xref: /freebsd/contrib/xz/src/liblzma/simple/sparc.c (revision e9ac41698b2f322d55ccf9da50a3596edb2c1800)
1 // SPDX-License-Identifier: 0BSD
2 
3 ///////////////////////////////////////////////////////////////////////////////
4 //
5 /// \file       sparc.c
6 /// \brief      Filter for SPARC binaries
7 ///
8 //  Authors:    Igor Pavlov
9 //              Lasse Collin
10 //
11 ///////////////////////////////////////////////////////////////////////////////
12 
13 #include "simple_private.h"
14 
15 
16 static size_t
17 sparc_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 
24 		if ((buffer[i] == 0x40 && (buffer[i + 1] & 0xC0) == 0x00)
25 				|| (buffer[i] == 0x7F
26 				&& (buffer[i + 1] & 0xC0) == 0xC0)) {
27 
28 			uint32_t src = ((uint32_t)buffer[i + 0] << 24)
29 					| ((uint32_t)buffer[i + 1] << 16)
30 					| ((uint32_t)buffer[i + 2] << 8)
31 					| ((uint32_t)buffer[i + 3]);
32 
33 			src <<= 2;
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 			dest >>= 2;
42 
43 			dest = (((0 - ((dest >> 22) & 1)) << 22) & 0x3FFFFFFF)
44 					| (dest & 0x3FFFFF)
45 					| 0x40000000;
46 
47 			buffer[i + 0] = (uint8_t)(dest >> 24);
48 			buffer[i + 1] = (uint8_t)(dest >> 16);
49 			buffer[i + 2] = (uint8_t)(dest >> 8);
50 			buffer[i + 3] = (uint8_t)(dest);
51 		}
52 	}
53 
54 	return i;
55 }
56 
57 
58 static lzma_ret
59 sparc_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
60 		const lzma_filter_info *filters, bool is_encoder)
61 {
62 	return lzma_simple_coder_init(next, allocator, filters,
63 			&sparc_code, 0, 4, 4, is_encoder);
64 }
65 
66 
67 #ifdef HAVE_ENCODER_SPARC
68 extern lzma_ret
69 lzma_simple_sparc_encoder_init(lzma_next_coder *next,
70 		const lzma_allocator *allocator,
71 		const lzma_filter_info *filters)
72 {
73 	return sparc_coder_init(next, allocator, filters, true);
74 }
75 #endif
76 
77 
78 #ifdef HAVE_DECODER_SPARC
79 extern lzma_ret
80 lzma_simple_sparc_decoder_init(lzma_next_coder *next,
81 		const lzma_allocator *allocator,
82 		const lzma_filter_info *filters)
83 {
84 	return sparc_coder_init(next, allocator, filters, false);
85 }
86 #endif
87