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 "obsd-tdep.h"
  32 #include "mips-tdep.h"
  33 #include "solib-svr4.h"
  34
  35 /* The MIPS64 Floating-Point Quad-Precision format is similar to
  36    big-endian IA-64 Quad-Precision format.  */
  37 #define floatformats_mips64_quad floatformats_ia64_quad
  38
  39 #define MIPS64OBSD_NUM_REGS 73
  40
  41 /* Core file support.  */
  42
  43 /* Supply register REGNUM from the buffer specified by GREGS and LEN
  44    in the general-purpose register set REGSET to register cache
  45    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  46
  47 static void
  48 mips64obsd_supply_gregset (const struct regset *regset,
  49                            struct regcache *regcache, int regnum,
  50                            const void *gregs, size_t len)
  51 {
  52   const char *regs = gregs;
  53   int i;
  54
  55   for (i = 0; i < MIPS64OBSD_NUM_REGS; i++)
  56     {
  57       if (regnum == i || regnum == -1)
  58         regcache_raw_supply (regcache, i, regs + i * 8);
  59     }
  60 }
  61
  62 /* OpenBSD/mips64 register set.  */
  63
  64 static struct regset mips64obsd_gregset =
  65 {
  66   NULL,
  67   mips64obsd_supply_gregset
  68 };
  69
  70 /* Return the appropriate register set for the core section identified
  71    by SECT_NAME and SECT_SIZE.  */
  72
  73 static const struct regset *
  74 mips64obsd_regset_from_core_section (struct gdbarch *gdbarch,
  75                                      const char *sect_name, size_t sect_size)
  76 {
  77   if (strcmp (sect_name, ".reg") == 0 && sect_size >= MIPS64OBSD_NUM_REGS * 8)
  78     return &mips64obsd_gregset;
  79
  80   return NULL;
  81 }
  82 \f
  83
  84 /* Signal trampolines.  */
  85
  86 static void
  87 mips64obsd_sigframe_init (const struct tramp_frame *self,
  88                           struct frame_info *this_frame,
  89                           struct trad_frame_cache *cache,
  90                           CORE_ADDR func)
  91 {
  92   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  93   CORE_ADDR sp, sigcontext_addr, addr;
  94   int regnum;
  95
  96   /* We find the appropriate instance of `struct sigcontext' at a
  97      fixed offset in the signal frame.  */
  98   sp = get_frame_register_signed (this_frame,
  99                                   MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
 100   sigcontext_addr = sp + 32;
 101
 102   /* PC.  */
 103   regnum = mips_regnum (gdbarch)->pc;
 104   trad_frame_set_reg_addr (cache,
 105                            regnum + gdbarch_num_regs (gdbarch),
 106                             sigcontext_addr + 16);
 107
 108   /* GPRs.  */
 109   for (regnum = MIPS_AT_REGNUM, addr = sigcontext_addr + 32;
 110        regnum <= MIPS_RA_REGNUM; regnum++, addr += 8)
 111     trad_frame_set_reg_addr (cache,
 112                              regnum + gdbarch_num_regs (gdbarch),
 113                              addr);
 114
 115   /* HI and LO.  */
 116   regnum = mips_regnum (gdbarch)->lo;
 117   trad_frame_set_reg_addr (cache,
 118                            regnum + gdbarch_num_regs (gdbarch),
 119                            sigcontext_addr + 280);
 120   regnum = mips_regnum (gdbarch)->hi;
 121   trad_frame_set_reg_addr (cache,
 122                            regnum + gdbarch_num_regs (gdbarch),
 123                            sigcontext_addr + 288);
 124
 125   /* TODO: Handle the floating-point registers.  */
 126
 127   trad_frame_set_id (cache, frame_id_build (sp, func));
 128 }
 129
 130 static const struct tramp_frame mips64obsd_sigframe =
 131 {
 132   SIGTRAMP_FRAME,
 133   MIPS_INSN32_SIZE,
 134   {
 135     { 0x67a40020, -1 },         /* daddiu  a0,sp,32 */
 136     { 0x24020067, -1 },         /* li      v0,103 */
 137     { 0x0000000c, -1 },         /* syscall */
 138     { 0x0000000d, -1 },         /* break */
 139     { TRAMP_SENTINEL_INSN, -1 }
 140   },
 141   mips64obsd_sigframe_init
 142 };
 143
 144 \f
 145 static void
 146 mips64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 147 {
 148   /* OpenBSD/mips64 only supports the n64 ABI, but the braindamaged
 149      way GDB works, forces us to pretend we can handle them all.  */
 150
 151   set_gdbarch_regset_from_core_section
 152     (gdbarch, mips64obsd_regset_from_core_section);
 153
 154   tramp_frame_prepend_unwinder (gdbarch, &mips64obsd_sigframe);
 155
 156   set_gdbarch_long_double_bit (gdbarch, 128);
 157   set_gdbarch_long_double_format (gdbarch, floatformats_mips64_quad);
 158
 159   obsd_init_abi(info, gdbarch);
 160
 161   /* OpenBSD/mips64 has SVR4-style shared libraries.  */
 162   set_solib_svr4_fetch_link_map_offsets
 163     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 164 }
 165
 166 \f
 167 /* Provide a prototype to silence -Wmissing-prototypes.  */
 168 void _initialize_mips64obsd_tdep (void);
 169
 170 void
 171 _initialize_mips64obsd_tdep (void)
 172 {
 173   gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_OPENBSD_ELF,
 174                           mips64obsd_init_abi);
 175 }