src/liblzma/simple/sparc.c

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 /// \file       sparc.c
   4 /// \brief      Filter for SPARC binaries
   5 ///
   6 //  Authors:    Igor Pavlov
   7 //              Lasse Collin
   8 //
   9 //  This file has been put into the public domain.
  10 //  You can do whatever you want with this file.
  11 //
  12 ///////////////////////////////////////////////////////////////////////////////
  13
  14 #include "simple_private.h"
  15
  16
  17 static size_t
  18 sparc_code(lzma_simple *simple lzma_attribute((unused)),
  19                 uint32_t now_pos, bool is_encoder,
  20                 uint8_t *buffer, size_t size)
  21 {
  22         size_t i;
  23         for (i = 0; i + 4 <= size; i += 4) {
  24
  25                 if ((buffer[i] == 0x40 && (buffer[i + 1] & 0xC0) == 0x00)
  26                                 || (buffer[i] == 0x7F
  27                                 && (buffer[i + 1] & 0xC0) == 0xC0)) {
  28
  29                         uint32_t src = ((uint32_t)buffer[i + 0] << 24)
  30                                         | ((uint32_t)buffer[i + 1] << 16)
  31                                         | ((uint32_t)buffer[i + 2] << 8)
  32                                         | ((uint32_t)buffer[i + 3]);
  33
  34                         src <<= 2;
  35
  36                         uint32_t dest;
  37                         if (is_encoder)
  38                                 dest = now_pos + (uint32_t)(i) + src;
  39                         else
  40                                 dest = src - (now_pos + (uint32_t)(i));
  41
  42                         dest >>= 2;
  43
  44                         dest = (((0 - ((dest >> 22) & 1)) << 22) & 0x3FFFFFFF)
  45                                         | (dest & 0x3FFFFF)
  46                                         | 0x40000000;
  47
  48                         buffer[i + 0] = (uint8_t)(dest >> 24);
  49                         buffer[i + 1] = (uint8_t)(dest >> 16);
  50                         buffer[i + 2] = (uint8_t)(dest >> 8);
  51                         buffer[i + 3] = (uint8_t)(dest);
  52                 }
  53         }
  54
  55         return i;
  56 }
  57
  58
  59 static lzma_ret
  60 sparc_coder_init(lzma_next_coder *next, lzma_allocator *allocator,
  61                 const lzma_filter_info *filters, bool is_encoder)
  62 {
  63         return lzma_simple_coder_init(next, allocator, filters,
  64                         &sparc_code, 0, 4, is_encoder);
  65 }
  66
  67
  68 extern lzma_ret
  69 lzma_simple_sparc_encoder_init(lzma_next_coder *next,
  70                 lzma_allocator *allocator, const lzma_filter_info *filters)
  71 {
  72         return sparc_coder_init(next, allocator, filters, true);
  73 }
  74
  75
  76 extern lzma_ret
  77 lzma_simple_sparc_decoder_init(lzma_next_coder *next,
  78                 lzma_allocator *allocator, const lzma_filter_info *filters)
  79 {
  80         return sparc_coder_init(next, allocator, filters, false);
  81 }