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Add support for LZ4 decompression algorithm
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This patch adds support for LZ4-compressed FIT image contents. This
algorithm has a slightly worse compression ration than LZO while being
nearly twice as fast to decompress. When loading images from a fast
storage medium this usually results in a boot time win.

Sandbox-tested only since I don't have a U-Boot development system set
up right now. The code was imported unchanged from coreboot where it's
proven to work, though. I'm mostly interested in getting this recognized
by mkImage for use in a downstream project.

Signed-off-by: Julius Werner <[email protected]>
Acked-by: Simon Glass <[email protected]>
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jwerner-chromium authored and trini committed Oct 11, 2015
1 parent b6b5e39 commit 027b728
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9 changes: 9 additions & 0 deletions common/bootm.c
Original file line number Diff line number Diff line change
Expand Up @@ -389,6 +389,15 @@ int bootm_decomp_image(int comp, ulong load, ulong image_start, int type,
break;
}
#endif /* CONFIG_LZO */
#ifdef CONFIG_LZ4
case IH_COMP_LZ4: {
size_t size = unc_len;

ret = ulz4fn(image_buf, image_len, load_buf, &size);
image_len = size;
break;
}
#endif /* CONFIG_LZ4 */
default:
printf("Unimplemented compression type %d\n", comp);
return BOOTM_ERR_UNIMPLEMENTED;
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1 change: 1 addition & 0 deletions common/image.c
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Expand Up @@ -167,6 +167,7 @@ static const table_entry_t uimage_comp[] = {
{ IH_COMP_GZIP, "gzip", "gzip compressed", },
{ IH_COMP_LZMA, "lzma", "lzma compressed", },
{ IH_COMP_LZO, "lzo", "lzo compressed", },
{ IH_COMP_LZ4, "lz4", "lz4 compressed", },
{ -1, "", "", },
};

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1 change: 1 addition & 0 deletions configs/sandbox_defconfig
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Expand Up @@ -56,6 +56,7 @@ CONFIG_USB_STORAGE=y
CONFIG_SYS_VSNPRINTF=y
CONFIG_CMD_DHRYSTONE=y
CONFIG_TPM=y
CONFIG_LZ4=y
CONFIG_ERRNO_STR=y
CONFIG_UNIT_TEST=y
CONFIG_UT_TIME=y
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3 changes: 3 additions & 0 deletions include/common.h
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Expand Up @@ -826,6 +826,9 @@ int gzwrite(unsigned char *src, int len,
u64 startoffs,
u64 szexpected);

/* lib/lz4_wrapper.c */
int ulz4fn(const void *src, size_t srcn, void *dst, size_t *dstn);

/* lib/qsort.c */
void qsort(void *base, size_t nmemb, size_t size,
int(*compar)(const void *, const void *));
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1 change: 1 addition & 0 deletions include/image.h
Original file line number Diff line number Diff line change
Expand Up @@ -259,6 +259,7 @@ struct lmb;
#define IH_COMP_BZIP2 2 /* bzip2 Compression Used */
#define IH_COMP_LZMA 3 /* lzma Compression Used */
#define IH_COMP_LZO 4 /* lzo Compression Used */
#define IH_COMP_LZ4 5 /* lz4 Compression Used */

#define IH_MAGIC 0x27051956 /* Image Magic Number */
#define IH_NMLEN 32 /* Image Name Length */
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18 changes: 18 additions & 0 deletions lib/Kconfig
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Expand Up @@ -100,6 +100,24 @@ config SHA_PROG_HW_ACCEL
is performed in hardware.
endmenu

menu "Compression Support"

config LZ4
bool "Enable LZ4 decompression support"
help
If this option is set, support for LZ4 compressed images
is included. The LZ4 algorithm can run in-place as long as the
compressed image is loaded to the end of the output buffer, and
trades lower compression ratios for much faster decompression.

NOTE: This implements the release version of the LZ4 frame
format as generated by default by the 'lz4' command line tool.
This is not the same as the outdated, less efficient legacy
frame format currently (2015) implemented in the Linux kernel
(generated by 'lz4 -l'). The two formats are incompatible.

endmenu

config ERRNO_STR
bool "Enable function for getting errno-related string message"
help
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1 change: 1 addition & 0 deletions lib/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,7 @@ obj-$(CONFIG_GZIP_COMPRESSED) += gzip.o
obj-y += initcall.o
obj-$(CONFIG_LMB) += lmb.o
obj-y += ldiv.o
obj-$(CONFIG_LZ4) += lz4_wrapper.o
obj-$(CONFIG_MD5) += md5.o
obj-y += net_utils.o
obj-$(CONFIG_PHYSMEM) += physmem.o
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243 changes: 243 additions & 0 deletions lib/lz4.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,243 @@
/*
LZ4 - Fast LZ compression algorithm
Copyright (C) 2011-2015, Yann Collet.
SPDX-License-Identifier: BSD-2-Clause
You can contact the author at :
- LZ4 source repository : https://github.com/Cyan4973/lz4
- LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
*/


/**************************************
* Reading and writing into memory
**************************************/

/* customized version of memcpy, which may overwrite up to 7 bytes beyond dstEnd */
static void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd)
{
BYTE* d = (BYTE*)dstPtr;
const BYTE* s = (const BYTE*)srcPtr;
BYTE* e = (BYTE*)dstEnd;
do { LZ4_copy8(d,s); d+=8; s+=8; } while (d<e);
}


/**************************************
* Common Constants
**************************************/
#define MINMATCH 4

#define COPYLENGTH 8
#define LASTLITERALS 5
#define MFLIMIT (COPYLENGTH+MINMATCH)
static const int LZ4_minLength = (MFLIMIT+1);

#define KB *(1 <<10)
#define MB *(1 <<20)
#define GB *(1U<<30)

#define MAXD_LOG 16
#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)

#define ML_BITS 4
#define ML_MASK ((1U<<ML_BITS)-1)
#define RUN_BITS (8-ML_BITS)
#define RUN_MASK ((1U<<RUN_BITS)-1)


/**************************************
* Local Structures and types
**************************************/
typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
typedef enum { full = 0, partial = 1 } earlyEnd_directive;



/*******************************
* Decompression functions
*******************************/
/*
* This generic decompression function cover all use cases.
* It shall be instantiated several times, using different sets of directives
* Note that it is essential this generic function is really inlined,
* in order to remove useless branches during compilation optimization.
*/
FORCE_INLINE int LZ4_decompress_generic(
const char* const source,
char* const dest,
int inputSize,
int outputSize, /* If endOnInput==endOnInputSize, this value is the max size of Output Buffer. */

int endOnInput, /* endOnOutputSize, endOnInputSize */
int partialDecoding, /* full, partial */
int targetOutputSize, /* only used if partialDecoding==partial */
int dict, /* noDict, withPrefix64k, usingExtDict */
const BYTE* const lowPrefix, /* == dest if dict == noDict */
const BYTE* const dictStart, /* only if dict==usingExtDict */
const size_t dictSize /* note : = 0 if noDict */
)
{
/* Local Variables */
const BYTE* ip = (const BYTE*) source;
const BYTE* const iend = ip + inputSize;

BYTE* op = (BYTE*) dest;
BYTE* const oend = op + outputSize;
BYTE* cpy;
BYTE* oexit = op + targetOutputSize;
const BYTE* const lowLimit = lowPrefix - dictSize;

const BYTE* const dictEnd = (const BYTE*)dictStart + dictSize;
const size_t dec32table[] = {4, 1, 2, 1, 4, 4, 4, 4};
const size_t dec64table[] = {0, 0, 0, (size_t)-1, 0, 1, 2, 3};

const int safeDecode = (endOnInput==endOnInputSize);
const int checkOffset = ((safeDecode) && (dictSize < (int)(64 KB)));


/* Special cases */
if ((partialDecoding) && (oexit> oend-MFLIMIT)) oexit = oend-MFLIMIT; /* targetOutputSize too high => decode everything */
if ((endOnInput) && (unlikely(outputSize==0))) return ((inputSize==1) && (*ip==0)) ? 0 : -1; /* Empty output buffer */
if ((!endOnInput) && (unlikely(outputSize==0))) return (*ip==0?1:-1);


/* Main Loop */
while (1)
{
unsigned token;
size_t length;
const BYTE* match;

/* get literal length */
token = *ip++;
if ((length=(token>>ML_BITS)) == RUN_MASK)
{
unsigned s;
do
{
s = *ip++;
length += s;
}
while (likely((endOnInput)?ip<iend-RUN_MASK:1) && (s==255));
if ((safeDecode) && unlikely((size_t)(op+length)<(size_t)(op))) goto _output_error; /* overflow detection */
if ((safeDecode) && unlikely((size_t)(ip+length)<(size_t)(ip))) goto _output_error; /* overflow detection */
}

/* copy literals */
cpy = op+length;
if (((endOnInput) && ((cpy>(partialDecoding?oexit:oend-MFLIMIT)) || (ip+length>iend-(2+1+LASTLITERALS))) )
|| ((!endOnInput) && (cpy>oend-COPYLENGTH)))
{
if (partialDecoding)
{
if (cpy > oend) goto _output_error; /* Error : write attempt beyond end of output buffer */
if ((endOnInput) && (ip+length > iend)) goto _output_error; /* Error : read attempt beyond end of input buffer */
}
else
{
if ((!endOnInput) && (cpy != oend)) goto _output_error; /* Error : block decoding must stop exactly there */
if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) goto _output_error; /* Error : input must be consumed */
}
memcpy(op, ip, length);
ip += length;
op += length;
break; /* Necessarily EOF, due to parsing restrictions */
}
LZ4_wildCopy(op, ip, cpy);
ip += length; op = cpy;

/* get offset */
match = cpy - LZ4_readLE16(ip); ip+=2;
if ((checkOffset) && (unlikely(match < lowLimit))) goto _output_error; /* Error : offset outside destination buffer */

/* get matchlength */
length = token & ML_MASK;
if (length == ML_MASK)
{
unsigned s;
do
{
if ((endOnInput) && (ip > iend-LASTLITERALS)) goto _output_error;
s = *ip++;
length += s;
} while (s==255);
if ((safeDecode) && unlikely((size_t)(op+length)<(size_t)op)) goto _output_error; /* overflow detection */
}
length += MINMATCH;

/* check external dictionary */
if ((dict==usingExtDict) && (match < lowPrefix))
{
if (unlikely(op+length > oend-LASTLITERALS)) goto _output_error; /* doesn't respect parsing restriction */

if (length <= (size_t)(lowPrefix-match))
{
/* match can be copied as a single segment from external dictionary */
match = dictEnd - (lowPrefix-match);
memmove(op, match, length); op += length;
}
else
{
/* match encompass external dictionary and current segment */
size_t copySize = (size_t)(lowPrefix-match);
memcpy(op, dictEnd - copySize, copySize);
op += copySize;
copySize = length - copySize;
if (copySize > (size_t)(op-lowPrefix)) /* overlap within current segment */
{
BYTE* const endOfMatch = op + copySize;
const BYTE* copyFrom = lowPrefix;
while (op < endOfMatch) *op++ = *copyFrom++;
}
else
{
memcpy(op, lowPrefix, copySize);
op += copySize;
}
}
continue;
}

/* copy repeated sequence */
cpy = op + length;
if (unlikely((op-match)<8))
{
const size_t dec64 = dec64table[op-match];
op[0] = match[0];
op[1] = match[1];
op[2] = match[2];
op[3] = match[3];
match += dec32table[op-match];
LZ4_copy4(op+4, match);
op += 8; match -= dec64;
} else { LZ4_copy8(op, match); op+=8; match+=8; }

if (unlikely(cpy>oend-12))
{
if (cpy > oend-LASTLITERALS) goto _output_error; /* Error : last LASTLITERALS bytes must be literals */
if (op < oend-8)
{
LZ4_wildCopy(op, match, oend-8);
match += (oend-8) - op;
op = oend-8;
}
while (op<cpy) *op++ = *match++;
}
else
LZ4_wildCopy(op, match, cpy);
op=cpy; /* correction */
}

/* end of decoding */
if (endOnInput)
return (int) (((char*)op)-dest); /* Nb of output bytes decoded */
else
return (int) (((const char*)ip)-source); /* Nb of input bytes read */

/* Overflow error detected */
_output_error:
return (int) (-(((const char*)ip)-source))-1;
}
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