summaryrefslogtreecommitdiffstats
path: root/target/image/brcm/lzma-loader/src/decompress.c
blob: ec510e21e387d057d5cae667a5aa7400ae5be875 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
/*
 * 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)();
	}
}