1 // SPDX-License-Identifier: 0BSD
2
3 ///////////////////////////////////////////////////////////////////////////////
4 //
5 /// \file powerpc.c
6 /// \brief Filter for PowerPC (big endian) binaries
7 ///
8 // Authors: Igor Pavlov
9 // Lasse Collin
10 //
11 ///////////////////////////////////////////////////////////////////////////////
12
13 #include "simple_private.h"
14
15
16 static size_t
powerpc_code(void * simple lzma_attribute ((__unused__)),uint32_t now_pos,bool is_encoder,uint8_t * buffer,size_t size)17 powerpc_code(void *simple lzma_attribute((__unused__)),
18 uint32_t now_pos, bool is_encoder,
19 uint8_t *buffer, size_t size)
20 {
21 size &= ~(size_t)3;
22
23 size_t i;
24 for (i = 0; i < size; i += 4) {
25 // PowerPC branch 6(48) 24(Offset) 1(Abs) 1(Link)
26 if ((buffer[i] >> 2) == 0x12
27 && ((buffer[i + 3] & 3) == 1)) {
28
29 const uint32_t src
30 = (((uint32_t)(buffer[i + 0]) & 3) << 24)
31 | ((uint32_t)(buffer[i + 1]) << 16)
32 | ((uint32_t)(buffer[i + 2]) << 8)
33 | ((uint32_t)(buffer[i + 3]) & ~UINT32_C(3));
34
35 uint32_t dest;
36 if (is_encoder)
37 dest = now_pos + (uint32_t)(i) + src;
38 else
39 dest = src - (now_pos + (uint32_t)(i));
40
41 buffer[i + 0] = 0x48 | ((dest >> 24) & 0x03);
42 buffer[i + 1] = (dest >> 16);
43 buffer[i + 2] = (dest >> 8);
44 buffer[i + 3] &= 0x03;
45 buffer[i + 3] |= dest;
46 }
47 }
48
49 return i;
50 }
51
52
53 static lzma_ret
powerpc_coder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters,bool is_encoder)54 powerpc_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
55 const lzma_filter_info *filters, bool is_encoder)
56 {
57 return lzma_simple_coder_init(next, allocator, filters,
58 &powerpc_code, 0, 4, 4, is_encoder);
59 }
60
61
62 #ifdef HAVE_ENCODER_POWERPC
63 extern lzma_ret
lzma_simple_powerpc_encoder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters)64 lzma_simple_powerpc_encoder_init(lzma_next_coder *next,
65 const lzma_allocator *allocator,
66 const lzma_filter_info *filters)
67 {
68 return powerpc_coder_init(next, allocator, filters, true);
69 }
70 #endif
71
72
73 #ifdef HAVE_DECODER_POWERPC
74 extern lzma_ret
lzma_simple_powerpc_decoder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters)75 lzma_simple_powerpc_decoder_init(lzma_next_coder *next,
76 const lzma_allocator *allocator,
77 const lzma_filter_info *filters)
78 {
79 return powerpc_coder_init(next, allocator, filters, false);
80 }
81 #endif
82