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_t i;
22 for (i = 0; i + 4 <= size; i += 4) {
23 // PowerPC branch 6(48) 24(Offset) 1(Abs) 1(Link)
24 if ((buffer[i] >> 2) == 0x12
25 && ((buffer[i + 3] & 3) == 1)) {
26
27 const uint32_t src
28 = (((uint32_t)(buffer[i + 0]) & 3) << 24)
29 | ((uint32_t)(buffer[i + 1]) << 16)
30 | ((uint32_t)(buffer[i + 2]) << 8)
31 | ((uint32_t)(buffer[i + 3]) & ~UINT32_C(3));
32
33 uint32_t dest;
34 if (is_encoder)
35 dest = now_pos + (uint32_t)(i) + src;
36 else
37 dest = src - (now_pos + (uint32_t)(i));
38
39 buffer[i + 0] = 0x48 | ((dest >> 24) & 0x03);
40 buffer[i + 1] = (dest >> 16);
41 buffer[i + 2] = (dest >> 8);
42 buffer[i + 3] &= 0x03;
43 buffer[i + 3] |= dest;
44 }
45 }
46
47 return i;
48 }
49
50
51 static lzma_ret
powerpc_coder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters,bool is_encoder)52 powerpc_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
53 const lzma_filter_info *filters, bool is_encoder)
54 {
55 return lzma_simple_coder_init(next, allocator, filters,
56 &powerpc_code, 0, 4, 4, is_encoder);
57 }
58
59
60 #ifdef HAVE_ENCODER_POWERPC
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 #endif
69
70
71 #ifdef HAVE_DECODER_POWERPC
72 extern lzma_ret
lzma_simple_powerpc_decoder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters)73 lzma_simple_powerpc_decoder_init(lzma_next_coder *next,
74 const lzma_allocator *allocator,
75 const lzma_filter_info *filters)
76 {
77 return powerpc_coder_init(next, allocator, filters, false);
78 }
79 #endif
80