1
2/*---------------------------------------------------------------*/
3/*--- begin                                libvex_guest_arm.h ---*/
4/*---------------------------------------------------------------*/
5
6/*
7   This file is part of Valgrind, a dynamic binary instrumentation
8   framework.
9
10   Copyright (C) 2004-2015 OpenWorks LLP
11      info@open-works.net
12
13   This program is free software; you can redistribute it and/or
14   modify it under the terms of the GNU General Public License as
15   published by the Free Software Foundation; either version 2 of the
16   License, or (at your option) any later version.
17
18   This program is distributed in the hope that it will be useful, but
19   WITHOUT ANY WARRANTY; without even the implied warranty of
20   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21   General Public License for more details.
22
23   You should have received a copy of the GNU General Public License
24   along with this program; if not, write to the Free Software
25   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
26   02110-1301, USA.
27
28   The GNU General Public License is contained in the file COPYING.
29*/
30
31#ifndef __LIBVEX_PUB_GUEST_ARM_H
32#define __LIBVEX_PUB_GUEST_ARM_H
33
34#include "libvex_basictypes.h"
35
36
37/*---------------------------------------------------------------*/
38/*--- Vex's representation of the ARM CPU state.              ---*/
39/*---------------------------------------------------------------*/
40
41typedef
42   struct {
43      /* 0 */
44      /* Event check fail addr and counter. */
45      UInt host_EvC_FAILADDR; /* 0 */
46      UInt host_EvC_COUNTER;  /* 4 */
47      UInt guest_R0;
48      UInt guest_R1;
49      UInt guest_R2;
50      UInt guest_R3;
51      UInt guest_R4;
52      UInt guest_R5;
53      UInt guest_R6;
54      UInt guest_R7;
55      UInt guest_R8;
56      UInt guest_R9;
57      UInt guest_R10;
58      UInt guest_R11;
59      UInt guest_R12;
60      UInt guest_R13;     /* stack pointer */
61      UInt guest_R14;     /* link register */
62      UInt guest_R15T;
63      /* program counter[31:1] ++ [T], encoding both the current
64         instruction address and the ARM vs Thumb state of the
65         machine.  T==1 is Thumb, T==0 is ARM.  Hence values of the
66         form X--(31)--X1 denote a Thumb instruction at location
67         X--(31)--X0, values of the form X--(30)--X00 denote an ARM
68         instruction at precisely that address, and values of the form
69         X--(30)--10 are invalid since they would imply an ARM
70         instruction at a non-4-aligned address. */
71
72      /* 4-word thunk used to calculate N(sign) Z(zero) C(carry,
73         unsigned overflow) and V(signed overflow) flags. */
74      /* 72 */
75      UInt guest_CC_OP;
76      UInt guest_CC_DEP1;
77      UInt guest_CC_DEP2;
78      UInt guest_CC_NDEP;
79
80      /* A 32-bit value which is used to compute the APSR.Q (sticky
81         saturation) flag, when necessary.  If the value stored here
82         is zero, APSR.Q is currently zero.  If it is any other value,
83         APSR.Q is currently one. */
84      UInt guest_QFLAG32;
85
86      /* 32-bit values to represent APSR.GE0 .. GE3.  Same
87         zero-vs-nonzero scheme as for QFLAG32. */
88      UInt guest_GEFLAG0;
89      UInt guest_GEFLAG1;
90      UInt guest_GEFLAG2;
91      UInt guest_GEFLAG3;
92
93      /* Various pseudo-regs mandated by Vex or Valgrind. */
94      /* Emulation notes */
95      UInt guest_EMNOTE;
96
97      /* For clinval/clflush: record start and length of area */
98      UInt guest_CMSTART;
99      UInt guest_CMLEN;
100
101      /* Used to record the unredirected guest address at the start of
102         a translation whose start has been redirected.  By reading
103         this pseudo-register shortly afterwards, the translation can
104         find out what the corresponding no-redirection address was.
105         Note, this is only set for wrap-style redirects, not for
106         replace-style ones. */
107      UInt guest_NRADDR;
108
109      /* Needed for Darwin (but mandated for all guest architectures):
110         program counter at the last syscall insn (int 0x80/81/82,
111         sysenter, syscall, svc).  Used when backing up to restart a
112         syscall that has been interrupted by a signal. */
113      /* 124 */
114      UInt guest_IP_AT_SYSCALL;
115
116      /* VFP state.  D0 .. D15 must be 8-aligned. */
117      /* 128 */
118      ULong guest_D0;
119      ULong guest_D1;
120      ULong guest_D2;
121      ULong guest_D3;
122      ULong guest_D4;
123      ULong guest_D5;
124      ULong guest_D6;
125      ULong guest_D7;
126      ULong guest_D8;
127      ULong guest_D9;
128      ULong guest_D10;
129      ULong guest_D11;
130      ULong guest_D12;
131      ULong guest_D13;
132      ULong guest_D14;
133      ULong guest_D15;
134      ULong guest_D16;
135      ULong guest_D17;
136      ULong guest_D18;
137      ULong guest_D19;
138      ULong guest_D20;
139      ULong guest_D21;
140      ULong guest_D22;
141      ULong guest_D23;
142      ULong guest_D24;
143      ULong guest_D25;
144      ULong guest_D26;
145      ULong guest_D27;
146      ULong guest_D28;
147      ULong guest_D29;
148      ULong guest_D30;
149      ULong guest_D31;
150      UInt  guest_FPSCR;
151
152      /* Not a town in Cornwall, but instead the TPIDRURO, on of the
153         Thread ID registers present in CP15 (the system control
154         coprocessor), register set "c13", register 3 (the User
155         Read-only Thread ID Register).  arm-linux apparently uses it
156         to hold the TLS pointer for the thread.  It's read-only in
157         user space.  On Linux it is set in user space by various
158         thread-related syscalls. */
159      UInt guest_TPIDRURO;
160
161      /* Representation of the Thumb IT state.  ITSTATE is a 32-bit
162         value with 4 8-bit lanes.  [7:0] pertain to the next insn to
163         execute, [15:8] for the one after that, etc.  The per-insn
164         update to ITSTATE is to unsignedly shift it right 8 bits,
165         hence introducing a zero byte for the furthest ahead
166         instruction.  As per the next para, a zero byte denotes the
167         condition ALWAYS.
168
169         Each byte lane has one of the two following formats:
170
171         cccc 0001  for an insn which is part of an IT block.  cccc is
172                    the guarding condition (standard ARM condition
173                    code) XORd with 0xE, so as to cause 'cccc == 0'
174                    to encode the condition ALWAYS.
175
176         0000 0000  for an insn which is not part of an IT block.
177
178         If the bottom 4 bits are zero then the top 4 must be too.
179
180         Given the byte lane for an instruction, the guarding
181         condition for the instruction is (((lane >> 4) & 0xF) ^ 0xE).
182         This is not as stupid as it sounds, because the front end
183         elides the shift.  And the am-I-in-an-IT-block check is
184         (lane != 0).
185
186         In the case where (by whatever means) we know at JIT time
187         that an instruction is not in an IT block, we can prefix its
188         IR with assignments ITSTATE = 0 and hence have iropt fold out
189         the testing code.
190
191         The condition "is outside or last in IT block" corresponds
192         to the top 24 bits of ITSTATE being zero.
193      */
194      UInt guest_ITSTATE;
195
196      /* Padding to make it have an 16-aligned size */
197      UInt padding1;
198   }
199   VexGuestARMState;
200
201
202/*---------------------------------------------------------------*/
203/*--- Utility functions for ARM guest stuff.                  ---*/
204/*---------------------------------------------------------------*/
205
206/* ALL THE FOLLOWING ARE VISIBLE TO LIBRARY CLIENT */
207
208/* Initialise all guest ARM state. */
209
210extern
211void LibVEX_GuestARM_initialise ( /*OUT*/VexGuestARMState* vex_state );
212
213/* Calculate the ARM flag state from the saved data. */
214
215extern
216UInt LibVEX_GuestARM_get_cpsr ( /*IN*/const VexGuestARMState* vex_state );
217
218
219#endif /* ndef __LIBVEX_PUB_GUEST_ARM_H */
220
221
222/*---------------------------------------------------------------*/
223/*---                                      libvex_guest_arm.h ---*/
224/*---------------------------------------------------------------*/
225