1 // SPDX-License-Identifier: 0BSD
2
3 ///////////////////////////////////////////////////////////////////////////////
4 //
5 /// \file arm.c
6 /// \brief Filter for ARM binaries
7 ///
8 // Authors: Igor Pavlov
9 // Lasse Collin
10 //
11 ///////////////////////////////////////////////////////////////////////////////
12
13 #include "simple_private.h"
14
15
16 static size_t
arm_code(void * simple lzma_attribute ((__unused__)),uint32_t now_pos,bool is_encoder,uint8_t * buffer,size_t size)17 arm_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 if (buffer[i + 3] == 0xEB) {
24 uint32_t src = ((uint32_t)(buffer[i + 2]) << 16)
25 | ((uint32_t)(buffer[i + 1]) << 8)
26 | (uint32_t)(buffer[i + 0]);
27 src <<= 2;
28
29 uint32_t dest;
30 if (is_encoder)
31 dest = now_pos + (uint32_t)(i) + 8 + src;
32 else
33 dest = src - (now_pos + (uint32_t)(i) + 8);
34
35 dest >>= 2;
36 buffer[i + 2] = (dest >> 16);
37 buffer[i + 1] = (dest >> 8);
38 buffer[i + 0] = dest;
39 }
40 }
41
42 return i;
43 }
44
45
46 static lzma_ret
arm_coder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters,bool is_encoder)47 arm_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
48 const lzma_filter_info *filters, bool is_encoder)
49 {
50 return lzma_simple_coder_init(next, allocator, filters,
51 &arm_code, 0, 4, 4, is_encoder);
52 }
53
54
55 #ifdef HAVE_ENCODER_ARM
56 extern lzma_ret
lzma_simple_arm_encoder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters)57 lzma_simple_arm_encoder_init(lzma_next_coder *next,
58 const lzma_allocator *allocator,
59 const lzma_filter_info *filters)
60 {
61 return arm_coder_init(next, allocator, filters, true);
62 }
63 #endif
64
65
66 #ifdef HAVE_DECODER_ARM
67 extern lzma_ret
lzma_simple_arm_decoder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters)68 lzma_simple_arm_decoder_init(lzma_next_coder *next,
69 const lzma_allocator *allocator,
70 const lzma_filter_info *filters)
71 {
72 return arm_coder_init(next, allocator, filters, false);
73 }
74 #endif
75