isa_traits.hh revision 7580:6f77f379a594 
1/*
2 * Copyright (c) 2010 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) 2003-2005 The Regents of The University of Michigan
15 * Copyright (c) 2007-2008 The Florida State University
16 * All rights reserved.
17 *
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions are
20 * met: redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer;
22 * redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution;
25 * neither the name of the copyright holders nor the names of its
26 * contributors may be used to endorse or promote products derived from
27 * this software without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
30 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
31 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
32 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
33 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
34 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
35 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
39 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
40 *
41 * Authors: Gabe Black
42 *          Stephen Hines
43 */
44
45#ifndef __ARCH_ARM_ISA_TRAITS_HH__
46#define __ARCH_ARM_ISA_TRAITS_HH__
47
48#include "arch/arm/types.hh"
49#include "base/types.hh"
50
51namespace LittleEndianGuest {};
52
53#define TARGET_ARM
54
55class StaticInstPtr;
56
57namespace ArmISA
58{
59    using namespace LittleEndianGuest;
60
61    StaticInstPtr decodeInst(ExtMachInst);
62
63    // ARM DOES NOT have a delay slot
64    #define ISA_HAS_DELAY_SLOT 0
65
66    const Addr PageShift = 12;
67    const Addr PageBytes = ULL(1) << PageShift;
68    const Addr Page_Mask = ~(PageBytes - 1);
69    const Addr PageOffset = PageBytes - 1;
70
71
72    ////////////////////////////////////////////////////////////////////////
73    //
74    //  Translation stuff
75    //
76
77    const Addr PteShift = 3;
78    const Addr NPtePageShift = PageShift - PteShift;
79    const Addr NPtePage = ULL(1) << NPtePageShift;
80    const Addr PteMask = NPtePage - 1;
81
82    //// All 'Mapped' segments go through the TLB
83    //// All other segments are translated by dropping the MSB, to give
84    //// the corresponding physical address
85    // User Segment - Mapped
86    const Addr USegBase = ULL(0x0);
87    const Addr USegEnd = ULL(0x7FFFFFFF);
88
89    // Kernel Segment 0 - Unmapped
90    const Addr KSeg0End = ULL(0x9FFFFFFF);
91    const Addr KSeg0Base =  ULL(0x80000000);
92    const Addr KSeg0Mask = ULL(0x1FFFFFFF);
93
94    const unsigned VABits = 32;
95    const unsigned PABits = 32; // Is this correct?
96    const Addr VAddrImplMask = (ULL(1) << VABits) - 1;
97    const Addr VAddrUnImplMask = ~VAddrImplMask;
98    inline Addr VAddrImpl(Addr a) { return a & VAddrImplMask; }
99    inline Addr VAddrVPN(Addr a) { return a >> ArmISA::PageShift; }
100    inline Addr VAddrOffset(Addr a) { return a & ArmISA::PageOffset; }
101
102    const Addr PAddrImplMask = (ULL(1) << PABits) - 1;
103
104    // return a no-op instruction... used for instruction fetch faults
105    const ExtMachInst NoopMachInst = 0x00000000;
106
107    const int LogVMPageSize = 12;	// 4K bytes
108    const int VMPageSize = (1 << LogVMPageSize);
109
110    // Shouldn't this be 1 because of Thumb?! Dynamic? --Ali
111    const int BranchPredAddrShiftAmt = 2; // instructions are 4-byte aligned
112
113    const int MachineBytes = 4;
114    const int WordBytes = 4;
115    const int HalfwordBytes = 2;
116    const int ByteBytes = 1;
117
118    const uint32_t HighVecs = 0xFFFF0000;
119
120    // Memory accesses cannot be unaligned
121    const bool HasUnalignedMemAcc = false;
122
123    enum InterruptTypes
124    {
125        INT_RST,
126        INT_ABT,
127        INT_IRQ,
128        INT_FIQ,
129        NumInterruptTypes
130    };
131
132    // These otherwise unused bits of the PC are used to select a mode
133    // like the J and T bits of the CPSR.
134    static const Addr PcJBitShift = 33;
135    static const Addr PcTBitShift = 34;
136    static const Addr PcModeMask = (ULL(1) << PcJBitShift) |
137                                   (ULL(1) << PcTBitShift);
138};
139
140using namespace ArmISA;
141
142#endif // __ARCH_ARM_ISA_TRAITS_HH__
143