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x86/dom0: support bzip2 and lzma compressed bzImage payloads

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This matches functionality in the tools already supporting the same
for DomU-s.

Code taken from Linux 2.6.32-rc and adjusted as little as possible to
be usable in Xen.

The question is whether, particularly for non-Linux Dom0-s, plain ELF
images compressed by bzip2 or lzma should also be supported.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
This commit is contained in:
Keir Fraser committed 2009-11-09 07:52:27 +00:00
1 parent 14ec087884
commit ab77e81f65
7 files changed
+1495 -16
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xen/arch/x86/bzimage.c
+36 -16
View File
@@ -4,6 +4,7 @@
#include <xen/mm.h>
#include <xen/string.h>
#include <xen/types.h>
#include <xen/decompress.h>
#include <asm/bzimage.h>
#define HEAPORDER 3
@@ -93,28 +94,38 @@ static __init void flush_window(void)
outcnt = 0;
}
static __init int gzip_length(char *image, unsigned long image_len)
static __init unsigned long output_length(char *image, unsigned long image_len)
{
return *(uint32_t *)&image[image_len - 4];
}
static __init int perform_gunzip(char *output, char **_image_start, unsigned long *image_len)
static __init int gzip_check(char *image, unsigned long image_len)
{
char *image = *_image_start;
int rc;
unsigned char magic0 = (unsigned char)image[0];
unsigned char magic1 = (unsigned char)image[1];
unsigned char magic0, magic1;
if ( magic0 != 0x1f || ( (magic1 != 0x8b) && (magic1 != 0x9e) ) )
if ( image_len < 2 )
return 0;
magic0 = (unsigned char)image[0];
magic1 = (unsigned char)image[1];
return (magic0 == 0x1f) && ((magic1 == 0x8b) || (magic1 == 0x9e));
}
static __init int perform_gunzip(char *output, char *image, unsigned long image_len)
{
int rc;
if ( !gzip_check(image, image_len) )
return 1;
window = (unsigned char *)output;
free_mem_ptr = (unsigned long)alloc_xenheap_pages(HEAPORDER, 0);
free_mem_end_ptr = free_mem_ptr + (PAGE_SIZE << HEAPORDER);
inbuf = (unsigned char *)image;
insize = *image_len;
insize = image_len;
inptr = 0;
makecrc();
@@ -125,8 +136,6 @@ static __init int perform_gunzip(char *output, char **_image_start, unsigned lo
}
else
{
*_image_start = (char *)window;
*image_len = gzip_length(image, *image_len);
rc = 0;
}
@@ -203,9 +212,12 @@ int __init bzimage_headroom(char *image_start, unsigned long image_length)
img = image_start + (hdr->setup_sects+1) * 512;
img += hdr->payload_offset;
headroom = gzip_length(img, hdr->payload_length);
headroom += headroom >> 12; /* Add 8 bytes for every 32K input block */
headroom += (32768 + 18); /* Add 32K + 18 bytes of extra headroom */
headroom = output_length(img, hdr->payload_length);
if (gzip_check(img, hdr->payload_length)) {
headroom += headroom >> 12; /* Add 8 bytes for every 32K input block */
headroom += (32768 + 18); /* Add 32K + 18 bytes of extra headroom */
} else
headroom += hdr->payload_length;
headroom = (headroom + 4095) & ~4095;
return headroom;
@@ -215,6 +227,7 @@ int __init bzimage_parse(char *image_base, char **image_start, unsigned long *im
{
struct setup_header *hdr = (struct setup_header *)(*image_start);
int err = bzimage_check(hdr, *image_len);
unsigned long output_len;
if (err < 1)
return err;
@@ -224,11 +237,18 @@ int __init bzimage_parse(char *image_base, char **image_start, unsigned long *im
*image_start += (hdr->setup_sects+1) * 512;
*image_start += hdr->payload_offset;
*image_len = hdr->payload_length;
output_len = output_length(*image_start, *image_len);
if ( (err = perform_gunzip(image_base, image_start, image_len)) < 0 )
return err;
if ( (err = perform_gunzip(image_base, *image_start, *image_len)) > 0 )
err = decompress(*image_start, *image_len, image_base);
return 0;
if ( !err )
{
*image_start = image_base;
*image_len = output_len;
}
return err > 0 ? 0 : err;
}
/*
xen/common/Makefile
+2
View File
@@ -35,6 +35,8 @@ obj-y += radix-tree.o
obj-y += rbtree.o
obj-y += lzo.o
obj-$(CONFIG_X86) += decompress.o bunzip2.o unlzma.o
obj-$(perfc) += perfc.o
obj-$(crash_debug) += gdbstub.o
obj-$(xenoprof) += xenoprof.o
xen/common/bunzip2.c
+726
View File
@@ -0,0 +1,726 @@
/* vi: set sw = 4 ts = 4: */
/* Small bzip2 deflate implementation, by Rob Landley (rob@landley.net).
Based on bzip2 decompression code by Julian R Seward (jseward@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@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@knaff.lu)
*/
#include "decompress.h"
#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 */
};
/* 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 INIT 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 INIT 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[256];
unsigned char uc, symToByte[256], mtfSymbol[256], *selectors;
unsigned int *dbuf, origPtr;
dbuf = bd->dbuf;
dbufSize = bd->dbufSize;
selectors = bd->selectors;
/* 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[]. Concurently, 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 INIT read_bunzip(struct bunzip_data *bd, unsigned 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 INIT 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 INIT 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);
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 = large_malloc(bd->dbufSize * sizeof(int));
return RETVAL_OK;
}
/* Example usage: decompress src_fd to dst_fd. (Stops at end of bzip2 data,
not end of file.) */
STATIC int INIT bunzip2(unsigned char *buf, unsigned int len,
int(*fill)(void*, unsigned int),
int(*flush)(void*, unsigned int),
unsigned char *outbuf,
unsigned int *pos,
void(*error_fn)(const char *x))
{
struct bunzip_data *bd;
int i = -1;
unsigned char *inbuf;
set_error_fn(error_fn);
if (flush)
outbuf = malloc(BZIP2_IOBUF_SIZE);
if (!outbuf) {
error("Could not allocate output bufer");
return -1;
}
if (buf)
inbuf = buf;
else
inbuf = malloc(BZIP2_IOBUF_SIZE);
if (!inbuf) {
error("Could not allocate input bufer");
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->dbuf)
large_free(bd->dbuf);
if (pos)
*pos = bd->inbufPos;
free(bd);
if (!buf)
free(inbuf);
exit_0:
if (flush)
free(outbuf);
return i;
}
xen/common/decompress.c
+27
View File
@@ -0,0 +1,27 @@
#include <xen/config.h>
#include <xen/init.h>
#include <xen/lib.h>
#include <xen/string.h>
#include <xen/decompress.h>
static void __init error(const char *msg)
{
printk("%s\n", msg);
}
int __init decompress(void *inbuf, unsigned int len, void *outbuf)
{
#if 0 /* Not needed here yet. */
if ( len >= 2 &&
(!memcmp(inbuf, "\037\213", 2) || !memcmp(inbuf, "\037\236", 2)) )
return gunzip(inbuf, len, NULL, NULL, outbuf, NULL, error);
#endif
if ( len >= 3 && !memcmp(inbuf, "\x42\x5a\x68", 3) )
return bunzip2(inbuf, len, NULL, NULL, outbuf, NULL, error);
if ( len >= 2 && !memcmp(inbuf, "\135\000", 2) )
return unlzma(inbuf, len, NULL, NULL, outbuf, NULL, error);
return 1;
}
xen/common/decompress.h
+19
View File
@@ -0,0 +1,19 @@
#include <xen/config.h>
#include <xen/cache.h>
#include <xen/decompress.h>
#include <xen/init.h>
#include <xen/string.h>
#include <xen/types.h>
#include <xen/xmalloc.h>
#define STATIC
#define INIT __init
static void(*__initdata error)(const char *);
#define set_error_fn(x) error = x;
#define malloc xmalloc_bytes
#define free xfree
#define large_malloc xmalloc_bytes
#define large_free xfree
xen/common/unlzma.c
+647
View File
@@ -0,0 +1,647 @@
/* Lzma decompressor for Linux kernel. Shamelessly snarfed
* from busybox 1.1.1
*
* Linux kernel adaptation
* Copyright (C) 2006 Alain < alain@knaff.lu >
*
* Based on small lzma deflate implementation/Small range coder
* implementation for lzma.
* Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org >
*
* Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
* Copyright (C) 1999-2005 Igor Pavlov
*
* Copyrights of the parts, see headers below.
*
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "decompress.h"
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
static long long INIT read_int(unsigned char *ptr, int size)
{
int i;
long long ret = 0;
for (i = 0; i < size; i++)
ret = (ret << 8) | ptr[size-i-1];
return ret;
}
#define ENDIAN_CONVERT(x) \
x = (typeof(x))read_int((unsigned char *)&x, sizeof(x))
/* Small range coder implementation for lzma.
* Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org >
*
* Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
* Copyright (c) 1999-2005 Igor Pavlov
*/
#include <xen/compiler.h>
#define LZMA_IOBUF_SIZE 0x10000
struct rc {
int (*fill)(void*, unsigned int);
uint8_t *ptr;
uint8_t *buffer;
uint8_t *buffer_end;
int buffer_size;
uint32_t code;
uint32_t range;
uint32_t bound;
};
#define RC_TOP_BITS 24
#define RC_MOVE_BITS 5
#define RC_MODEL_TOTAL_BITS 11
static int nofill(void *buffer, unsigned int len)
{
return -1;
}
/* Called twice: once at startup and once in rc_normalize() */
static void INIT rc_read(struct rc *rc)
{
rc->buffer_size = rc->fill((char *)rc->buffer, LZMA_IOBUF_SIZE);
if (rc->buffer_size <= 0)
error("unexpected EOF");
rc->ptr = rc->buffer;
rc->buffer_end = rc->buffer + rc->buffer_size;
}
/* Called once */
static inline void INIT rc_init(struct rc *rc,
int (*fill)(void*, unsigned int),
unsigned char *buffer, int buffer_size)
{
if (fill)
rc->fill = fill;
else
rc->fill = nofill;
rc->buffer = (uint8_t *)buffer;
rc->buffer_size = buffer_size;
rc->buffer_end = rc->buffer + rc->buffer_size;
rc->ptr = rc->buffer;
rc->code = 0;
rc->range = 0xFFFFFFFF;
}
static inline void INIT rc_init_code(struct rc *rc)
{
int i;
for (i = 0; i < 5; i++) {
if (rc->ptr >= rc->buffer_end)
rc_read(rc);
rc->code = (rc->code << 8) | *rc->ptr++;
}
}
/* Called once. TODO: bb_maybe_free() */
static inline void INIT rc_free(struct rc *rc)
{
free(rc->buffer);
}
/* Called twice, but one callsite is in inline'd rc_is_bit_0_helper() */
static void INIT rc_do_normalize(struct rc *rc)
{
if (rc->ptr >= rc->buffer_end)
rc_read(rc);
rc->range <<= 8;
rc->code = (rc->code << 8) | *rc->ptr++;
}
static inline void INIT rc_normalize(struct rc *rc)
{
if (rc->range < (1 << RC_TOP_BITS))
rc_do_normalize(rc);
}
/* Called 9 times */
/* Why rc_is_bit_0_helper exists?
*Because we want to always expose (rc->code < rc->bound) to optimizer
*/
static inline uint32_t INIT rc_is_bit_0_helper(struct rc *rc, uint16_t *p)
{
rc_normalize(rc);
rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
return rc->bound;
}
static inline int INIT rc_is_bit_0(struct rc *rc, uint16_t *p)
{
uint32_t t = rc_is_bit_0_helper(rc, p);
return rc->code < t;
}
/* Called ~10 times, but very small, thus inlined */
static inline void INIT rc_update_bit_0(struct rc *rc, uint16_t *p)
{
rc->range = rc->bound;
*p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
}
static inline void rc_update_bit_1(struct rc *rc, uint16_t *p)
{
rc->range -= rc->bound;
rc->code -= rc->bound;
*p -= *p >> RC_MOVE_BITS;
}
/* Called 4 times in unlzma loop */
static int INIT rc_get_bit(struct rc *rc, uint16_t *p, int *symbol)
{
if (rc_is_bit_0(rc, p)) {
rc_update_bit_0(rc, p);
*symbol *= 2;
return 0;
} else {
rc_update_bit_1(rc, p);
*symbol = *symbol * 2 + 1;
return 1;
}
}
/* Called once */
static inline int INIT rc_direct_bit(struct rc *rc)
{
rc_normalize(rc);
rc->range >>= 1;
if (rc->code >= rc->range) {
rc->code -= rc->range;
return 1;
}
return 0;
}
/* Called twice */
static inline void INIT
rc_bit_tree_decode(struct rc *rc, uint16_t *p, int num_levels, int *symbol)
{
int i = num_levels;
*symbol = 1;
while (i--)
rc_get_bit(rc, p + *symbol, symbol);
*symbol -= 1 << num_levels;
}
/*
* Small lzma deflate implementation.
* Copyright (C) 2006 Aurelien Jacobs < aurel@gnuage.org >
*
* Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
* Copyright (C) 1999-2005 Igor Pavlov
*/
struct lzma_header {
uint8_t pos;
uint32_t dict_size;
uint64_t dst_size;
} __attribute__ ((packed)) ;
#define LZMA_BASE_SIZE 1846
#define LZMA_LIT_SIZE 768
#define LZMA_NUM_POS_BITS_MAX 4
#define LZMA_LEN_NUM_LOW_BITS 3
#define LZMA_LEN_NUM_MID_BITS 3
#define LZMA_LEN_NUM_HIGH_BITS 8
#define LZMA_LEN_CHOICE 0
#define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1)
#define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1)
#define LZMA_LEN_MID (LZMA_LEN_LOW \
+ (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS)))
#define LZMA_LEN_HIGH (LZMA_LEN_MID \
+(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS)))
#define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS))
#define LZMA_NUM_STATES 12
#define LZMA_NUM_LIT_STATES 7
#define LZMA_START_POS_MODEL_INDEX 4
#define LZMA_END_POS_MODEL_INDEX 14
#define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1))
#define LZMA_NUM_POS_SLOT_BITS 6
#define LZMA_NUM_LEN_TO_POS_STATES 4
#define LZMA_NUM_ALIGN_BITS 4
#define LZMA_MATCH_MIN_LEN 2
#define LZMA_IS_MATCH 0
#define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
#define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES)
#define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES)
#define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES)
#define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES)
#define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \
+ (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
#define LZMA_SPEC_POS (LZMA_POS_SLOT \
+(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS))
#define LZMA_ALIGN (LZMA_SPEC_POS \
+ LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX)
#define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS))
#define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS)
#define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
struct writer {
uint8_t *buffer;
uint8_t previous_byte;
size_t buffer_pos;
int bufsize;
size_t global_pos;
int(*flush)(void*, unsigned int);
struct lzma_header *header;
};
struct cstate {
int state;
uint32_t rep0, rep1, rep2, rep3;
};
static inline size_t INIT get_pos(struct writer *wr)
{
return
wr->global_pos + wr->buffer_pos;
}
static inline uint8_t INIT peek_old_byte(struct writer *wr,
uint32_t offs)
{
if (!wr->flush) {
int32_t pos;
while (offs > wr->header->dict_size)
offs -= wr->header->dict_size;
pos = wr->buffer_pos - offs;
return wr->buffer[pos];
} else {
uint32_t pos = wr->buffer_pos - offs;
while (pos >= wr->header->dict_size)
pos += wr->header->dict_size;
return wr->buffer[pos];
}
}
static inline void INIT write_byte(struct writer *wr, uint8_t byte)
{
wr->buffer[wr->buffer_pos++] = wr->previous_byte = byte;
if (wr->flush && wr->buffer_pos == wr->header->dict_size) {
wr->buffer_pos = 0;
wr->global_pos += wr->header->dict_size;
wr->flush((char *)wr->buffer, wr->header->dict_size);
}
}
static inline void INIT copy_byte(struct writer *wr, uint32_t offs)
{
write_byte(wr, peek_old_byte(wr, offs));
}
static inline void INIT copy_bytes(struct writer *wr,
uint32_t rep0, int len)
{
do {
copy_byte(wr, rep0);
len--;
} while (len != 0 && wr->buffer_pos < wr->header->dst_size);
}
static inline void INIT process_bit0(struct writer *wr, struct rc *rc,
struct cstate *cst, uint16_t *p,
int pos_state, uint16_t *prob,
int lc, uint32_t literal_pos_mask) {
int mi = 1;
rc_update_bit_0(rc, prob);
prob = (p + LZMA_LITERAL +
(LZMA_LIT_SIZE
* (((get_pos(wr) & literal_pos_mask) << lc)
+ (wr->previous_byte >> (8 - lc))))
);
if (cst->state >= LZMA_NUM_LIT_STATES) {
int match_byte = peek_old_byte(wr, cst->rep0);
do {
int bit;
uint16_t *prob_lit;
match_byte <<= 1;
bit = match_byte & 0x100;
prob_lit = prob + 0x100 + bit + mi;
if (rc_get_bit(rc, prob_lit, &mi)) {
if (!bit)
break;
} else {
if (bit)
break;
}
} while (mi < 0x100);
}
while (mi < 0x100) {
uint16_t *prob_lit = prob + mi;
rc_get_bit(rc, prob_lit, &mi);
}
write_byte(wr, mi);
if (cst->state < 4)
cst->state = 0;
else if (cst->state < 10)
cst->state -= 3;
else
cst->state -= 6;
}
static inline void INIT process_bit1(struct writer *wr, struct rc *rc,
struct cstate *cst, uint16_t *p,
int pos_state, uint16_t *prob) {
int offset;
uint16_t *prob_len;
int num_bits;
int len;
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP + cst->state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
cst->rep3 = cst->rep2;
cst->rep2 = cst->rep1;
cst->rep1 = cst->rep0;
cst->state = cst->state < LZMA_NUM_LIT_STATES ? 0 : 3;
prob = p + LZMA_LEN_CODER;
} else {
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G0 + cst->state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
prob = (p + LZMA_IS_REP_0_LONG
+ (cst->state <<
LZMA_NUM_POS_BITS_MAX) +
pos_state);
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
cst->state = cst->state < LZMA_NUM_LIT_STATES ?
9 : 11;
copy_byte(wr, cst->rep0);
return;
} else {
rc_update_bit_1(rc, prob);
}
} else {
uint32_t distance;
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G1 + cst->state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
distance = cst->rep1;
} else {
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G2 + cst->state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
distance = cst->rep2;
} else {
rc_update_bit_1(rc, prob);
distance = cst->rep3;
cst->rep3 = cst->rep2;
}
cst->rep2 = cst->rep1;
}
cst->rep1 = cst->rep0;
cst->rep0 = distance;
}
cst->state = cst->state < LZMA_NUM_LIT_STATES ? 8 : 11;
prob = p + LZMA_REP_LEN_CODER;
}
prob_len = prob + LZMA_LEN_CHOICE;
if (rc_is_bit_0(rc, prob_len)) {
rc_update_bit_0(rc, prob_len);
prob_len = (prob + LZMA_LEN_LOW
+ (pos_state <<
LZMA_LEN_NUM_LOW_BITS));
offset = 0;
num_bits = LZMA_LEN_NUM_LOW_BITS;
} else {
rc_update_bit_1(rc, prob_len);
prob_len = prob + LZMA_LEN_CHOICE_2;
if (rc_is_bit_0(rc, prob_len)) {
rc_update_bit_0(rc, prob_len);
prob_len = (prob + LZMA_LEN_MID
+ (pos_state <<
LZMA_LEN_NUM_MID_BITS));
offset = 1 << LZMA_LEN_NUM_LOW_BITS;
num_bits = LZMA_LEN_NUM_MID_BITS;
} else {
rc_update_bit_1(rc, prob_len);
prob_len = prob + LZMA_LEN_HIGH;
offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
+ (1 << LZMA_LEN_NUM_MID_BITS));
num_bits = LZMA_LEN_NUM_HIGH_BITS;
}
}
rc_bit_tree_decode(rc, prob_len, num_bits, &len);
len += offset;
if (cst->state < 4) {
int pos_slot;
cst->state += LZMA_NUM_LIT_STATES;
prob =
p + LZMA_POS_SLOT +
((len <
LZMA_NUM_LEN_TO_POS_STATES ? len :
LZMA_NUM_LEN_TO_POS_STATES - 1)
<< LZMA_NUM_POS_SLOT_BITS);
rc_bit_tree_decode(rc, prob,
LZMA_NUM_POS_SLOT_BITS,
&pos_slot);
if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
int i, mi;
num_bits = (pos_slot >> 1) - 1;
cst->rep0 = 2 | (pos_slot & 1);
if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
cst->rep0 <<= num_bits;
prob = p + LZMA_SPEC_POS +
cst->rep0 - pos_slot - 1;
} else {
num_bits -= LZMA_NUM_ALIGN_BITS;
while (num_bits--)
cst->rep0 = (cst->rep0 << 1) |
rc_direct_bit(rc);
prob = p + LZMA_ALIGN;
cst->rep0 <<= LZMA_NUM_ALIGN_BITS;
num_bits = LZMA_NUM_ALIGN_BITS;
}
i = 1;
mi = 1;
while (num_bits--) {
if (rc_get_bit(rc, prob + mi, &mi))
cst->rep0 |= i;
i <<= 1;
}
} else
cst->rep0 = pos_slot;
if (++(cst->rep0) == 0)
return;
}
len += LZMA_MATCH_MIN_LEN;
copy_bytes(wr, cst->rep0, len);
}
STATIC inline int INIT unlzma(unsigned char *buf, unsigned int in_len,
int(*fill)(void*, unsigned int),
int(*flush)(void*, unsigned int),
unsigned char *output,
unsigned int *posp,
void(*error_fn)(const char *x)
)
{
struct lzma_header header;
int lc, pb, lp;
uint32_t pos_state_mask;
uint32_t literal_pos_mask;
uint16_t *p;
int num_probs;
struct rc rc;
int i, mi;
struct writer wr;
struct cstate cst;
unsigned char *inbuf;
int ret = -1;
set_error_fn(error_fn);
if (buf)
inbuf = buf;
else
inbuf = malloc(LZMA_IOBUF_SIZE);
if (!inbuf) {
error("Could not allocate input bufer");
goto exit_0;
}
cst.state = 0;
cst.rep0 = cst.rep1 = cst.rep2 = cst.rep3 = 1;
wr.header = &header;
wr.flush = flush;
wr.global_pos = 0;
wr.previous_byte = 0;
wr.buffer_pos = 0;
rc_init(&rc, fill, inbuf, in_len);
for (i = 0; i < sizeof(header); i++) {
if (rc.ptr >= rc.buffer_end)
rc_read(&rc);
((unsigned char *)&header)[i] = *rc.ptr++;
}
if (header.pos >= (9 * 5 * 5))
error("bad header");
mi = 0;
lc = header.pos;
while (lc >= 9) {
mi++;
lc -= 9;
}
pb = 0;
lp = mi;
while (lp >= 5) {
pb++;
lp -= 5;
}
pos_state_mask = (1 << pb) - 1;
literal_pos_mask = (1 << lp) - 1;
ENDIAN_CONVERT(header.dict_size);
ENDIAN_CONVERT(header.dst_size);
if (header.dict_size == 0)
header.dict_size = 1;
if (output)
wr.buffer = output;
else {
wr.bufsize = MIN(header.dst_size, header.dict_size);
wr.buffer = large_malloc(wr.bufsize);
}
if (wr.buffer == NULL)
goto exit_1;
num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
p = (uint16_t *) large_malloc(num_probs * sizeof(*p));
if (p == 0)
goto exit_2;
num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
for (i = 0; i < num_probs; i++)
p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
rc_init_code(&rc);
while (get_pos(&wr) < header.dst_size) {
int pos_state = get_pos(&wr) & pos_state_mask;
uint16_t *prob = p + LZMA_IS_MATCH +
(cst.state << LZMA_NUM_POS_BITS_MAX) + pos_state;
if (rc_is_bit_0(&rc, prob))
process_bit0(&wr, &rc, &cst, p, pos_state, prob,
lc, literal_pos_mask);
else {
process_bit1(&wr, &rc, &cst, p, pos_state, prob);
if (cst.rep0 == 0)
break;
}
}
if (posp)
*posp = rc.ptr-rc.buffer;
if (wr.flush)
wr.flush(wr.buffer, wr.buffer_pos);
ret = 0;
large_free(p);
exit_2:
if (!output)
large_free(wr.buffer);
exit_1:
if (!buf)
free(inbuf);
exit_0:
return ret;
}
xen/include/xen/decompress.h
+38
View File
@@ -0,0 +1,38 @@
#ifndef __XEN_GENERIC_H
#define __XEN_GENERIC_H
typedef int decompress_fn(unsigned char *inbuf, unsigned int len,
int (*fill)(void*, unsigned int),
int (*flush)(void*, unsigned int),
unsigned char *outbuf, unsigned int *posp,
void (*error)(const char *x));
/* inbuf - input buffer
* len - len of pre-read data in inbuf
* fill - function to fill inbuf when empty
* flush - function to write out outbuf
* outbuf - output buffer
* posp - if non-null, input position (number of bytes read) will be
* returned here
* error - error reporting function
*
* If len != 0, inbuf should contain all the necessary input data, and fill
* should be NULL
* If len = 0, inbuf can be NULL, in which case the decompressor will allocate
* the input buffer. If inbuf != NULL it must be at least XXX_IOBUF_SIZE bytes.
* fill will be called (repeatedly...) to read data, at most XXX_IOBUF_SIZE
* bytes should be read per call. Replace XXX with the appropriate decompressor
* name, i.e. LZMA_IOBUF_SIZE.
*
* If flush = NULL, outbuf must be large enough to buffer all the expected
* output. If flush != NULL, the output buffer will be allocated by the
* decompressor (outbuf = NULL), and the flush function will be called to
* flush the output buffer at the appropriate time (decompressor and stream
* dependent).
*/
decompress_fn bunzip2, unlzma;
int decompress(void *inbuf, unsigned int len, void *outbuf);
#endif
Reference in new issue
xen-project/xen
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