1 /* Target-dependent code for i386 BSD's.
2 
3    Copyright (C) 2001-2013 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 3 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, see <http://www.gnu.org/licenses/>.  */
19 
20 #include "defs.h"
21 #include "arch-utils.h"
22 #include "frame.h"
23 #include "gdbcore.h"
24 #include "regcache.h"
25 #include "osabi.h"
26 
27 #include "gdb_string.h"
28 
29 #include "i386-tdep.h"
30 
31 /* Support for signal handlers.  */
32 
33 /* Assuming THIS_FRAME is for a BSD sigtramp routine, return the
34    address of the associated sigcontext structure.  */
35 
36 static CORE_ADDR
i386bsd_sigcontext_addr(struct frame_info * this_frame)37 i386bsd_sigcontext_addr (struct frame_info *this_frame)
38 {
39   struct gdbarch *gdbarch = get_frame_arch (this_frame);
40   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
41   gdb_byte buf[4];
42   CORE_ADDR sp;
43 
44   get_frame_register (this_frame, I386_ESP_REGNUM, buf);
45   sp = extract_unsigned_integer (buf, 4, byte_order);
46 
47   return read_memory_unsigned_integer (sp + 8, 4, byte_order);
48 }
49 
50 
51 /* Support for shared libraries.  */
52 
53 /* Traditional BSD (4.3 BSD, still used for BSDI and 386BSD).  */
54 
55 /* From <machine/signal.h>.  */
56 int i386bsd_sc_reg_offset[] =
57 {
58   -1,				/* %eax */
59   -1,				/* %ecx */
60   -1,				/* %edx */
61   -1,				/* %ebx */
62   8 + 0 * 4,			/* %esp */
63   8 + 1 * 4,			/* %ebp */
64   -1,				/* %esi */
65   -1,				/* %edi */
66   8 + 3 * 4,			/* %eip */
67   8 + 4 * 4,			/* %eflags */
68   -1,				/* %cs */
69   -1,				/* %ss */
70   -1,				/* %ds */
71   -1,				/* %es */
72   -1,				/* %fs */
73   -1				/* %gs */
74 };
75 
76 void
i386bsd_init_abi(struct gdbarch_info info,struct gdbarch * gdbarch)77 i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
78 {
79   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
80 
81   tdep->jb_pc_offset = 0;
82 
83   tdep->sigtramp_start = 0xfdbfdfc0;
84   tdep->sigtramp_end = 0xfdbfe000;
85   tdep->sigcontext_addr = i386bsd_sigcontext_addr;
86   tdep->sc_reg_offset = i386bsd_sc_reg_offset;
87   tdep->sc_num_regs = ARRAY_SIZE (i386bsd_sc_reg_offset);
88 }
89 
90 
91 static enum gdb_osabi
i386bsd_aout_osabi_sniffer(bfd * abfd)92 i386bsd_aout_osabi_sniffer (bfd *abfd)
93 {
94   if (strcmp (bfd_get_target (abfd), "a.out-i386-netbsd") == 0)
95     return GDB_OSABI_NETBSD_AOUT;
96 
97   if (strcmp (bfd_get_target (abfd), "a.out-i386-freebsd") == 0)
98     return GDB_OSABI_FREEBSD_AOUT;
99 
100   return GDB_OSABI_UNKNOWN;
101 }
102 
103 static enum gdb_osabi
i386bsd_core_osabi_sniffer(bfd * abfd)104 i386bsd_core_osabi_sniffer (bfd *abfd)
105 {
106   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
107     return GDB_OSABI_NETBSD_AOUT;
108 
109   return GDB_OSABI_UNKNOWN;
110 }
111 
112 
113 /* Provide a prototype to silence -Wmissing-prototypes.  */
114 void _initialize_i386bsd_tdep (void);
115 
116 void
_initialize_i386bsd_tdep(void)117 _initialize_i386bsd_tdep (void)
118 {
119   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_aout_flavour,
120 				  i386bsd_aout_osabi_sniffer);
121 
122   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
123   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_unknown_flavour,
124 				  i386bsd_core_osabi_sniffer);
125 }
126