xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/mips64-obsd-tdep.c (revision 6881a4007f077b54e5f51159c52b9b25f57deb0d)
1 /* Target-dependent code for OpenBSD/mips64.
2 
3    Copyright (C) 2004-2023 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 #define MIPS64OBSD_NUM_REGS 73
33 
34 /* Core file support.  */
35 
36 /* Supply register REGNUM from the buffer specified by GREGS and LEN
37    in the general-purpose register set REGSET to register cache
38    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
39 
40 static void
41 mips64obsd_supply_gregset (const struct regset *regset,
42 			   struct regcache *regcache, int regnum,
43 			   const void *gregs, size_t len)
44 {
45   const char *regs = (const char *) gregs;
46   int i;
47 
48   for (i = 0; i < MIPS64OBSD_NUM_REGS; i++)
49     {
50       if (regnum == i || regnum == -1)
51 	regcache->raw_supply (i, regs + i * 8);
52     }
53 }
54 
55 /* OpenBSD/mips64 register set.  */
56 
57 static const struct regset mips64obsd_gregset =
58 {
59   NULL,
60   mips64obsd_supply_gregset
61 };
62 
63 /* Iterate over core file register note sections.  */
64 
65 static void
66 mips64obsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
67 					 iterate_over_regset_sections_cb *cb,
68 					 void *cb_data,
69 					 const struct regcache *regcache)
70 {
71   cb (".reg", MIPS64OBSD_NUM_REGS * 8, MIPS64OBSD_NUM_REGS * 8,
72       &mips64obsd_gregset, NULL, cb_data);
73 }
74 
75 
76 /* Signal trampolines.  */
77 
78 static void
79 mips64obsd_sigframe_init (const struct tramp_frame *self,
80 			  frame_info_ptr this_frame,
81 			  struct trad_frame_cache *cache,
82 			  CORE_ADDR func)
83 {
84   struct gdbarch *gdbarch = get_frame_arch (this_frame);
85   CORE_ADDR sp, sigcontext_addr, addr;
86   int regnum;
87 
88   /* We find the appropriate instance of `struct sigcontext' at a
89      fixed offset in the signal frame.  */
90   sp = get_frame_register_signed (this_frame,
91 				  MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
92   sigcontext_addr = sp + 32;
93 
94   /* PC.  */
95   regnum = mips_regnum (gdbarch)->pc;
96   trad_frame_set_reg_addr (cache,
97 			   regnum + gdbarch_num_regs (gdbarch),
98 			    sigcontext_addr + 16);
99 
100   /* GPRs.  */
101   for (regnum = MIPS_AT_REGNUM, addr = sigcontext_addr + 32;
102        regnum <= MIPS_RA_REGNUM; regnum++, addr += 8)
103     trad_frame_set_reg_addr (cache,
104 			     regnum + gdbarch_num_regs (gdbarch),
105 			     addr);
106 
107   /* HI and LO.  */
108   regnum = mips_regnum (gdbarch)->lo;
109   trad_frame_set_reg_addr (cache,
110 			   regnum + gdbarch_num_regs (gdbarch),
111 			   sigcontext_addr + 280);
112   regnum = mips_regnum (gdbarch)->hi;
113   trad_frame_set_reg_addr (cache,
114 			   regnum + gdbarch_num_regs (gdbarch),
115 			   sigcontext_addr + 288);
116 
117   /* TODO: Handle the floating-point registers.  */
118 
119   trad_frame_set_id (cache, frame_id_build (sp, func));
120 }
121 
122 static const struct tramp_frame mips64obsd_sigframe =
123 {
124   SIGTRAMP_FRAME,
125   MIPS_INSN32_SIZE,
126   {
127     { 0x67a40020, ULONGEST_MAX },		/* daddiu  a0,sp,32 */
128     { 0x24020067, ULONGEST_MAX },		/* li      v0,103 */
129     { 0x0000000c, ULONGEST_MAX },		/* syscall */
130     { 0x0000000d, ULONGEST_MAX },		/* break */
131     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
132   },
133   mips64obsd_sigframe_init
134 };
135 
136 
137 static void
138 mips64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
139 {
140   /* OpenBSD/mips64 only supports the n64 ABI, but the braindamaged
141      way GDB works, forces us to pretend we can handle them all.  */
142 
143   set_gdbarch_iterate_over_regset_sections
144     (gdbarch, mips64obsd_iterate_over_regset_sections);
145 
146   tramp_frame_prepend_unwinder (gdbarch, &mips64obsd_sigframe);
147 
148   set_gdbarch_long_double_bit (gdbarch, 128);
149   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_quad);
150 
151   obsd_init_abi(info, gdbarch);
152 
153   /* OpenBSD/mips64 has SVR4-style shared libraries.  */
154   set_solib_svr4_fetch_link_map_offsets
155     (gdbarch, svr4_lp64_fetch_link_map_offsets);
156 }
157 
158 void _initialize_mips64obsd_tdep ();
159 void
160 _initialize_mips64obsd_tdep ()
161 {
162   gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_OPENBSD,
163 			  mips64obsd_init_abi);
164 }
165