gdb/mips64obsd-tdep.c

   1 /* Target-dependent code for OpenBSD/mips64.
   2
   3    Copyright (C) 2004-2014 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 "gdb_assert.h"
  29 #include <string.h>
  30
  31 #include "mips-tdep.h"
  32 #include "solib-svr4.h"
  33
  34 /* The MIPS64 Floating-Point Quad-Precision format is similar to
  35    big-endian IA-64 Quad-Precision format.  */
  36 #define floatformats_mips64_quad floatformats_ia64_quad
  37
  38 #define MIPS64OBSD_NUM_REGS 73
  39
  40 /* Core file support.  */
  41
  42 /* Supply register REGNUM from the buffer specified by GREGS and LEN
  43    in the general-purpose register set REGSET to register cache
  44    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  45
  46 static void
  47 mips64obsd_supply_gregset (const struct regset *regset,
  48                            struct regcache *regcache, int regnum,
  49                            const void *gregs, size_t len)
  50 {
  51   const char *regs = gregs;
  52   int i;
  53
  54   for (i = 0; i < MIPS64OBSD_NUM_REGS; i++)
  55     {
  56       if (regnum == i || regnum == -1)
  57         regcache_raw_supply (regcache, i, regs + i * 8);
  58     }
  59 }
  60
  61 /* OpenBSD/mips64 register set.  */
  62
  63 static struct regset mips64obsd_gregset =
  64 {
  65   NULL,
  66   mips64obsd_supply_gregset
  67 };
  68
  69 /* Return the appropriate register set for the core section identified
  70    by SECT_NAME and SECT_SIZE.  */
  71
  72 static const struct regset *
  73 mips64obsd_regset_from_core_section (struct gdbarch *gdbarch,
  74                                      const char *sect_name, size_t sect_size)
  75 {
  76   if (strcmp (sect_name, ".reg") == 0 && sect_size >= MIPS64OBSD_NUM_REGS * 8)
  77     return &mips64obsd_gregset;
  78
  79   return NULL;
  80 }
  81 \f
  82
  83 /* Signal trampolines.  */
  84
  85 static void
  86 mips64obsd_sigframe_init (const struct tramp_frame *self,
  87                           struct frame_info *this_frame,
  88                           struct trad_frame_cache *cache,
  89                           CORE_ADDR func)
  90 {
  91   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  92   CORE_ADDR sp, sigcontext_addr, addr;
  93   int regnum;
  94
  95   /* We find the appropriate instance of `struct sigcontext' at a
  96      fixed offset in the signal frame.  */
  97   sp = get_frame_register_signed (this_frame,
  98                                   MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
  99   sigcontext_addr = sp + 32;
 100
 101   /* PC.  */
 102   regnum = mips_regnum (gdbarch)->pc;
 103   trad_frame_set_reg_addr (cache,
 104                            regnum + gdbarch_num_regs (gdbarch),
 105                             sigcontext_addr + 16);
 106
 107   /* GPRs.  */
 108   for (regnum = MIPS_AT_REGNUM, addr = sigcontext_addr + 32;
 109        regnum <= MIPS_RA_REGNUM; regnum++, addr += 8)
 110     trad_frame_set_reg_addr (cache,
 111                              regnum + gdbarch_num_regs (gdbarch),
 112                              addr);
 113
 114   /* HI and LO.  */
 115   regnum = mips_regnum (gdbarch)->lo;
 116   trad_frame_set_reg_addr (cache,
 117                            regnum + gdbarch_num_regs (gdbarch),
 118                            sigcontext_addr + 280);
 119   regnum = mips_regnum (gdbarch)->hi;
 120   trad_frame_set_reg_addr (cache,
 121                            regnum + gdbarch_num_regs (gdbarch),
 122                            sigcontext_addr + 288);
 123
 124   /* TODO: Handle the floating-point registers.  */
 125
 126   trad_frame_set_id (cache, frame_id_build (sp, func));
 127 }
 128
 129 static const struct tramp_frame mips64obsd_sigframe =
 130 {
 131   SIGTRAMP_FRAME,
 132   MIPS_INSN32_SIZE,
 133   {
 134     { 0x67a40020, -1 },         /* daddiu  a0,sp,32 */
 135     { 0x24020067, -1 },         /* li      v0,103 */
 136     { 0x0000000c, -1 },         /* syscall */
 137     { 0x0000000d, -1 },         /* break */
 138     { TRAMP_SENTINEL_INSN, -1 }
 139   },
 140   mips64obsd_sigframe_init
 141 };
 142
 143 \f
 144 static void
 145 mips64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 146 {
 147   /* OpenBSD/mips64 only supports the n64 ABI, but the braindamaged
 148      way GDB works, forces us to pretend we can handle them all.  */
 149
 150   set_gdbarch_regset_from_core_section
 151     (gdbarch, mips64obsd_regset_from_core_section);
 152
 153   tramp_frame_prepend_unwinder (gdbarch, &mips64obsd_sigframe);
 154
 155   set_gdbarch_long_double_bit (gdbarch, 128);
 156   set_gdbarch_long_double_format (gdbarch, floatformats_mips64_quad);
 157
 158   /* OpenBSD/mips64 has SVR4-style shared libraries.  */
 159   set_solib_svr4_fetch_link_map_offsets
 160     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 161 }
 162
 163 \f
 164 /* Provide a prototype to silence -Wmissing-prototypes.  */
 165 void _initialize_mips64obsd_tdep (void);
 166
 167 void
 168 _initialize_mips64obsd_tdep (void)
 169 {
 170   gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_OPENBSD_ELF,
 171                           mips64obsd_init_abi);
 172 }