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

   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  * ??-Nov-2005 Mike Baker
  34  *   reorder the script as an lzma wrapper; do not depend on flash access
  35  */
  36
  37 #include "LzmaDecode.h"
  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
  58
  59 static __inline__ void blast_icache(unsigned long size, unsigned long lsize)
  60 {
  61         unsigned long start = KSEG0;
  62         unsigned long end = (start + size);
  63
  64         while(start < end) {
  65                 cache_unroll(start,Index_Invalidate_I);
  66                 start += lsize;
  67         }
  68 }
  69
  70 static __inline__ void blast_dcache(unsigned long size, unsigned long lsize)
  71 {
  72         unsigned long start = KSEG0;
  73         unsigned long end = (start + size);
  74
  75         while(start < end) {
  76                 cache_unroll(start,Index_Writeback_Inv_D);
  77                 start += lsize;
  78         }
  79 }
  80
  81 unsigned char *data;
  82
  83 static int read_byte(void *object, unsigned char **buffer, UInt32 *bufferSize)
  84 {
  85         *bufferSize = 1;
  86         *buffer = data;
  87         ++data;
  88         return LZMA_RESULT_OK;
  89 }
  90
  91 static __inline__ unsigned char get_byte(void)
  92 {
  93         unsigned char *buffer;
  94         UInt32 fake;
  95
  96         return read_byte(0, &buffer, &fake), *buffer;
  97 }
  98
  99 /* This puts lzma workspace 128k below RAM end.
 100  * That should be enough for both lzma and stack
 101  */
 102 static char *buffer = (char *)(RAMSTART + RAMSIZE - 0x00020000);
 103 extern char lzma_start[];
 104 extern char lzma_end[];
 105
 106 /* should be the first function */
 107 void entry(unsigned long icache_size, unsigned long icache_lsize,
 108         unsigned long dcache_size, unsigned long dcache_lsize)
 109 {
 110         unsigned int i;  /* temp value */
 111         unsigned int osize; /* uncompressed size */
 112         volatile unsigned int arg0, arg1, arg2, arg3;
 113
 114         /* restore argument registers */
 115         __asm__ __volatile__ ("ori %0, $12, 0":"=r"(arg0));
 116         __asm__ __volatile__ ("ori %0, $13, 0":"=r"(arg1));
 117         __asm__ __volatile__ ("ori %0, $14, 0":"=r"(arg2));
 118         __asm__ __volatile__ ("ori %0, $15, 0":"=r"(arg3));
 119
 120         ILzmaInCallback callback;
 121         CLzmaDecoderState vs;
 122         callback.Read = read_byte;
 123
 124         data = lzma_start;
 125
 126         /* lzma args */
 127         i = get_byte();
 128         vs.Properties.lc = i % 9, i = i / 9;
 129         vs.Properties.lp = i % 5, vs.Properties.pb = i / 5;
 130
 131         vs.Probs = (CProb *)buffer;
 132
 133         /* skip rest of the LZMA coder property */
 134         for (i = 0; i < 4; i++)
 135                 get_byte();
 136
 137         /* read the lower half of uncompressed size in the header */
 138         osize = ((unsigned int)get_byte()) +
 139                 ((unsigned int)get_byte() << 8) +
 140                 ((unsigned int)get_byte() << 16) +
 141                 ((unsigned int)get_byte() << 24);
 142
 143         /* skip rest of the header (upper half of uncompressed size) */
 144         for (i = 0; i < 4; i++)
 145                 get_byte();
 146
 147         /* decompress kernel */
 148         if ((i = LzmaDecode(&vs, &callback,
 149         (unsigned char*)KERNEL_ENTRY, osize, &osize)) == LZMA_RESULT_OK)
 150         {
 151                 blast_dcache(dcache_size, dcache_lsize);
 152                 blast_icache(icache_size, icache_lsize);
 153
 154                 /* Jump to load address */
 155                 ((void (*)(int a0, int a1, int a2, int a3)) KERNEL_ENTRY)(arg0, arg1, arg2, arg3);
 156         }
 157 }