1/* Low level interface to valgrind, for the remote server for GDB integrated
2   in valgrind.
3   Copyright (C) 2011
4   Free Software Foundation, Inc.
5
6   This file is part of VALGRIND.
7   It has been inspired from a file from gdbserver in gdb 6.6.
8
9   This program is free software; you can redistribute it and/or modify
10   it under the terms of the GNU General Public License as published by
11   the Free Software Foundation; either version 2 of the License, or
12   (at your option) any later version.
13
14   This program is distributed in the hope that it will be useful,
15   but WITHOUT ANY WARRANTY; without even the implied warranty of
16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17   GNU General Public License for more details.
18
19   You should have received a copy of the GNU General Public License
20   along with this program; if not, write to the Free Software
21   Foundation, Inc., 51 Franklin Street, Fifth Floor,
22   Boston, MA 02110-1301, USA.  */
23
24#include "server.h"
25#include "target.h"
26#include "regdef.h"
27#include "regcache.h"
28
29#include "pub_core_aspacemgr.h"
30#include "pub_tool_machine.h"
31#include "pub_core_threadstate.h"
32#include "pub_core_transtab.h"
33#include "pub_core_gdbserver.h"
34#include "pub_core_debuginfo.h"
35
36#include "valgrind_low.h"
37
38#include "libvex_guest_arm.h"
39
40struct reg regs[] = {
41  { "r0", 0, 32 },
42  { "r1", 32, 32 },
43  { "r2", 64, 32 },
44  { "r3", 96, 32 },
45  { "r4", 128, 32 },
46  { "r5", 160, 32 },
47  { "r6", 192, 32 },
48  { "r7", 224, 32 },
49  { "r8", 256, 32 },
50  { "r9", 288, 32 },
51  { "r10", 320, 32 },
52  { "r11", 352, 32 },
53  { "r12", 384, 32 },
54  { "sp", 416, 32 },
55  { "lr", 448, 32 },
56  { "pc", 480, 32 },
57  { "", 512, 0 }, // It seems these entries are needed
58  { "", 512, 0 }, // as previous versions of arm <-> gdb placed
59  { "", 512, 0 }, // some floating point registers here. So, cpsr
60  { "", 512, 0 }, // must be register 25.
61  { "", 512, 0 },
62  { "", 512, 0 },
63  { "", 512, 0 },
64  { "", 512, 0 },
65  { "", 512, 0 },
66  { "cpsr", 512, 32 },
67  { "d0", 544, 64 },
68  { "d1", 608, 64 },
69  { "d2", 672, 64 },
70  { "d3", 736, 64 },
71  { "d4", 800, 64 },
72  { "d5", 864, 64 },
73  { "d6", 928, 64 },
74  { "d7", 992, 64 },
75  { "d8", 1056, 64 },
76  { "d9", 1120, 64 },
77  { "d10", 1184, 64 },
78  { "d11", 1248, 64 },
79  { "d12", 1312, 64 },
80  { "d13", 1376, 64 },
81  { "d14", 1440, 64 },
82  { "d15", 1504, 64 },
83  { "d16", 1568, 64 },
84  { "d17", 1632, 64 },
85  { "d18", 1696, 64 },
86  { "d19", 1760, 64 },
87  { "d20", 1824, 64 },
88  { "d21", 1888, 64 },
89  { "d22", 1952, 64 },
90  { "d23", 2016, 64 },
91  { "d24", 2080, 64 },
92  { "d25", 2144, 64 },
93  { "d26", 2208, 64 },
94  { "d27", 2272, 64 },
95  { "d28", 2336, 64 },
96  { "d29", 2400, 64 },
97  { "d30", 2464, 64 },
98  { "d31", 2528, 64 },
99  { "fpscr", 2592, 32 }
100};
101static const char *expedite_regs[] = { "r11", "sp", "pc", 0 };
102#define num_regs (sizeof (regs) / sizeof (regs[0]))
103
104static
105CORE_ADDR get_pc (void)
106{
107   unsigned long pc;
108
109   collect_register_by_name ("pc", &pc);
110
111   dlog(1, "stop pc is %p\n", (void *) pc);
112   return pc;
113}
114
115static
116void set_pc (CORE_ADDR newpc)
117{
118   Bool mod;
119   supply_register_by_name ("pc", &newpc, &mod);
120   if (mod)
121      dlog(1, "set pc to %p\n", C2v (newpc));
122   else
123      dlog(1, "set pc not changed %p\n", C2v (newpc));
124}
125
126Addr thumb_pc (Addr pc)
127{
128   // If the thumb bit (bit 0) is already set, we trust it.
129   if (pc & 1) {
130      dlog (1, "%p = thumb (bit0 is set)\n", C2v (pc));
131      return pc;
132   }
133
134   // Here, bit 0 is not set.
135   // For a pc aligned on 4 bytes, we have to use the debug
136   // info to determine the thumb-ness.
137   // else (aligned on 2 bytes), we trust this is a thumb
138   // address and we set the thumb bit.
139
140   if (pc & 2) {
141      dlog (1, "bit0 not set, bit1 set => %p = thumb\n", C2v (pc));
142      return pc | 1;
143   }
144
145   // pc aligned on 4 bytes. We need to use debug info.
146   {
147      Char fnname[200]; // ??? max size
148      Addr entrypoint;
149      Addr ptoc; // unused but needed.
150      // If this is a thumb instruction, we need to ask
151      // the debug info with the bit0 set
152      // (why can't debug info do that for us ???)
153      // (why if this is a 4 bytes thumb instruction ???)
154      if (VG_(get_fnname_raw) (pc | 1, fnname, 200)) {
155         if (VG_(lookup_symbol_SLOW)( "*", fnname, &entrypoint, &ptoc )) {
156            dlog (1, "fnname %s lookupsym %p => %p %s.\n",
157                  fnname, C2v(entrypoint), C2v(pc),
158                  (entrypoint & 1 ? "thumb" : "arm"));
159            if (entrypoint & 1)
160               return pc | 1;
161            else
162               return pc;
163
164         } else {
165            dlog (1, "%p fnname %s lookupsym failed?. Assume arm\n",
166                  C2v (pc), fnname);
167            return pc;
168         }
169      } else {
170         // Can't find function name. We assume this is arm
171         dlog (1, "%p unknown fnname?. Assume arm\n", C2v (pc));
172         return pc;
173      }
174   }
175}
176
177/* store registers in the guest state (gdbserver_to_valgrind)
178   or fetch register from the guest state (valgrind_to_gdbserver). */
179static
180void transfer_register (ThreadId tid, int abs_regno, void * buf,
181                        transfer_direction dir, int size, Bool *mod)
182{
183   ThreadState* tst = VG_(get_ThreadState)(tid);
184   int set = abs_regno / num_regs;
185   int regno = abs_regno % num_regs;
186   *mod = False;
187
188   VexGuestARMState* arm = (VexGuestARMState*) get_arch (set, tst);
189
190   switch (regno) {
191   // numbers here have to match the order of regs above
192   // Attention: gdb order does not match valgrind order.
193   case 0:  VG_(transfer) (&arm->guest_R0,   buf, dir, size, mod); break;
194   case 1:  VG_(transfer) (&arm->guest_R1,   buf, dir, size, mod); break;
195   case 2:  VG_(transfer) (&arm->guest_R2,   buf, dir, size, mod); break;
196   case 3:  VG_(transfer) (&arm->guest_R3,   buf, dir, size, mod); break;
197   case 4:  VG_(transfer) (&arm->guest_R4,   buf, dir, size, mod); break;
198   case 5:  VG_(transfer) (&arm->guest_R5,   buf, dir, size, mod); break;
199   case 6:  VG_(transfer) (&arm->guest_R6,   buf, dir, size, mod); break;
200   case 7:  VG_(transfer) (&arm->guest_R7,   buf, dir, size, mod); break;
201   case 8:  VG_(transfer) (&arm->guest_R8,   buf, dir, size, mod); break;
202   case 9:  VG_(transfer) (&arm->guest_R9,   buf, dir, size, mod); break;
203   case 10: VG_(transfer) (&arm->guest_R10,  buf, dir, size, mod); break;
204   case 11: VG_(transfer) (&arm->guest_R11,  buf, dir, size, mod); break;
205   case 12: VG_(transfer) (&arm->guest_R12,  buf, dir, size, mod); break;
206   case 13: VG_(transfer) (&arm->guest_R13,  buf, dir, size, mod); break;
207   case 14: VG_(transfer) (&arm->guest_R14,  buf, dir, size, mod); break;
208   case 15: {
209      VG_(transfer) (&arm->guest_R15T, buf, dir, size, mod);
210      if (dir == gdbserver_to_valgrind && *mod) {
211         // If gdb is changing the PC, we have to set the thumb bit
212         // if needed.
213         arm->guest_R15T = thumb_pc(arm->guest_R15T);
214      }
215      break;
216   }
217   case 16:
218   case 17:
219   case 18:
220   case 19:
221   case 20: /* 9 "empty registers". See struct reg regs above. */
222   case 21:
223   case 22:
224   case 23:
225   case 24: *mod = False; break;
226   case 25: {
227      UInt cpsr = LibVEX_GuestARM_get_cpsr (arm);
228      if (dir == valgrind_to_gdbserver) {
229         VG_(transfer) (&cpsr, buf, dir, size, mod);
230      } else {
231#      if 0
232         UInt newcpsr;
233         VG_(transfer) (&newcpsr, buf, dir, size, mod);
234         *mod = newcpsr != cpsr;
235         // GDBTD ???? see FIXME in guest_arm_helpers.c
236         LibVEX_GuestARM_put_flags (newcpsr, arm);
237#      else
238         *mod = False;
239#      endif
240      }
241      break;
242   }
243   case 26: VG_(transfer) (&arm->guest_D0,  buf, dir, size, mod); break;
244   case 27: VG_(transfer) (&arm->guest_D1,  buf, dir, size, mod); break;
245   case 28: VG_(transfer) (&arm->guest_D2,  buf, dir, size, mod); break;
246   case 29: VG_(transfer) (&arm->guest_D3,  buf, dir, size, mod); break;
247   case 30: VG_(transfer) (&arm->guest_D4,  buf, dir, size, mod); break;
248   case 31: VG_(transfer) (&arm->guest_D5,  buf, dir, size, mod); break;
249   case 32: VG_(transfer) (&arm->guest_D6,  buf, dir, size, mod); break;
250   case 33: VG_(transfer) (&arm->guest_D7,  buf, dir, size, mod); break;
251   case 34: VG_(transfer) (&arm->guest_D8,  buf, dir, size, mod); break;
252   case 35: VG_(transfer) (&arm->guest_D9,  buf, dir, size, mod); break;
253   case 36: VG_(transfer) (&arm->guest_D10, buf, dir, size, mod); break;
254   case 37: VG_(transfer) (&arm->guest_D11, buf, dir, size, mod); break;
255   case 38: VG_(transfer) (&arm->guest_D12, buf, dir, size, mod); break;
256   case 39: VG_(transfer) (&arm->guest_D13, buf, dir, size, mod); break;
257   case 40: VG_(transfer) (&arm->guest_D14, buf, dir, size, mod); break;
258   case 41: VG_(transfer) (&arm->guest_D15, buf, dir, size, mod); break;
259   case 42: VG_(transfer) (&arm->guest_D16, buf, dir, size, mod); break;
260   case 43: VG_(transfer) (&arm->guest_D17, buf, dir, size, mod); break;
261   case 44: VG_(transfer) (&arm->guest_D18, buf, dir, size, mod); break;
262   case 45: VG_(transfer) (&arm->guest_D19, buf, dir, size, mod); break;
263   case 46: VG_(transfer) (&arm->guest_D20, buf, dir, size, mod); break;
264   case 47: VG_(transfer) (&arm->guest_D21, buf, dir, size, mod); break;
265   case 48: VG_(transfer) (&arm->guest_D22, buf, dir, size, mod); break;
266   case 49: VG_(transfer) (&arm->guest_D23, buf, dir, size, mod); break;
267   case 50: VG_(transfer) (&arm->guest_D24, buf, dir, size, mod); break;
268   case 51: VG_(transfer) (&arm->guest_D25, buf, dir, size, mod); break;
269   case 52: VG_(transfer) (&arm->guest_D26, buf, dir, size, mod); break;
270   case 53: VG_(transfer) (&arm->guest_D27, buf, dir, size, mod); break;
271   case 54: VG_(transfer) (&arm->guest_D28, buf, dir, size, mod); break;
272   case 55: VG_(transfer) (&arm->guest_D29, buf, dir, size, mod); break;
273   case 56: VG_(transfer) (&arm->guest_D30, buf, dir, size, mod); break;
274   case 57: VG_(transfer) (&arm->guest_D31, buf, dir, size, mod); break;
275   case 58: VG_(transfer) (&arm->guest_FPSCR, buf, dir, size, mod); break;
276   default: vg_assert(0);
277   }
278}
279
280static struct valgrind_target_ops low_target = {
281   num_regs,
282   regs,
283   13, //SP
284   transfer_register,
285   get_pc,
286   set_pc,
287   "arm",
288   "arm-with-vfpv3.xml",
289   "arm-with-vfpv3-valgrind.xml"
290};
291
292void arm_init_architecture (struct valgrind_target_ops *target)
293{
294   *target = low_target;
295   set_register_cache (regs, num_regs);
296   gdbserver_expedite_regs = expedite_regs;
297}
298