1 ///////////////////////////////////////////////////////////////////////////////
2 //
3 /// \file powerpc.c
4 /// \brief Filter for PowerPC (big endian) 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
powerpc_code(void * simple lzma_attribute ((__unused__)),uint32_t now_pos,bool is_encoder,uint8_t * buffer,size_t size)18 powerpc_code(void *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 // PowerPC branch 6(48) 24(Offset) 1(Abs) 1(Link)
25 if ((buffer[i] >> 2) == 0x12
26 && ((buffer[i + 3] & 3) == 1)) {
27
28 const uint32_t src
29 = (((uint32_t)(buffer[i + 0]) & 3) << 24)
30 | ((uint32_t)(buffer[i + 1]) << 16)
31 | ((uint32_t)(buffer[i + 2]) << 8)
32 | ((uint32_t)(buffer[i + 3]) & ~UINT32_C(3));
33
34 uint32_t dest;
35 if (is_encoder)
36 dest = now_pos + (uint32_t)(i) + src;
37 else
38 dest = src - (now_pos + (uint32_t)(i));
39
40 buffer[i + 0] = 0x48 | ((dest >> 24) & 0x03);
41 buffer[i + 1] = (dest >> 16);
42 buffer[i + 2] = (dest >> 8);
43 buffer[i + 3] &= 0x03;
44 buffer[i + 3] |= dest;
45 }
46 }
47
48 return i;
49 }
50
51
52 static lzma_ret
powerpc_coder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters,bool is_encoder)53 powerpc_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
54 const lzma_filter_info *filters, bool is_encoder)
55 {
56 return lzma_simple_coder_init(next, allocator, filters,
57 &powerpc_code, 0, 4, 4, is_encoder);
58 }
59
60
61 extern lzma_ret
lzma_simple_powerpc_encoder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters)62 lzma_simple_powerpc_encoder_init(lzma_next_coder *next,
63 const lzma_allocator *allocator,
64 const lzma_filter_info *filters)
65 {
66 return powerpc_coder_init(next, allocator, filters, true);
67 }
68
69
70 extern lzma_ret
lzma_simple_powerpc_decoder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters)71 lzma_simple_powerpc_decoder_init(lzma_next_coder *next,
72 const lzma_allocator *allocator,
73 const lzma_filter_info *filters)
74 {
75 return powerpc_coder_init(next, allocator, filters, false);
76 }
77