1 /* GNU/Linux/ARM specific low level interface, for the remote server for GDB.
2    Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004
3    Free Software Foundation, Inc.
4 
5    This file is part of GDB.
6 
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 2 of the License, or
10    (at your option) any later version.
11 
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program; if not, write to the Free Software
19    Foundation, Inc., 59 Temple Place - Suite 330,
20    Boston, MA 02111-1307, USA.  */
21 
22 #include "server.h"
23 #include "linux-low.h"
24 
25 #ifdef HAVE_SYS_REG_H
26 #include <sys/reg.h>
27 #endif
28 
29 #define arm_num_regs 26
30 
31 static int arm_regmap[] = {
32   0, 4, 8, 12, 16, 20, 24, 28,
33   32, 36, 40, 44, 48, 52, 56, 60,
34   -1, -1, -1, -1, -1, -1, -1, -1, -1,
35   64
36 };
37 
38 static int
39 arm_cannot_store_register (int regno)
40 {
41   return (regno >= arm_num_regs);
42 }
43 
44 static int
45 arm_cannot_fetch_register (int regno)
46 {
47   return (regno >= arm_num_regs);
48 }
49 
50 extern int debug_threads;
51 
52 static CORE_ADDR
53 arm_get_pc ()
54 {
55   unsigned long pc;
56   collect_register_by_name ("pc", &pc);
57   if (debug_threads)
58     fprintf (stderr, "stop pc is %08lx\n", pc);
59   return pc;
60 }
61 
62 static void
63 arm_set_pc (CORE_ADDR pc)
64 {
65   unsigned long newpc = pc;
66   supply_register_by_name ("pc", &newpc);
67 }
68 
69 /* Correct in either endianness.  We do not support Thumb yet.  */
70 static const unsigned long arm_breakpoint = 0xef9f0001;
71 #define arm_breakpoint_len 4
72 
73 static int
74 arm_breakpoint_at (CORE_ADDR where)
75 {
76   unsigned long insn;
77 
78   (*the_target->read_memory) (where, (char *) &insn, 4);
79   if (insn == arm_breakpoint)
80     return 1;
81 
82   /* If necessary, recognize more trap instructions here.  GDB only uses the
83      one.  */
84   return 0;
85 }
86 
87 /* We only place breakpoints in empty marker functions, and thread locking
88    is outside of the function.  So rather than importing software single-step,
89    we can just run until exit.  */
90 static CORE_ADDR
91 arm_reinsert_addr ()
92 {
93   unsigned long pc;
94   collect_register_by_name ("lr", &pc);
95   return pc;
96 }
97 
98 struct linux_target_ops the_low_target = {
99   arm_num_regs,
100   arm_regmap,
101   arm_cannot_fetch_register,
102   arm_cannot_store_register,
103   arm_get_pc,
104   arm_set_pc,
105   (const char *) &arm_breakpoint,
106   arm_breakpoint_len,
107   arm_reinsert_addr,
108   0,
109   arm_breakpoint_at,
110 };
111