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 --- 2009-10-27.orig/xen/arch/x86/bzimage.c 2009-10-07 13:31:36.000000000 +0200 +++ 2009-10-27/xen/arch/x86/bzimage.c 2009-11-05 12:23:05.000000000 +0100 @@ -4,6 +4,7 @@ #include #include #include +#include #include #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 * } else { - *_image_start = (char *)window; - *image_len = gzip_length(image, *image_len); rc = 0; } @@ -203,9 +212,12 @@ int __init bzimage_headroom(char *image_ 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_bas { 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_bas *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); + + if ( !err ) + { + *image_start = image_base; + *image_len = output_len; + } - return 0; + return err > 0 ? 0 : err; } /* --- 2009-10-27.orig/xen/common/Makefile 2009-05-27 13:54:07.000000000 +0200 +++ 2009-10-27/xen/common/Makefile 2009-11-05 12:26:53.000000000 +0100 @@ -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 --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ 2009-10-27/xen/common/bunzip2.c 2009-11-05 12:44:51.000000000 +0100 @@ -0,0 +1,726 @@ +/* vi: set sw = 4 ts = 4: */ +/* Small bzip2 deflate implementation, by Rob Landley (rob@xxxxxxxxxxx). + + Based on bzip2 decompression code by Julian R Seward (jseward@xxxxxxx), + 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@xxxxxxxxxxxx). + + 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@xxxxxxxx) +*/ + +#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; +} --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ 2009-10-27/xen/common/decompress.c 2009-11-05 12:27:10.000000000 +0100 @@ -0,0 +1,27 @@ +#include +#include +#include +#include +#include + +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; +} --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ 2009-10-27/xen/common/decompress.h 2009-11-05 15:21:52.000000000 +0100 @@ -0,0 +1,19 @@ +#include +#include +#include +#include +#include +#include +#include + +#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 --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ 2009-10-27/xen/common/unlzma.c 2009-11-05 12:45:37.000000000 +0100 @@ -0,0 +1,647 @@ +/* Lzma decompressor for Linux kernel. Shamelessly snarfed + * from busybox 1.1.1 + * + * Linux kernel adaptation + * Copyright (C) 2006 Alain < alain@xxxxxxxx > + * + * Based on small lzma deflate implementation/Small range coder + * implementation for lzma. + * Copyright (C) 2006 Aurelien Jacobs < aurel@xxxxxxxxxx > + * + * 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@xxxxxxxxxx > + * + * Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/) + * Copyright (c) 1999-2005 Igor Pavlov + */ + +#include + +#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@xxxxxxxxxx > + * + * 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; +} --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ 2009-10-27/xen/include/xen/decompress.h 2009-11-05 12:27:44.000000000 +0100 @@ -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