[PATCH 04/16] use kernel bunzip implementation
Sascha Hauer
s.hauer at pengutronix.de
Mon Nov 28 17:09:57 EST 2011
The kernel uncompression functions have a unified API. Switch
to the kernel implementation to unify the different uncompression
APIs. As a bonus the kernel implementation is much smaller.
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
commands/bootm.c | 23 +-
include/bunzip2.h | 10 +
lib/Makefile | 2 +-
lib/decompress_bunzip2.c | 756 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 779 insertions(+), 12 deletions(-)
create mode 100644 include/bunzip2.h
create mode 100644 lib/decompress_bunzip2.c
diff --git a/commands/bootm.c b/commands/bootm.c
index 731b74d..22b4964 100644
--- a/commands/bootm.c
+++ b/commands/bootm.c
@@ -31,7 +31,6 @@
#include <image.h>
#include <malloc.h>
#include <zlib.h>
-#include <bzlib.h>
#include <environment.h>
#include <asm/byteorder.h>
#include <xfuncs.h>
@@ -42,6 +41,7 @@
#include <boot.h>
#include <rtc.h>
#include <init.h>
+#include <bunzip2.h>
#include <asm-generic/memory_layout.h>
/*
@@ -103,12 +103,18 @@ struct image_handle_data* image_handle_data_get_by_num(struct image_handle* hand
return &handle->data_entries[num];
}
+static void unzip_error(char *x)
+{
+ puts(x);
+}
+
int relocate_image(struct image_handle *handle, void *load_address)
{
image_header_t *hdr = &handle->header;
unsigned long len = image_get_size(hdr);
struct image_handle_data *iha;
unsigned long data;
+ int ret;
#if defined CONFIG_CMD_BOOTM_ZLIB || defined CONFIG_CMD_BOOTM_BZLIB
uint unc_len = CFG_BOOTM_LEN;
@@ -136,16 +142,11 @@ int relocate_image(struct image_handle *handle, void *load_address)
#ifdef CONFIG_CMD_BOOTM_BZLIB
case IH_COMP_BZIP2:
printf (" Uncompressing ... ");
- /*
- * If we've got less than 4 MB of malloc() space,
- * use slower decompression algorithm which requires
- * at most 2300 KB of memory.
- */
- if (BZ2_bzBuffToBuffDecompress (load_address,
- &unc_len, (char *)data, len,
- MALLOC_SIZE < (4096 * 1024), 0)
- != BZ_OK)
- return -1;
+
+ ret = bunzip2((void *)data, len, NULL, NULL, load_address, NULL,
+ unzip_error);
+ if (ret)
+ return ret;
break;
#endif
default:
diff --git a/include/bunzip2.h b/include/bunzip2.h
new file mode 100644
index 0000000..1152721
--- /dev/null
+++ b/include/bunzip2.h
@@ -0,0 +1,10 @@
+#ifndef DECOMPRESS_BUNZIP2_H
+#define DECOMPRESS_BUNZIP2_H
+
+int bunzip2(unsigned char *inbuf, int len,
+ int(*fill)(void*, unsigned int),
+ int(*flush)(void*, unsigned int),
+ unsigned char *output,
+ int *pos,
+ void(*error)(char *x));
+#endif
diff --git a/lib/Makefile b/lib/Makefile
index eccdfff..b02191a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -15,7 +15,7 @@ obj-y += libgen.o
obj-y += stringlist.o
obj-y += recursive_action.o
obj-y += make_directory.o
-obj-$(CONFIG_BZLIB) += bzlib.o bzlib_crctable.o bzlib_decompress.o bzlib_huffman.o bzlib_randtable.o
+obj-$(CONFIG_BZLIB) += decompress_bunzip2.o
obj-$(CONFIG_ZLIB) += zlib.o gunzip.o
obj-$(CONFIG_CMDLINE_EDITING) += readline.o
obj-$(CONFIG_SIMPLE_READLINE) += readline_simple.o
diff --git a/lib/decompress_bunzip2.c b/lib/decompress_bunzip2.c
new file mode 100644
index 0000000..4b6edd1
--- /dev/null
+++ b/lib/decompress_bunzip2.c
@@ -0,0 +1,756 @@
+/* vi: set sw = 4 ts = 4: */
+/* Small bzip2 deflate implementation, by Rob Landley (rob at landley.net).
+
+ Based on bzip2 decompression code by Julian R Seward (jseward at acm.org),
+ which also acknowledges contributions by Mike Burrows, David Wheeler,
+ Peter Fenwick, Alistair Moffat, Radford Neal, Ian H. Witten,
+ Robert Sedgewick, and Jon L. Bentley.
+
+ This code is licensed under the LGPLv2:
+ LGPL (http://www.gnu.org/copyleft/lgpl.html
+*/
+
+/*
+ Size and speed optimizations by Manuel Novoa III (mjn3 at codepoet.org).
+
+ More efficient reading of Huffman codes, a streamlined read_bunzip()
+ function, and various other tweaks. In (limited) tests, approximately
+ 20% faster than bzcat on x86 and about 10% faster on arm.
+
+ Note that about 2/3 of the time is spent in read_unzip() reversing
+ the Burrows-Wheeler transformation. Much of that time is delay
+ resulting from cache misses.
+
+ I would ask that anyone benefiting from this work, especially those
+ using it in commercial products, consider making a donation to my local
+ non-profit hospice organization in the name of the woman I loved, who
+ passed away Feb. 12, 2003.
+
+ In memory of Toni W. Hagan
+
+ Hospice of Acadiana, Inc.
+ 2600 Johnston St., Suite 200
+ Lafayette, LA 70503-3240
+
+ Phone (337) 232-1234 or 1-800-738-2226
+ Fax (337) 232-1297
+
+ http://www.hospiceacadiana.com/
+
+ Manuel
+ */
+
+/*
+ Made it fit for running in Linux Kernel by Alain Knaff (alain at knaff.lu)
+*/
+
+#include <common.h>
+#include <malloc.h>
+
+#ifdef STATIC
+#define PREBOOT
+#else
+#include <bunzip2.h>
+#endif /* STATIC */
+
+#ifndef INT_MAX
+#define INT_MAX 0x7fffffff
+#endif
+
+/* Constants for Huffman coding */
+#define MAX_GROUPS 6
+#define GROUP_SIZE 50 /* 64 would have been more efficient */
+#define MAX_HUFCODE_BITS 20 /* Longest Huffman code allowed */
+#define MAX_SYMBOLS 258 /* 256 literals + RUNA + RUNB */
+#define SYMBOL_RUNA 0
+#define SYMBOL_RUNB 1
+
+/* Status return values */
+#define RETVAL_OK 0
+#define RETVAL_LAST_BLOCK (-1)
+#define RETVAL_NOT_BZIP_DATA (-2)
+#define RETVAL_UNEXPECTED_INPUT_EOF (-3)
+#define RETVAL_UNEXPECTED_OUTPUT_EOF (-4)
+#define RETVAL_DATA_ERROR (-5)
+#define RETVAL_OUT_OF_MEMORY (-6)
+#define RETVAL_OBSOLETE_INPUT (-7)
+
+/* Other housekeeping constants */
+#define BZIP2_IOBUF_SIZE 4096
+
+/* This is what we know about each Huffman coding group */
+struct group_data {
+ /* We have an extra slot at the end of limit[] for a sentinal value. */
+ int limit[MAX_HUFCODE_BITS+1];
+ int base[MAX_HUFCODE_BITS];
+ int permute[MAX_SYMBOLS];
+ int minLen, maxLen;
+};
+
+/* Structure holding all the housekeeping data, including IO buffers and
+ memory that persists between calls to bunzip */
+struct bunzip_data {
+ /* State for interrupting output loop */
+ int writeCopies, writePos, writeRunCountdown, writeCount, writeCurrent;
+ /* I/O tracking data (file handles, buffers, positions, etc.) */
+ int (*fill)(void*, unsigned int);
+ int inbufCount, inbufPos /*, outbufPos*/;
+ unsigned char *inbuf /*,*outbuf*/;
+ unsigned int inbufBitCount, inbufBits;
+ /* The CRC values stored in the block header and calculated from the
+ data */
+ unsigned int crc32Table[256], headerCRC, totalCRC, writeCRC;
+ /* Intermediate buffer and its size (in bytes) */
+ unsigned int *dbuf, dbufSize;
+ /* These things are a bit too big to go on the stack */
+ unsigned char selectors[32768]; /* nSelectors = 15 bits */
+ struct group_data groups[MAX_GROUPS]; /* Huffman coding tables */
+ int io_error; /* non-zero if we have IO error */
+ int byteCount[256];
+ unsigned char symToByte[256], mtfSymbol[256];
+};
+
+
+/* Return the next nnn bits of input. All reads from the compressed input
+ are done through this function. All reads are big endian */
+static unsigned int get_bits(struct bunzip_data *bd, char bits_wanted)
+{
+ unsigned int bits = 0;
+
+ /* If we need to get more data from the byte buffer, do so.
+ (Loop getting one byte at a time to enforce endianness and avoid
+ unaligned access.) */
+ while (bd->inbufBitCount < bits_wanted) {
+ /* If we need to read more data from file into byte buffer, do
+ so */
+ if (bd->inbufPos == bd->inbufCount) {
+ if (bd->io_error)
+ return 0;
+ bd->inbufCount = bd->fill(bd->inbuf, BZIP2_IOBUF_SIZE);
+ if (bd->inbufCount <= 0) {
+ bd->io_error = RETVAL_UNEXPECTED_INPUT_EOF;
+ return 0;
+ }
+ bd->inbufPos = 0;
+ }
+ /* Avoid 32-bit overflow (dump bit buffer to top of output) */
+ if (bd->inbufBitCount >= 24) {
+ bits = bd->inbufBits&((1 << bd->inbufBitCount)-1);
+ bits_wanted -= bd->inbufBitCount;
+ bits <<= bits_wanted;
+ bd->inbufBitCount = 0;
+ }
+ /* Grab next 8 bits of input from buffer. */
+ bd->inbufBits = (bd->inbufBits << 8)|bd->inbuf[bd->inbufPos++];
+ bd->inbufBitCount += 8;
+ }
+ /* Calculate result */
+ bd->inbufBitCount -= bits_wanted;
+ bits |= (bd->inbufBits >> bd->inbufBitCount)&((1 << bits_wanted)-1);
+
+ return bits;
+}
+
+/* Unpacks the next block and sets up for the inverse burrows-wheeler step. */
+
+static int get_next_block(struct bunzip_data *bd)
+{
+ struct group_data *hufGroup = NULL;
+ int *base = NULL;
+ int *limit = NULL;
+ int dbufCount, nextSym, dbufSize, groupCount, selector,
+ i, j, k, t, runPos, symCount, symTotal, nSelectors, *byteCount;
+ unsigned char uc, *symToByte, *mtfSymbol, *selectors;
+ unsigned int *dbuf, origPtr;
+
+ dbuf = bd->dbuf;
+ dbufSize = bd->dbufSize;
+ selectors = bd->selectors;
+ byteCount = bd->byteCount;
+ symToByte = bd->symToByte;
+ mtfSymbol = bd->mtfSymbol;
+
+ /* Read in header signature and CRC, then validate signature.
+ (last block signature means CRC is for whole file, return now) */
+ i = get_bits(bd, 24);
+ j = get_bits(bd, 24);
+ bd->headerCRC = get_bits(bd, 32);
+ if ((i == 0x177245) && (j == 0x385090))
+ return RETVAL_LAST_BLOCK;
+ if ((i != 0x314159) || (j != 0x265359))
+ return RETVAL_NOT_BZIP_DATA;
+ /* We can add support for blockRandomised if anybody complains.
+ There was some code for this in busybox 1.0.0-pre3, but nobody ever
+ noticed that it didn't actually work. */
+ if (get_bits(bd, 1))
+ return RETVAL_OBSOLETE_INPUT;
+ origPtr = get_bits(bd, 24);
+ if (origPtr > dbufSize)
+ return RETVAL_DATA_ERROR;
+ /* mapping table: if some byte values are never used (encoding things
+ like ascii text), the compression code removes the gaps to have fewer
+ symbols to deal with, and writes a sparse bitfield indicating which
+ values were present. We make a translation table to convert the
+ symbols back to the corresponding bytes. */
+ t = get_bits(bd, 16);
+ symTotal = 0;
+ for (i = 0; i < 16; i++) {
+ if (t&(1 << (15-i))) {
+ k = get_bits(bd, 16);
+ for (j = 0; j < 16; j++)
+ if (k&(1 << (15-j)))
+ symToByte[symTotal++] = (16*i)+j;
+ }
+ }
+ /* How many different Huffman coding groups does this block use? */
+ groupCount = get_bits(bd, 3);
+ if (groupCount < 2 || groupCount > MAX_GROUPS)
+ return RETVAL_DATA_ERROR;
+ /* nSelectors: Every GROUP_SIZE many symbols we select a new
+ Huffman coding group. Read in the group selector list,
+ which is stored as MTF encoded bit runs. (MTF = Move To
+ Front, as each value is used it's moved to the start of the
+ list.) */
+ nSelectors = get_bits(bd, 15);
+ if (!nSelectors)
+ return RETVAL_DATA_ERROR;
+ for (i = 0; i < groupCount; i++)
+ mtfSymbol[i] = i;
+ for (i = 0; i < nSelectors; i++) {
+ /* Get next value */
+ for (j = 0; get_bits(bd, 1); j++)
+ if (j >= groupCount)
+ return RETVAL_DATA_ERROR;
+ /* Decode MTF to get the next selector */
+ uc = mtfSymbol[j];
+ for (; j; j--)
+ mtfSymbol[j] = mtfSymbol[j-1];
+ mtfSymbol[0] = selectors[i] = uc;
+ }
+ /* Read the Huffman coding tables for each group, which code
+ for symTotal literal symbols, plus two run symbols (RUNA,
+ RUNB) */
+ symCount = symTotal+2;
+ for (j = 0; j < groupCount; j++) {
+ unsigned char length[MAX_SYMBOLS], temp[MAX_HUFCODE_BITS+1];
+ int minLen, maxLen, pp;
+ /* Read Huffman code lengths for each symbol. They're
+ stored in a way similar to mtf; record a starting
+ value for the first symbol, and an offset from the
+ previous value for everys symbol after that.
+ (Subtracting 1 before the loop and then adding it
+ back at the end is an optimization that makes the
+ test inside the loop simpler: symbol length 0
+ becomes negative, so an unsigned inequality catches
+ it.) */
+ t = get_bits(bd, 5)-1;
+ for (i = 0; i < symCount; i++) {
+ for (;;) {
+ if (((unsigned)t) > (MAX_HUFCODE_BITS-1))
+ return RETVAL_DATA_ERROR;
+
+ /* If first bit is 0, stop. Else
+ second bit indicates whether to
+ increment or decrement the value.
+ Optimization: grab 2 bits and unget
+ the second if the first was 0. */
+
+ k = get_bits(bd, 2);
+ if (k < 2) {
+ bd->inbufBitCount++;
+ break;
+ }
+ /* Add one if second bit 1, else
+ * subtract 1. Avoids if/else */
+ t += (((k+1)&2)-1);
+ }
+ /* Correct for the initial -1, to get the
+ * final symbol length */
+ length[i] = t+1;
+ }
+ /* Find largest and smallest lengths in this group */
+ minLen = maxLen = length[0];
+
+ for (i = 1; i < symCount; i++) {
+ if (length[i] > maxLen)
+ maxLen = length[i];
+ else if (length[i] < minLen)
+ minLen = length[i];
+ }
+
+ /* Calculate permute[], base[], and limit[] tables from
+ * length[].
+ *
+ * permute[] is the lookup table for converting
+ * Huffman coded symbols into decoded symbols. base[]
+ * is the amount to subtract from the value of a
+ * Huffman symbol of a given length when using
+ * permute[].
+ *
+ * limit[] indicates the largest numerical value a
+ * symbol with a given number of bits can have. This
+ * is how the Huffman codes can vary in length: each
+ * code with a value > limit[length] needs another
+ * bit.
+ */
+ hufGroup = bd->groups+j;
+ hufGroup->minLen = minLen;
+ hufGroup->maxLen = maxLen;
+ /* Note that minLen can't be smaller than 1, so we
+ adjust the base and limit array pointers so we're
+ not always wasting the first entry. We do this
+ again when using them (during symbol decoding).*/
+ base = hufGroup->base-1;
+ limit = hufGroup->limit-1;
+ /* Calculate permute[]. Concurrently, initialize
+ * temp[] and limit[]. */
+ pp = 0;
+ for (i = minLen; i <= maxLen; i++) {
+ temp[i] = limit[i] = 0;
+ for (t = 0; t < symCount; t++)
+ if (length[t] == i)
+ hufGroup->permute[pp++] = t;
+ }
+ /* Count symbols coded for at each bit length */
+ for (i = 0; i < symCount; i++)
+ temp[length[i]]++;
+ /* Calculate limit[] (the largest symbol-coding value
+ *at each bit length, which is (previous limit <<
+ *1)+symbols at this level), and base[] (number of
+ *symbols to ignore at each bit length, which is limit
+ *minus the cumulative count of symbols coded for
+ *already). */
+ pp = t = 0;
+ for (i = minLen; i < maxLen; i++) {
+ pp += temp[i];
+ /* We read the largest possible symbol size
+ and then unget bits after determining how
+ many we need, and those extra bits could be
+ set to anything. (They're noise from
+ future symbols.) At each level we're
+ really only interested in the first few
+ bits, so here we set all the trailing
+ to-be-ignored bits to 1 so they don't
+ affect the value > limit[length]
+ comparison. */
+ limit[i] = (pp << (maxLen - i)) - 1;
+ pp <<= 1;
+ base[i+1] = pp-(t += temp[i]);
+ }
+ limit[maxLen+1] = INT_MAX; /* Sentinal value for
+ * reading next sym. */
+ limit[maxLen] = pp+temp[maxLen]-1;
+ base[minLen] = 0;
+ }
+ /* We've finished reading and digesting the block header. Now
+ read this block's Huffman coded symbols from the file and
+ undo the Huffman coding and run length encoding, saving the
+ result into dbuf[dbufCount++] = uc */
+
+ /* Initialize symbol occurrence counters and symbol Move To
+ * Front table */
+ for (i = 0; i < 256; i++) {
+ byteCount[i] = 0;
+ mtfSymbol[i] = (unsigned char)i;
+ }
+ /* Loop through compressed symbols. */
+ runPos = dbufCount = symCount = selector = 0;
+ for (;;) {
+ /* Determine which Huffman coding group to use. */
+ if (!(symCount--)) {
+ symCount = GROUP_SIZE-1;
+ if (selector >= nSelectors)
+ return RETVAL_DATA_ERROR;
+ hufGroup = bd->groups+selectors[selector++];
+ base = hufGroup->base-1;
+ limit = hufGroup->limit-1;
+ }
+ /* Read next Huffman-coded symbol. */
+ /* Note: It is far cheaper to read maxLen bits and
+ back up than it is to read minLen bits and then an
+ additional bit at a time, testing as we go.
+ Because there is a trailing last block (with file
+ CRC), there is no danger of the overread causing an
+ unexpected EOF for a valid compressed file. As a
+ further optimization, we do the read inline
+ (falling back to a call to get_bits if the buffer
+ runs dry). The following (up to got_huff_bits:) is
+ equivalent to j = get_bits(bd, hufGroup->maxLen);
+ */
+ while (bd->inbufBitCount < hufGroup->maxLen) {
+ if (bd->inbufPos == bd->inbufCount) {
+ j = get_bits(bd, hufGroup->maxLen);
+ goto got_huff_bits;
+ }
+ bd->inbufBits =
+ (bd->inbufBits << 8)|bd->inbuf[bd->inbufPos++];
+ bd->inbufBitCount += 8;
+ };
+ bd->inbufBitCount -= hufGroup->maxLen;
+ j = (bd->inbufBits >> bd->inbufBitCount)&
+ ((1 << hufGroup->maxLen)-1);
+got_huff_bits:
+ /* Figure how how many bits are in next symbol and
+ * unget extras */
+ i = hufGroup->minLen;
+ while (j > limit[i])
+ ++i;
+ bd->inbufBitCount += (hufGroup->maxLen - i);
+ /* Huffman decode value to get nextSym (with bounds checking) */
+ if ((i > hufGroup->maxLen)
+ || (((unsigned)(j = (j>>(hufGroup->maxLen-i))-base[i]))
+ >= MAX_SYMBOLS))
+ return RETVAL_DATA_ERROR;
+ nextSym = hufGroup->permute[j];
+ /* We have now decoded the symbol, which indicates
+ either a new literal byte, or a repeated run of the
+ most recent literal byte. First, check if nextSym
+ indicates a repeated run, and if so loop collecting
+ how many times to repeat the last literal. */
+ if (((unsigned)nextSym) <= SYMBOL_RUNB) { /* RUNA or RUNB */
+ /* If this is the start of a new run, zero out
+ * counter */
+ if (!runPos) {
+ runPos = 1;
+ t = 0;
+ }
+ /* Neat trick that saves 1 symbol: instead of
+ or-ing 0 or 1 at each bit position, add 1
+ or 2 instead. For example, 1011 is 1 << 0
+ + 1 << 1 + 2 << 2. 1010 is 2 << 0 + 2 << 1
+ + 1 << 2. You can make any bit pattern
+ that way using 1 less symbol than the basic
+ or 0/1 method (except all bits 0, which
+ would use no symbols, but a run of length 0
+ doesn't mean anything in this context).
+ Thus space is saved. */
+ t += (runPos << nextSym);
+ /* +runPos if RUNA; +2*runPos if RUNB */
+
+ runPos <<= 1;
+ continue;
+ }
+ /* When we hit the first non-run symbol after a run,
+ we now know how many times to repeat the last
+ literal, so append that many copies to our buffer
+ of decoded symbols (dbuf) now. (The last literal
+ used is the one at the head of the mtfSymbol
+ array.) */
+ if (runPos) {
+ runPos = 0;
+ if (dbufCount+t >= dbufSize)
+ return RETVAL_DATA_ERROR;
+
+ uc = symToByte[mtfSymbol[0]];
+ byteCount[uc] += t;
+ while (t--)
+ dbuf[dbufCount++] = uc;
+ }
+ /* Is this the terminating symbol? */
+ if (nextSym > symTotal)
+ break;
+ /* At this point, nextSym indicates a new literal
+ character. Subtract one to get the position in the
+ MTF array at which this literal is currently to be
+ found. (Note that the result can't be -1 or 0,
+ because 0 and 1 are RUNA and RUNB. But another
+ instance of the first symbol in the mtf array,
+ position 0, would have been handled as part of a
+ run above. Therefore 1 unused mtf position minus 2
+ non-literal nextSym values equals -1.) */
+ if (dbufCount >= dbufSize)
+ return RETVAL_DATA_ERROR;
+ i = nextSym - 1;
+ uc = mtfSymbol[i];
+ /* Adjust the MTF array. Since we typically expect to
+ *move only a small number of symbols, and are bound
+ *by 256 in any case, using memmove here would
+ *typically be bigger and slower due to function call
+ *overhead and other assorted setup costs. */
+ do {
+ mtfSymbol[i] = mtfSymbol[i-1];
+ } while (--i);
+ mtfSymbol[0] = uc;
+ uc = symToByte[uc];
+ /* We have our literal byte. Save it into dbuf. */
+ byteCount[uc]++;
+ dbuf[dbufCount++] = (unsigned int)uc;
+ }
+ /* At this point, we've read all the Huffman-coded symbols
+ (and repeated runs) for this block from the input stream,
+ and decoded them into the intermediate buffer. There are
+ dbufCount many decoded bytes in dbuf[]. Now undo the
+ Burrows-Wheeler transform on dbuf. See
+ http://dogma.net/markn/articles/bwt/bwt.htm
+ */
+ /* Turn byteCount into cumulative occurrence counts of 0 to n-1. */
+ j = 0;
+ for (i = 0; i < 256; i++) {
+ k = j+byteCount[i];
+ byteCount[i] = j;
+ j = k;
+ }
+ /* Figure out what order dbuf would be in if we sorted it. */
+ for (i = 0; i < dbufCount; i++) {
+ uc = (unsigned char)(dbuf[i] & 0xff);
+ dbuf[byteCount[uc]] |= (i << 8);
+ byteCount[uc]++;
+ }
+ /* Decode first byte by hand to initialize "previous" byte.
+ Note that it doesn't get output, and if the first three
+ characters are identical it doesn't qualify as a run (hence
+ writeRunCountdown = 5). */
+ if (dbufCount) {
+ if (origPtr >= dbufCount)
+ return RETVAL_DATA_ERROR;
+ bd->writePos = dbuf[origPtr];
+ bd->writeCurrent = (unsigned char)(bd->writePos&0xff);
+ bd->writePos >>= 8;
+ bd->writeRunCountdown = 5;
+ }
+ bd->writeCount = dbufCount;
+
+ return RETVAL_OK;
+}
+
+/* Undo burrows-wheeler transform on intermediate buffer to produce output.
+ If start_bunzip was initialized with out_fd =-1, then up to len bytes of
+ data are written to outbuf. Return value is number of bytes written or
+ error (all errors are negative numbers). If out_fd!=-1, outbuf and len
+ are ignored, data is written to out_fd and return is RETVAL_OK or error.
+*/
+
+static int read_bunzip(struct bunzip_data *bd, char *outbuf, int len)
+{
+ const unsigned int *dbuf;
+ int pos, xcurrent, previous, gotcount;
+
+ /* If last read was short due to end of file, return last block now */
+ if (bd->writeCount < 0)
+ return bd->writeCount;
+
+ gotcount = 0;
+ dbuf = bd->dbuf;
+ pos = bd->writePos;
+ xcurrent = bd->writeCurrent;
+
+ /* We will always have pending decoded data to write into the output
+ buffer unless this is the very first call (in which case we haven't
+ Huffman-decoded a block into the intermediate buffer yet). */
+
+ if (bd->writeCopies) {
+ /* Inside the loop, writeCopies means extra copies (beyond 1) */
+ --bd->writeCopies;
+ /* Loop outputting bytes */
+ for (;;) {
+ /* If the output buffer is full, snapshot
+ * state and return */
+ if (gotcount >= len) {
+ bd->writePos = pos;
+ bd->writeCurrent = xcurrent;
+ bd->writeCopies++;
+ return len;
+ }
+ /* Write next byte into output buffer, updating CRC */
+ outbuf[gotcount++] = xcurrent;
+ bd->writeCRC = (((bd->writeCRC) << 8)
+ ^bd->crc32Table[((bd->writeCRC) >> 24)
+ ^xcurrent]);
+ /* Loop now if we're outputting multiple
+ * copies of this byte */
+ if (bd->writeCopies) {
+ --bd->writeCopies;
+ continue;
+ }
+decode_next_byte:
+ if (!bd->writeCount--)
+ break;
+ /* Follow sequence vector to undo
+ * Burrows-Wheeler transform */
+ previous = xcurrent;
+ pos = dbuf[pos];
+ xcurrent = pos&0xff;
+ pos >>= 8;
+ /* After 3 consecutive copies of the same
+ byte, the 4th is a repeat count. We count
+ down from 4 instead *of counting up because
+ testing for non-zero is faster */
+ if (--bd->writeRunCountdown) {
+ if (xcurrent != previous)
+ bd->writeRunCountdown = 4;
+ } else {
+ /* We have a repeated run, this byte
+ * indicates the count */
+ bd->writeCopies = xcurrent;
+ xcurrent = previous;
+ bd->writeRunCountdown = 5;
+ /* Sometimes there are just 3 bytes
+ * (run length 0) */
+ if (!bd->writeCopies)
+ goto decode_next_byte;
+ /* Subtract the 1 copy we'd output
+ * anyway to get extras */
+ --bd->writeCopies;
+ }
+ }
+ /* Decompression of this block completed successfully */
+ bd->writeCRC = ~bd->writeCRC;
+ bd->totalCRC = ((bd->totalCRC << 1) |
+ (bd->totalCRC >> 31)) ^ bd->writeCRC;
+ /* If this block had a CRC error, force file level CRC error. */
+ if (bd->writeCRC != bd->headerCRC) {
+ bd->totalCRC = bd->headerCRC+1;
+ return RETVAL_LAST_BLOCK;
+ }
+ }
+
+ /* Refill the intermediate buffer by Huffman-decoding next
+ * block of input */
+ /* (previous is just a convenient unused temp variable here) */
+ previous = get_next_block(bd);
+ if (previous) {
+ bd->writeCount = previous;
+ return (previous != RETVAL_LAST_BLOCK) ? previous : gotcount;
+ }
+ bd->writeCRC = 0xffffffffUL;
+ pos = bd->writePos;
+ xcurrent = bd->writeCurrent;
+ goto decode_next_byte;
+}
+
+static int nofill(void *buf, unsigned int len)
+{
+ return -1;
+}
+
+/* Allocate the structure, read file header. If in_fd ==-1, inbuf must contain
+ a complete bunzip file (len bytes long). If in_fd!=-1, inbuf and len are
+ ignored, and data is read from file handle into temporary buffer. */
+static int start_bunzip(struct bunzip_data **bdp, void *inbuf, int len,
+ int (*fill)(void*, unsigned int))
+{
+ struct bunzip_data *bd;
+ unsigned int i, j, c;
+ const unsigned int BZh0 =
+ (((unsigned int)'B') << 24)+(((unsigned int)'Z') << 16)
+ +(((unsigned int)'h') << 8)+(unsigned int)'0';
+
+ /* Figure out how much data to allocate */
+ i = sizeof(struct bunzip_data);
+
+ /* Allocate bunzip_data. Most fields initialize to zero. */
+ bd = *bdp = malloc(i);
+ if (!bd)
+ return RETVAL_OUT_OF_MEMORY;
+ memset(bd, 0, sizeof(struct bunzip_data));
+ /* Setup input buffer */
+ bd->inbuf = inbuf;
+ bd->inbufCount = len;
+ if (fill != NULL)
+ bd->fill = fill;
+ else
+ bd->fill = nofill;
+
+ /* Init the CRC32 table (big endian) */
+ for (i = 0; i < 256; i++) {
+ c = i << 24;
+ for (j = 8; j; j--)
+ c = c&0x80000000 ? (c << 1)^0x04c11db7 : (c << 1);
+ bd->crc32Table[i] = c;
+ }
+
+ /* Ensure that file starts with "BZh['1'-'9']." */
+ i = get_bits(bd, 32);
+ if (((unsigned int)(i-BZh0-1)) >= 9)
+ return RETVAL_NOT_BZIP_DATA;
+
+ /* Fourth byte (ascii '1'-'9'), indicates block size in units of 100k of
+ uncompressed data. Allocate intermediate buffer for block. */
+ bd->dbufSize = 100000*(i-BZh0);
+
+ bd->dbuf = malloc(bd->dbufSize * sizeof(int));
+ if (!bd->dbuf)
+ return RETVAL_OUT_OF_MEMORY;
+ return RETVAL_OK;
+}
+
+/* Example usage: decompress src_fd to dst_fd. (Stops at end of bzip2 data,
+ not end of file.) */
+int bunzip2(unsigned char *buf, int len,
+ int(*fill)(void*, unsigned int),
+ int(*flush)(void*, unsigned int),
+ unsigned char *outbuf,
+ int *pos,
+ void(*error)(char *x))
+{
+ struct bunzip_data *bd;
+ int i = -1;
+ unsigned char *inbuf;
+
+ if (flush)
+ outbuf = malloc(BZIP2_IOBUF_SIZE);
+
+ if (!outbuf) {
+ error("Could not allocate output bufer");
+ return RETVAL_OUT_OF_MEMORY;
+ }
+ if (buf)
+ inbuf = buf;
+ else
+ inbuf = malloc(BZIP2_IOBUF_SIZE);
+ if (!inbuf) {
+ error("Could not allocate input bufer");
+ i = RETVAL_OUT_OF_MEMORY;
+ goto exit_0;
+ }
+ i = start_bunzip(&bd, inbuf, len, fill);
+ if (!i) {
+ for (;;) {
+ i = read_bunzip(bd, outbuf, BZIP2_IOBUF_SIZE);
+ if (i <= 0)
+ break;
+ if (!flush)
+ outbuf += i;
+ else
+ if (i != flush(outbuf, i)) {
+ i = RETVAL_UNEXPECTED_OUTPUT_EOF;
+ break;
+ }
+ }
+ }
+ /* Check CRC and release memory */
+ if (i == RETVAL_LAST_BLOCK) {
+ if (bd->headerCRC != bd->totalCRC)
+ error("Data integrity error when decompressing.");
+ else
+ i = RETVAL_OK;
+ } else if (i == RETVAL_UNEXPECTED_OUTPUT_EOF) {
+ error("Compressed file ends unexpectedly");
+ }
+ if (!bd)
+ goto exit_1;
+ if (bd->dbuf)
+ free(bd->dbuf);
+ if (pos)
+ *pos = bd->inbufPos;
+ free(bd);
+exit_1:
+ if (!buf)
+ free(inbuf);
+exit_0:
+ if (flush)
+ free(outbuf);
+ return i;
+}
+
+#ifdef PREBOOT
+STATIC int INIT decompress(unsigned char *buf, int len,
+ int(*fill)(void*, unsigned int),
+ int(*flush)(void*, unsigned int),
+ unsigned char *outbuf,
+ int *pos,
+ void(*error)(char *x))
+{
+ return bunzip2(buf, len - 4, fill, flush, outbuf, pos, error);
+}
+#endif
--
1.7.7.1
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