xref: /dragonfly/contrib/gdb-7/gdb/i386bsd-tdep.c (revision 73e0051e)
1 /* Target-dependent code for i386 BSD's.
2 
3    Copyright (C) 2001, 2002, 2003, 2004, 2007, 2008, 2009
4    Free Software Foundation, Inc.
5 
6    This file is part of GDB.
7 
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 3 of the License, or
11    (at your option) any later version.
12 
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
20 
21 #include "defs.h"
22 #include "arch-utils.h"
23 #include "frame.h"
24 #include "gdbcore.h"
25 #include "regcache.h"
26 #include "osabi.h"
27 
28 #include "gdb_string.h"
29 
30 #include "i386-tdep.h"
31 
32 /* Support for signal handlers.  */
33 
34 /* Assuming THIS_FRAME is for a BSD sigtramp routine, return the
35    address of the associated sigcontext structure.  */
36 
37 static CORE_ADDR
38 i386bsd_sigcontext_addr (struct frame_info *this_frame)
39 {
40   struct gdbarch *gdbarch = get_frame_arch (this_frame);
41   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
42   gdb_byte buf[4];
43   CORE_ADDR sp;
44 
45   get_frame_register (this_frame, I386_ESP_REGNUM, buf);
46   sp = extract_unsigned_integer (buf, 4, byte_order);
47 
48   return read_memory_unsigned_integer (sp + 8, 4, byte_order);
49 }
50 
51 
52 /* Support for shared libraries.  */
53 
54 /* Traditional BSD (4.3 BSD, still used for BSDI and 386BSD).  */
55 
56 /* From <machine/signal.h>.  */
57 int i386bsd_sc_reg_offset[] =
58 {
59   -1,				/* %eax */
60   -1,				/* %ecx */
61   -1,				/* %edx */
62   -1,				/* %ebx */
63   8 + 0 * 4,			/* %esp */
64   8 + 1 * 4,			/* %ebp */
65   -1,				/* %esi */
66   -1,				/* %edi */
67   8 + 3 * 4,			/* %eip */
68   8 + 4 * 4,			/* %eflags */
69   -1,				/* %cs */
70   -1,				/* %ss */
71   -1,				/* %ds */
72   -1,				/* %es */
73   -1,				/* %fs */
74   -1				/* %gs */
75 };
76 
77 void
78 i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
79 {
80   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
81 
82   tdep->jb_pc_offset = 0;
83 
84   tdep->sigtramp_start = 0xfdbfdfc0;
85   tdep->sigtramp_end = 0xfdbfe000;
86   tdep->sigcontext_addr = i386bsd_sigcontext_addr;
87   tdep->sc_reg_offset = i386bsd_sc_reg_offset;
88   tdep->sc_num_regs = ARRAY_SIZE (i386bsd_sc_reg_offset);
89 }
90 
91 
92 static enum gdb_osabi
93 i386bsd_aout_osabi_sniffer (bfd *abfd)
94 {
95   if (strcmp (bfd_get_target (abfd), "a.out-i386-netbsd") == 0)
96     return GDB_OSABI_NETBSD_AOUT;
97 
98   if (strcmp (bfd_get_target (abfd), "a.out-i386-freebsd") == 0)
99     return GDB_OSABI_FREEBSD_AOUT;
100 
101   return GDB_OSABI_UNKNOWN;
102 }
103 
104 static enum gdb_osabi
105 i386bsd_core_osabi_sniffer (bfd *abfd)
106 {
107   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
108     return GDB_OSABI_NETBSD_AOUT;
109 
110   return GDB_OSABI_UNKNOWN;
111 }
112 
113 
114 /* Provide a prototype to silence -Wmissing-prototypes.  */
115 void _initialize_i386bsd_tdep (void);
116 
117 void
118 _initialize_i386bsd_tdep (void)
119 {
120   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_aout_flavour,
121 				  i386bsd_aout_osabi_sniffer);
122 
123   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
124   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_unknown_flavour,
125 				  i386bsd_core_osabi_sniffer);
126 }
127