1 ///////////////////////////////////////////////////////////////////////////////
2 //
3 /// \file arm.c
4 /// \brief Filter for ARM 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
arm_code(void * simple lzma_attribute ((__unused__)),uint32_t now_pos,bool is_encoder,uint8_t * buffer,size_t size)18 arm_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 if (buffer[i + 3] == 0xEB) {
25 uint32_t src = (buffer[i + 2] << 16)
26 | (buffer[i + 1] << 8)
27 | (buffer[i + 0]);
28 src <<= 2;
29
30 uint32_t dest;
31 if (is_encoder)
32 dest = now_pos + (uint32_t)(i) + 8 + src;
33 else
34 dest = src - (now_pos + (uint32_t)(i) + 8);
35
36 dest >>= 2;
37 buffer[i + 2] = (dest >> 16);
38 buffer[i + 1] = (dest >> 8);
39 buffer[i + 0] = dest;
40 }
41 }
42
43 return i;
44 }
45
46
47 static lzma_ret
arm_coder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters,bool is_encoder)48 arm_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
49 const lzma_filter_info *filters, bool is_encoder)
50 {
51 return lzma_simple_coder_init(next, allocator, filters,
52 &arm_code, 0, 4, 4, is_encoder);
53 }
54
55
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
64
65 extern lzma_ret
lzma_simple_arm_decoder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_filter_info * filters)66 lzma_simple_arm_decoder_init(lzma_next_coder *next,
67 const lzma_allocator *allocator,
68 const lzma_filter_info *filters)
69 {
70 return arm_coder_init(next, allocator, filters, false);
71 }
72