openwrt/target/linux/brcm-2.6/image/lzma-loader/src/decompress.c

176 lines
4.8 KiB
C

/*
* LZMA compressed kernel decompressor for bcm947xx boards
*
* Copyright (C) 2005 by Oleg I. Vdovikin <oleg@cs.msu.su>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*
* Please note, this was code based on the bunzip2 decompressor code
* by Manuel Novoa III (mjn3@codepoet.org), although the only thing left
* is an idea and part of original vendor code
*
*
* 12-Mar-2005 Mineharu Takahara <mtakahar@yahoo.com>
* pass actual output size to decoder (stream mode
* compressed input is not a requirement anymore)
*
* 24-Apr-2005 Oleg I. Vdovikin
* reordered functions using lds script, removed forward decl
*
*/
#include "LzmaDecode.h"
#define BCM4710_FLASH 0x1fc00000 /* Flash */
#define KSEG0 0x80000000
#define KSEG1 0xa0000000
#define KSEG1ADDR(a) ((((unsigned)(a)) & 0x1fffffffU) | KSEG1)
#define Index_Invalidate_I 0x00
#define Index_Writeback_Inv_D 0x01
#define cache_unroll(base,op) \
__asm__ __volatile__( \
".set noreorder;\n" \
".set mips3;\n" \
"cache %1, (%0);\n" \
".set mips0;\n" \
".set reorder\n" \
: \
: "r" (base), \
"i" (op));
static __inline__ void blast_icache(unsigned long size, unsigned long lsize)
{
unsigned long start = KSEG0;
unsigned long end = (start + size);
while(start < end) {
cache_unroll(start,Index_Invalidate_I);
start += lsize;
}
}
static __inline__ void blast_dcache(unsigned long size, unsigned long lsize)
{
unsigned long start = KSEG0;
unsigned long end = (start + size);
while(start < end) {
cache_unroll(start,Index_Writeback_Inv_D);
start += lsize;
}
}
#define TRX_MAGIC 0x30524448 /* "HDR0" */
struct trx_header {
unsigned int magic; /* "HDR0" */
unsigned int len; /* Length of file including header */
unsigned int crc32; /* 32-bit CRC from flag_version to end of file */
unsigned int flag_version; /* 0:15 flags, 16:31 version */
unsigned int offsets[3]; /* Offsets of partitions from start of header */
};
/* beyound the image end, size not known in advance */
extern unsigned char workspace[];
unsigned int offset;
unsigned char *data;
/* flash access should be aligned, so wrapper is used */
/* read byte from the flash, all accesses are 32-bit aligned */
static int read_byte(void *object, unsigned char **buffer, UInt32 *bufferSize)
{
static unsigned int val;
if (((unsigned int)offset % 4) == 0) {
val = *(unsigned int *)data;
data += 4;
}
*bufferSize = 1;
*buffer = ((unsigned char *)&val) + (offset++ & 3);
return LZMA_RESULT_OK;
}
static __inline__ unsigned char get_byte(void)
{
unsigned char *buffer;
UInt32 fake;
return read_byte(0, &buffer, &fake), *buffer;
}
/* should be the first function */
void entry(unsigned long icache_size, unsigned long icache_lsize,
unsigned long dcache_size, unsigned long dcache_lsize)
{
unsigned int i; /* temp value */
unsigned int lc; /* literal context bits */
unsigned int lp; /* literal pos state bits */
unsigned int pb; /* pos state bits */
unsigned int osize; /* uncompressed size */
ILzmaInCallback callback;
callback.Read = read_byte;
/* look for trx header, 32-bit data access */
for (data = ((unsigned char *) KSEG1ADDR(BCM4710_FLASH));
((struct trx_header *)data)->magic != TRX_MAGIC; data += 65536);
/* compressed kernel is in the partition 0 or 1 */
if (((struct trx_header *)data)->offsets[1] > 65536)
data += ((struct trx_header *)data)->offsets[0];
else
data += ((struct trx_header *)data)->offsets[1];
offset = 0;
/* lzma args */
i = get_byte();
lc = i % 9, i = i / 9;
lp = i % 5, pb = i / 5;
/* skip rest of the LZMA coder property */
for (i = 0; i < 4; i++)
get_byte();
/* read the lower half of uncompressed size in the header */
osize = ((unsigned int)get_byte()) +
((unsigned int)get_byte() << 8) +
((unsigned int)get_byte() << 16) +
((unsigned int)get_byte() << 24);
/* skip rest of the header (upper half of uncompressed size) */
for (i = 0; i < 4; i++)
get_byte();
/* decompress kernel */
if (LzmaDecode(workspace, ~0, lc, lp, pb, &callback,
(unsigned char*)LOADADDR, osize, &i) == LZMA_RESULT_OK)
{
blast_dcache(dcache_size, dcache_lsize);
blast_icache(icache_size, icache_lsize);
/* Jump to load address */
((void (*)(void)) LOADADDR)();
}
}