xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/m68k-bsd-tdep.c (revision cef8759bd76c1b621f8eab8faa6f208faabc2e15)
1 /* Target-dependent code for Motorola 68000 BSD's.
2 
3    Copyright (C) 2004-2017 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 "osabi.h"
24 #include "regcache.h"
25 #include "regset.h"
26 #include "trad-frame.h"
27 #include "tramp-frame.h"
28 #include "gdbtypes.h"
29 
30 #include "m68k-tdep.h"
31 #include "solib-svr4.h"
32 
33 /* Core file support.  */
34 
35 /* Sizeof `struct reg' in <machine/reg.h>.  */
36 #define M68KBSD_SIZEOF_GREGS	(18 * 4)
37 
38 /* Sizeof `struct fpreg' in <machine/reg.h.  */
39 #define M68KBSD_SIZEOF_FPREGS	(((8 * 3) + 3) * 4)
40 
41 int
42 m68kbsd_fpreg_offset (struct gdbarch *gdbarch, int regnum)
43 {
44   int fp_len = TYPE_LENGTH (gdbarch_register_type (gdbarch, regnum));
45 
46   if (regnum >= M68K_FPC_REGNUM)
47     return 8 * fp_len + (regnum - M68K_FPC_REGNUM) * 4;
48 
49   return (regnum - M68K_FP0_REGNUM) * fp_len;
50 }
51 
52 /* Supply register REGNUM from the buffer specified by FPREGS and LEN
53    in the floating-point register set REGSET to register cache
54    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
55 
56 static void
57 m68kbsd_supply_fpregset (const struct regset *regset,
58 			 struct regcache *regcache,
59 			 int regnum, const void *fpregs, size_t len)
60 {
61   struct gdbarch *gdbarch = get_regcache_arch (regcache);
62   const gdb_byte *regs = (const gdb_byte *) fpregs;
63   int i;
64 
65   gdb_assert (len >= M68KBSD_SIZEOF_FPREGS);
66 
67   for (i = M68K_FP0_REGNUM; i <= M68K_PC_REGNUM; i++)
68     {
69       if (regnum == i || regnum == -1)
70 	regcache_raw_supply (regcache, i,
71 			     regs + m68kbsd_fpreg_offset (gdbarch, i));
72     }
73 }
74 
75 /* Supply register REGNUM from the buffer specified by GREGS and LEN
76    in the general-purpose register set REGSET to register cache
77    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
78 
79 static void
80 m68kbsd_supply_gregset (const struct regset *regset,
81 			struct regcache *regcache,
82 			int regnum, const void *gregs, size_t len)
83 {
84   const gdb_byte *regs = (const gdb_byte *) gregs;
85   int i;
86 
87   gdb_assert (len >= M68KBSD_SIZEOF_GREGS);
88 
89   for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)
90     {
91       if (regnum == i || regnum == -1)
92 	regcache_raw_supply (regcache, i, regs + i * 4);
93     }
94 
95   if (len >= M68KBSD_SIZEOF_GREGS + M68KBSD_SIZEOF_FPREGS)
96     {
97       regs += M68KBSD_SIZEOF_GREGS;
98       len -= M68KBSD_SIZEOF_GREGS;
99       m68kbsd_supply_fpregset (regset, regcache, regnum, regs, len);
100     }
101 }
102 
103 /* Motorola 68000 register sets.  */
104 
105 static const struct regset m68kbsd_gregset =
106 {
107   NULL,
108   m68kbsd_supply_gregset,
109   NULL,
110   REGSET_VARIABLE_SIZE
111 };
112 
113 static const struct regset m68kbsd_fpregset =
114 {
115   NULL,
116   m68kbsd_supply_fpregset
117 };
118 
119 /* Iterate over core file register note sections.  */
120 
121 static void
122 m68kbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
123 				      iterate_over_regset_sections_cb *cb,
124 				      void *cb_data,
125 				      const struct regcache *regcache)
126 {
127   cb (".reg", M68KBSD_SIZEOF_GREGS, &m68kbsd_gregset, NULL, cb_data);
128   cb (".reg2", M68KBSD_SIZEOF_FPREGS, &m68kbsd_fpregset, NULL, cb_data);
129 }
130 
131 
132 static void
133 m68kbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
134 {
135   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
136 
137   tdep->jb_pc = 5;
138   tdep->jb_elt_size = 4;
139 
140   set_gdbarch_decr_pc_after_break (gdbarch, 2);
141 
142   set_gdbarch_iterate_over_regset_sections
143     (gdbarch, m68kbsd_iterate_over_regset_sections);
144 
145   /* NetBSD ELF uses the SVR4 ABI.  */
146   m68k_svr4_init_abi (info, gdbarch);
147   tdep->struct_return = pcc_struct_return;
148 
149   /* NetBSD ELF uses SVR4-style shared libraries.  */
150   set_solib_svr4_fetch_link_map_offsets
151     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
152 }
153 
154 
155 /* Provide a prototype to silence -Wmissing-prototypes.  */
156 void _initialize_m68kbsd_tdep (void);
157 
158 void
159 _initialize_m68kbsd_tdep (void)
160 {
161   gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD,
162 			  m68kbsd_init_abi);
163 }
164