summaryrefslogtreecommitdiffstats
path: root/src/liblzma/simple/arm.c
blob: 6e53970d2f27349e063f8ef1f7d63923611772f2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
///////////////////////////////////////////////////////////////////////////////
//
/// \file       arm.c
/// \brief      Filter for ARM binaries
///
//  Authors:    Igor Pavlov
//              Lasse Collin
//
//  This file has been put into the public domain.
//  You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////

#include "simple_private.h"


static size_t
arm_code(void *simple lzma_attribute((__unused__)),
		uint32_t now_pos, bool is_encoder,
		uint8_t *buffer, size_t size)
{
	size_t i;
	for (i = 0; i + 4 <= size; i += 4) {
		if (buffer[i + 3] == 0xEB) {
			uint32_t src = ((uint32_t)(buffer[i + 2]) << 16)
					| ((uint32_t)(buffer[i + 1]) << 8)
					| (uint32_t)(buffer[i + 0]);
			src <<= 2;

			uint32_t dest;
			if (is_encoder)
				dest = now_pos + (uint32_t)(i) + 8 + src;
			else
				dest = src - (now_pos + (uint32_t)(i) + 8);

			dest >>= 2;
			buffer[i + 2] = (dest >> 16);
			buffer[i + 1] = (dest >> 8);
			buffer[i + 0] = dest;
		}
	}

	return i;
}


static lzma_ret
arm_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
		const lzma_filter_info *filters, bool is_encoder)
{
	return lzma_simple_coder_init(next, allocator, filters,
			&arm_code, 0, 4, 4, is_encoder);
}


#ifdef HAVE_ENCODER_ARM
extern lzma_ret
lzma_simple_arm_encoder_init(lzma_next_coder *next,
		const lzma_allocator *allocator,
		const lzma_filter_info *filters)
{
	return arm_coder_init(next, allocator, filters, true);
}
#endif


#ifdef HAVE_DECODER_ARM
extern lzma_ret
lzma_simple_arm_decoder_init(lzma_next_coder *next,
		const lzma_allocator *allocator,
		const lzma_filter_info *filters)
{
	return arm_coder_init(next, allocator, filters, false);
}
#endif