gdb/mips64-obsd-tdep.c

   1 /* Target-dependent code for OpenBSD/mips64.
   2
   3    Copyright (C) 2004-2022 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 \f
  75
  76 /* Signal trampolines.  */
  77
  78 static void
  79 mips64obsd_sigframe_init (const struct tramp_frame *self,
  80                           struct frame_info *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 \f
 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 }