i]);
638 for (i = 0; i < match_len; i++)
639 match_dest[i] = match_src[i];
647 /* Undo the 'E8' preprocessing, where the targets of x86 CALL instructions were
648 * changed from relative offsets to absolute offsets. This type of
649 * preprocessing can be used on any binary data even if it is not actually
650 * machine code. It seems to always be used in WIM files, even though there is
651 * no bit to indicate that it actually is used, unlike in the LZX compressed
652 * format as used in other file formats, where a bit is reserved for that
654 static void undo_call_insn_preprocessing(u8 uncompressed_data[],
655 uint uncompressed_data_len)
658 int file_size = LZX_MAGIC_FILESIZE;
662 /* Not enabled in the last 6 bytes, which means the 5-byte call
663 * instruction cannot start in the last *10* bytes. */
664 while (i < uncompressed_data_len - 10) {
665 if (uncompressed_data[i] != 0xe8) {
669 abs_offset = le32_to_cpu(*(int32_t*)(uncompressed_data + i + 1));
671 if (abs_offset >= -i && abs_offset < file_size) {
672 if (abs_offset >= 0) {
673 /* "good translation" */
674 rel_offset = abs_offset - i;
676 /* "compensating translation" */
677 rel_offset = abs_offset + file_size;
679 *(int32_t*)(uncompressed_data + i + 1) =
680 cpu_to_le32(rel_offset);
687 * Decompresses a compressed block of data from which the header has already
690 * @block_type: The type of the block (LZX_BLOCKTYPE_VERBATIM or
691 * LZX_BLOCKTYPE_ALIGNED)
692 * @block_size: The size of the block, in bytes.
693 * @window: Pointer to the decompression window.
694 * @window_pos: The current position in the window. Will be 0 for the first
696 * @tables: The Huffman decoding tables for the block (main, length, and
697 * aligned offset, the latter only for LZX_BLOCKTYPE_ALIGNED)
698 * @queue: The least-recently-used queue for match offsets.
699 * @istream: The input bitstream for the compressed literals.
701 static int lzx_decompress_block(int block_type, int block_size, u8 *window,
703 const struct lzx_tables *tables,
704 struct lru_queue *queue,
705 struct input_bitstream *istream)
707 uint bytes_remaining;
712 bytes_remaining = block_size;
713 while (bytes_remaining > 0) {
715 ret = read_huffsym_using_maintree(istream, tables,
720 if (main_element < LZX_NUM_CHARS) {
721 /* literal: 0 to LZX_NUM_CHARS - 1 */
722 window[window_pos + block_size - bytes_remaining] =
726 /* match: LZX_NUM_CHARS to LZX_MAINTREE_NUM_SYMBOLS - 1 */
727 match_len = lzx_decode_match(main_element,
728 block_type, bytes_remaining, window,
729 block_size + window_pos -
731 tables, queue, istream);
735 bytes_remaining -= match_len;
742 * Decompresses a block of LZX-compressed data using a window size of 32768.
744 * @compressed_data: A pointer to the compressed data.
745 * @compressed_len: The length of the compressed data, in bytes.
746 * @uncompressed_data: A pointer to the buffer into which to write the
748 * @uncompressed_len: The length of the uncompressed data.
750 * Return non-zero on failure.
752 int lzx_decompress(const void *compressed_data, uint compressed_len,
753 void *uncompressed_data, uint uncompressed_len)
755 struct lzx_tables tables;
756 struct input_bitstream istream;
757 struct lru_queue queue;
758 uint bytes_remaining;
763 LZX_DEBUG("lzx_decompress (compressed_data = %p, compressed_len = %d, "
764 "uncompressed_data = %p, uncompressed_len = %d).",
765 compressed_data, compressed_len,
766 uncompressed_data, uncompressed_len);
768 wimlib_assert(uncompressed_len <= 32768);
770 memset(tables.maintree_lens, 0, sizeof(tables.maintree_lens));
771 memset(tables.lentree_lens, 0, sizeof(tables.lentree_lens));
775 bytes_remaining = uncompressed_len;
777 init_input_bitstream(&istream, compressed_data, compressed_len);
779 /* The compressed data will consist of one or more blocks. The
780 * following loop decompresses one block, and it runs until there all
781 * the compressed data has been decompressed, so there are no more
784 while (bytes_remaining != 0) {
786 LZX_DEBUG("Reading block header.");
787 ret = lzx_read_block_header(&istream, &block_size, &block_type,
792 LZX_DEBUG("block_size = %d, bytes_remaining = %d.",
793 block_size, bytes_remaining);
795 if (block_size > bytes_remaining) {
796 ERROR("lzx_decompress(): Expected a block size of at "
797 "most %d bytes (found %d bytes)",
798 bytes_remaining, block_size);
802 switch (block_type) {
803 case LZX_BLOCKTYPE_VERBATIM:
804 case LZX_BLOCKTYPE_ALIGNED:
805 if (block_type == LZX_BLOCKTYPE_VERBATIM)
806 LZX_DEBUG("LZX_BLOCKTYPE_VERBATIM");
808 LZX_DEBUG("LZX_BLOCKTYPE_ALIGNED");
810 ret = lzx_decompress_block(block_type,
815 &tables, &queue, &istream);
819 case LZX_BLOCKTYPE_UNCOMPRESSED:
820 LZX_DEBUG("LZX_BLOCKTYPE_UNCOMPRESSED");
821 ret = bitstream_read_bytes(&istream, block_size,
828 align_input_bitstream(&istream, false);
835 bytes_remaining -= block_size;
837 if (bytes_remaining != 0)
838 LZX_DEBUG("%d bytes remaining.", bytes_remaining);
842 if (uncompressed_len >= 10)
843 undo_call_insn_preprocessing(uncompressed_data,