1/*
2 * Copyright (c) 2012-2014 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder. You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2012 Google
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Gabe Black
41 */
42
43#include "arch/arm/decoder.hh"
44#include "arch/arm/isa_traits.hh"
45#include "arch/arm/utility.hh"
46#include "base/trace.hh"
47#include "debug/Decoder.hh"
48
49namespace ArmISA
50{
51
52GenericISA::BasicDecodeCache Decoder::defaultCache;
53
54Decoder::Decoder()
55 : data(0), fpscrLen(0), fpscrStride(0)
56{
57 reset();
58}
59
60void
61Decoder::reset()
62{
63 bigThumb = false;
64 offset = 0;
65 emi = 0;
66 instDone = false;
67 outOfBytes = true;
68 foundIt = false;
69}
70
71void
72Decoder::process()
73{
74 // emi is typically ready, with some caveats below...
75 instDone = true;
76
77 if (!emi.thumb) {
78 emi.instBits = data;
79 if (!emi.aarch64) {
80 emi.sevenAndFour = bits(data, 7) && bits(data, 4);
81 emi.isMisc = (bits(data, 24, 23) == 0x2 &&
82 bits(data, 20) == 0);
83 }
84 consumeBytes(4);
85 DPRINTF(Decoder, "Arm inst: %#x.\n", (uint64_t)emi);
86 } else {
87 uint16_t word = (data >> (offset * 8));
88 if (bigThumb) {
89 // A 32 bit thumb inst is half collected.
90 emi.instBits = emi.instBits | word;
91 bigThumb = false;
92 consumeBytes(2);
93 DPRINTF(Decoder, "Second half of 32 bit Thumb: %#x.\n",
94 emi.instBits);
95 } else {
96 uint16_t highBits = word & 0xF800;
97 if (highBits == 0xE800 || highBits == 0xF000 ||
98 highBits == 0xF800) {
99 // The start of a 32 bit thumb inst.
100 emi.bigThumb = 1;
101 if (offset == 0) {
102 // We've got the whole thing.
103 emi.instBits = (data >> 16) | (data << 16);
104 DPRINTF(Decoder, "All of 32 bit Thumb: %#x.\n",
105 emi.instBits);
106 consumeBytes(4);
107 } else {
108 // We only have the first half word.
109 DPRINTF(Decoder,
110 "First half of 32 bit Thumb.\n");
111 emi.instBits = (uint32_t)word << 16;
112 bigThumb = true;
113 consumeBytes(2);
114 // emi not ready yet.
115 instDone = false;
116 }
117 } else {
118 // A 16 bit thumb inst.
119 consumeBytes(2);
120 emi.instBits = word;
121 // Set the condition code field artificially.
122 emi.condCode = COND_UC;
123 DPRINTF(Decoder, "16 bit Thumb: %#x.\n",
124 emi.instBits);
125 if (bits(word, 15, 8) == 0xbf &&
126 bits(word, 3, 0) != 0x0) {
127 foundIt = true;
128 itBits = bits(word, 7, 0);
129 DPRINTF(Decoder,
130 "IT detected, cond = %#x, mask = %#x\n",
131 itBits.cond, itBits.mask);
132 }
133 }
134 }
135 }
136}
137
138void
139Decoder::consumeBytes(int numBytes)
140{
141 offset += numBytes;
| 1/*
2 * Copyright (c) 2012-2014 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder. You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2012 Google
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Gabe Black
41 */
42
43#include "arch/arm/decoder.hh"
44#include "arch/arm/isa_traits.hh"
45#include "arch/arm/utility.hh"
46#include "base/trace.hh"
47#include "debug/Decoder.hh"
48
49namespace ArmISA
50{
51
52GenericISA::BasicDecodeCache Decoder::defaultCache;
53
54Decoder::Decoder()
55 : data(0), fpscrLen(0), fpscrStride(0)
56{
57 reset();
58}
59
60void
61Decoder::reset()
62{
63 bigThumb = false;
64 offset = 0;
65 emi = 0;
66 instDone = false;
67 outOfBytes = true;
68 foundIt = false;
69}
70
71void
72Decoder::process()
73{
74 // emi is typically ready, with some caveats below...
75 instDone = true;
76
77 if (!emi.thumb) {
78 emi.instBits = data;
79 if (!emi.aarch64) {
80 emi.sevenAndFour = bits(data, 7) && bits(data, 4);
81 emi.isMisc = (bits(data, 24, 23) == 0x2 &&
82 bits(data, 20) == 0);
83 }
84 consumeBytes(4);
85 DPRINTF(Decoder, "Arm inst: %#x.\n", (uint64_t)emi);
86 } else {
87 uint16_t word = (data >> (offset * 8));
88 if (bigThumb) {
89 // A 32 bit thumb inst is half collected.
90 emi.instBits = emi.instBits | word;
91 bigThumb = false;
92 consumeBytes(2);
93 DPRINTF(Decoder, "Second half of 32 bit Thumb: %#x.\n",
94 emi.instBits);
95 } else {
96 uint16_t highBits = word & 0xF800;
97 if (highBits == 0xE800 || highBits == 0xF000 ||
98 highBits == 0xF800) {
99 // The start of a 32 bit thumb inst.
100 emi.bigThumb = 1;
101 if (offset == 0) {
102 // We've got the whole thing.
103 emi.instBits = (data >> 16) | (data << 16);
104 DPRINTF(Decoder, "All of 32 bit Thumb: %#x.\n",
105 emi.instBits);
106 consumeBytes(4);
107 } else {
108 // We only have the first half word.
109 DPRINTF(Decoder,
110 "First half of 32 bit Thumb.\n");
111 emi.instBits = (uint32_t)word << 16;
112 bigThumb = true;
113 consumeBytes(2);
114 // emi not ready yet.
115 instDone = false;
116 }
117 } else {
118 // A 16 bit thumb inst.
119 consumeBytes(2);
120 emi.instBits = word;
121 // Set the condition code field artificially.
122 emi.condCode = COND_UC;
123 DPRINTF(Decoder, "16 bit Thumb: %#x.\n",
124 emi.instBits);
125 if (bits(word, 15, 8) == 0xbf &&
126 bits(word, 3, 0) != 0x0) {
127 foundIt = true;
128 itBits = bits(word, 7, 0);
129 DPRINTF(Decoder,
130 "IT detected, cond = %#x, mask = %#x\n",
131 itBits.cond, itBits.mask);
132 }
133 }
134 }
135 }
136}
137
138void
139Decoder::consumeBytes(int numBytes)
140{
141 offset += numBytes;
|