xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/mips64-obsd-tdep.c (revision 8ecbf5f02b752fcb7debe1a8fab1dc82602bc760)
1 /* Target-dependent code for OpenBSD/mips64.
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 "gdbtypes.h"
22 #include "osabi.h"
23 #include "regcache.h"
24 #include "regset.h"
25 #include "trad-frame.h"
26 #include "tramp-frame.h"
27 
28 #include "obsd-tdep.h"
29 #include "mips-tdep.h"
30 #include "solib-svr4.h"
31 
32 /* The MIPS64 Floating-Point Quad-Precision format is similar to
33    big-endian IA-64 Quad-Precision format.  */
34 #define floatformats_mips64_quad floatformats_ia64_quad
35 
36 #define MIPS64OBSD_NUM_REGS 73
37 
38 /* Core file support.  */
39 
40 /* Supply register REGNUM from the buffer specified by GREGS and LEN
41    in the general-purpose register set REGSET to register cache
42    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
43 
44 static void
45 mips64obsd_supply_gregset (const struct regset *regset,
46 			   struct regcache *regcache, int regnum,
47 			   const void *gregs, size_t len)
48 {
49   const char *regs = (const char *) gregs;
50   int i;
51 
52   for (i = 0; i < MIPS64OBSD_NUM_REGS; i++)
53     {
54       if (regnum == i || regnum == -1)
55 	regcache_raw_supply (regcache, i, regs + i * 8);
56     }
57 }
58 
59 /* OpenBSD/mips64 register set.  */
60 
61 static const struct regset mips64obsd_gregset =
62 {
63   NULL,
64   mips64obsd_supply_gregset
65 };
66 
67 /* Iterate over core file register note sections.  */
68 
69 static void
70 mips64obsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
71 					 iterate_over_regset_sections_cb *cb,
72 					 void *cb_data,
73 					 const struct regcache *regcache)
74 {
75   cb (".reg", MIPS64OBSD_NUM_REGS * 8, &mips64obsd_gregset, NULL, cb_data);
76 }
77 
78 
79 /* Signal trampolines.  */
80 
81 static void
82 mips64obsd_sigframe_init (const struct tramp_frame *self,
83 			  struct frame_info *this_frame,
84 			  struct trad_frame_cache *cache,
85 			  CORE_ADDR func)
86 {
87   struct gdbarch *gdbarch = get_frame_arch (this_frame);
88   CORE_ADDR sp, sigcontext_addr, addr;
89   int regnum;
90 
91   /* We find the appropriate instance of `struct sigcontext' at a
92      fixed offset in the signal frame.  */
93   sp = get_frame_register_signed (this_frame,
94 				  MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
95   sigcontext_addr = sp + 32;
96 
97   /* PC.  */
98   regnum = mips_regnum (gdbarch)->pc;
99   trad_frame_set_reg_addr (cache,
100 			   regnum + gdbarch_num_regs (gdbarch),
101 			    sigcontext_addr + 16);
102 
103   /* GPRs.  */
104   for (regnum = MIPS_AT_REGNUM, addr = sigcontext_addr + 32;
105        regnum <= MIPS_RA_REGNUM; regnum++, addr += 8)
106     trad_frame_set_reg_addr (cache,
107 			     regnum + gdbarch_num_regs (gdbarch),
108 			     addr);
109 
110   /* HI and LO.  */
111   regnum = mips_regnum (gdbarch)->lo;
112   trad_frame_set_reg_addr (cache,
113 			   regnum + gdbarch_num_regs (gdbarch),
114 			   sigcontext_addr + 280);
115   regnum = mips_regnum (gdbarch)->hi;
116   trad_frame_set_reg_addr (cache,
117 			   regnum + gdbarch_num_regs (gdbarch),
118 			   sigcontext_addr + 288);
119 
120   /* TODO: Handle the floating-point registers.  */
121 
122   trad_frame_set_id (cache, frame_id_build (sp, func));
123 }
124 
125 static const struct tramp_frame mips64obsd_sigframe =
126 {
127   SIGTRAMP_FRAME,
128   MIPS_INSN32_SIZE,
129   {
130     { 0x67a40020, -1 },		/* daddiu  a0,sp,32 */
131     { 0x24020067, -1 },		/* li      v0,103 */
132     { 0x0000000c, -1 },		/* syscall */
133     { 0x0000000d, -1 },		/* break */
134     { TRAMP_SENTINEL_INSN, -1 }
135   },
136   mips64obsd_sigframe_init
137 };
138 
139 
140 static void
141 mips64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
142 {
143   /* OpenBSD/mips64 only supports the n64 ABI, but the braindamaged
144      way GDB works, forces us to pretend we can handle them all.  */
145 
146   set_gdbarch_iterate_over_regset_sections
147     (gdbarch, mips64obsd_iterate_over_regset_sections);
148 
149   tramp_frame_prepend_unwinder (gdbarch, &mips64obsd_sigframe);
150 
151   set_gdbarch_long_double_bit (gdbarch, 128);
152   set_gdbarch_long_double_format (gdbarch, floatformats_mips64_quad);
153 
154   obsd_init_abi(info, gdbarch);
155 
156   /* OpenBSD/mips64 has SVR4-style shared libraries.  */
157   set_solib_svr4_fetch_link_map_offsets
158     (gdbarch, svr4_lp64_fetch_link_map_offsets);
159 }
160 
161 
162 /* Provide a prototype to silence -Wmissing-prototypes.  */
163 void _initialize_mips64obsd_tdep (void);
164 
165 void
166 _initialize_mips64obsd_tdep (void)
167 {
168   gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_OPENBSD,
169 			  mips64obsd_init_abi);
170 }
171