1/*
2 * LZMA compressed kernel decompressor for bcm947xx boards
3 *
4 * Copyright (C) 2005 by Oleg I. Vdovikin <oleg@cs.msu.su>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 *
21 * Please note, this was code based on the bunzip2 decompressor code
22 * by Manuel Novoa III  (mjn3@codepoet.org), although the only thing left
23 * is an idea and part of original vendor code
24 *
25 *
26 * 12-Mar-2005  Mineharu Takahara <mtakahar@yahoo.com>
27 *   pass actual output size to decoder (stream mode
28 *   compressed input is not a requirement anymore)
29 *
30 * 24-Apr-2005 Oleg I. Vdovikin
31 *   reordered functions using lds script, removed forward decl
32 *
33 */
34
35#include "LzmaDecode.h"
36
37#define BCM4710_FLASH		0x1fc00000	/* Flash */
38
39#define KSEG0			0x80000000
40#define KSEG1			0xa0000000
41
42#define KSEG1ADDR(a)		((((unsigned)(a)) & 0x1fffffffU) | KSEG1)
43
44#define Index_Invalidate_I	0x00
45#define Index_Writeback_Inv_D   0x01
46
47#define cache_unroll(base,op)	\
48	__asm__ __volatile__(		\
49		".set noreorder;\n"		\
50		".set mips3;\n"			\
51		"cache %1, (%0);\n"		\
52		".set mips0;\n"			\
53		".set reorder\n"		\
54		:						\
55		: "r" (base),			\
56		  "i" (op));
57
58static __inline__ void blast_icache(unsigned long size, unsigned long lsize)
59{
60	unsigned long start = KSEG0;
61	unsigned long end = (start + size);
62
63	while(start < end) {
64		cache_unroll(start,Index_Invalidate_I);
65		start += lsize;
66	}
67}
68
69static __inline__ void blast_dcache(unsigned long size, unsigned long lsize)
70{
71	unsigned long start = KSEG0;
72	unsigned long end = (start + size);
73
74	while(start < end) {
75		cache_unroll(start,Index_Writeback_Inv_D);
76		start += lsize;
77	}
78}
79
80#define TRX_MAGIC       0x30524448      /* "HDR0" */
81
82struct trx_header {
83	unsigned int magic;		/* "HDR0" */
84	unsigned int len;		/* Length of file including header */
85	unsigned int crc32;		/* 32-bit CRC from flag_version to end of file */
86	unsigned int flag_version;	/* 0:15 flags, 16:31 version */
87	unsigned int offsets[3];	/* Offsets of partitions from start of header */
88};
89
90#define EDIMAX_PS_HEADER_MAGIC	0x36315350 /*  "PS16"  */
91#define EDIMAX_PS_HEADER_LEN	0xc /* 12 bytes long for edimax header */
92
93/* beyound the image end, size not known in advance */
94extern unsigned char workspace[];
95
96unsigned int offset;
97unsigned char *data;
98
99/* flash access should be aligned, so wrapper is used */
100/* read byte from the flash, all accesses are 32-bit aligned */
101static int read_byte(void *object, unsigned char **buffer, UInt32 *bufferSize)
102{
103	static unsigned int val;
104
105	if (((unsigned int)offset % 4) == 0) {
106		val = *(unsigned int *)data;
107		data += 4;
108	}
109
110	*bufferSize = 1;
111	*buffer = ((unsigned char *)&val) + (offset++ & 3);
112
113	return LZMA_RESULT_OK;
114}
115
116static __inline__ unsigned char get_byte(void)
117{
118	unsigned char *buffer;
119	UInt32 fake;
120
121	return read_byte(0, &buffer, &fake), *buffer;
122}
123
124/* should be the first function */
125void entry(unsigned long icache_size, unsigned long icache_lsize,
126	unsigned long dcache_size, unsigned long dcache_lsize,
127	unsigned long fw_arg0, unsigned long fw_arg1,
128	unsigned long fw_arg2, unsigned long fw_arg3)
129{
130	unsigned int i;  /* temp value */
131	unsigned int lc; /* literal context bits */
132	unsigned int lp; /* literal pos state bits */
133	unsigned int pb; /* pos state bits */
134	unsigned int osize; /* uncompressed size */
135
136	ILzmaInCallback callback;
137	callback.Read = read_byte;
138
139	/* look for trx header, 32-bit data access */
140	for (data = ((unsigned char *) KSEG1ADDR(BCM4710_FLASH));
141		((struct trx_header *)data)->magic != TRX_MAGIC &&
142		((struct trx_header *)data)->magic != EDIMAX_PS_HEADER_MAGIC;
143		 data += 65536);
144
145	if (((struct trx_header *)data)->magic == EDIMAX_PS_HEADER_MAGIC)
146		data += EDIMAX_PS_HEADER_LEN;
147	/* compressed kernel is in the partition 0 or 1 */
148	if (((struct trx_header *)data)->offsets[1] > 65536)
149		data += ((struct trx_header *)data)->offsets[0];
150	else
151		data += ((struct trx_header *)data)->offsets[1];
152
153	offset = 0;
154
155	/* lzma args */
156	i = get_byte();
157	lc = i % 9, i = i / 9;
158	lp = i % 5, pb = i / 5;
159
160	/* skip rest of the LZMA coder property */
161	for (i = 0; i < 4; i++)
162		get_byte();
163
164	/* read the lower half of uncompressed size in the header */
165	osize = ((unsigned int)get_byte()) +
166		((unsigned int)get_byte() << 8) +
167		((unsigned int)get_byte() << 16) +
168		((unsigned int)get_byte() << 24);
169
170	/* skip rest of the header (upper half of uncompressed size) */
171	for (i = 0; i < 4; i++)
172		get_byte();
173
174	/* decompress kernel */
175	if (LzmaDecode(workspace, ~0, lc, lp, pb, &callback,
176		(unsigned char*)LOADADDR, osize, &i) == LZMA_RESULT_OK)
177	{
178		blast_dcache(dcache_size, dcache_lsize);
179		blast_icache(icache_size, icache_lsize);
180
181		/* Jump to load address */
182		((void (*)(unsigned long, unsigned long, unsigned long,
183			unsigned long)) LOADADDR)(fw_arg0, fw_arg1, fw_arg2,
184				fw_arg3);
185	}
186}
187