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 "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 = 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 /* Return the appropriate register set for the core section identified
  68    by SECT_NAME and SECT_SIZE.  */
  69
  70 static const struct regset *
  71 mips64obsd_regset_from_core_section (struct gdbarch *gdbarch,
  72                                      const char *sect_name, size_t sect_size)
  73 {
  74   if (strcmp (sect_name, ".reg") == 0 && sect_size >= MIPS64OBSD_NUM_REGS * 8)
  75     return &mips64obsd_gregset;
  76
  77   return NULL;
  78 }
  79 \f
  80
  81 /* Signal trampolines.  */
  82
  83 static void
  84 mips64obsd_sigframe_init (const struct tramp_frame *self,
  85                           struct frame_info *this_frame,
  86                           struct trad_frame_cache *cache,
  87                           CORE_ADDR func)
  88 {
  89   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  90   CORE_ADDR sp, sigcontext_addr, addr;
  91   int regnum;
  92
  93   /* We find the appropriate instance of `struct sigcontext' at a
  94      fixed offset in the signal frame.  */
  95   sp = get_frame_register_signed (this_frame,
  96                                   MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
  97   sigcontext_addr = sp + 32;
  98
  99   /* PC.  */
 100   regnum = mips_regnum (gdbarch)->pc;
 101   trad_frame_set_reg_addr (cache,
 102                            regnum + gdbarch_num_regs (gdbarch),
 103                             sigcontext_addr + 16);
 104
 105   /* GPRs.  */
 106   for (regnum = MIPS_AT_REGNUM, addr = sigcontext_addr + 32;
 107        regnum <= MIPS_RA_REGNUM; regnum++, addr += 8)
 108     trad_frame_set_reg_addr (cache,
 109                              regnum + gdbarch_num_regs (gdbarch),
 110                              addr);
 111
 112   /* HI and LO.  */
 113   regnum = mips_regnum (gdbarch)->lo;
 114   trad_frame_set_reg_addr (cache,
 115                            regnum + gdbarch_num_regs (gdbarch),
 116                            sigcontext_addr + 280);
 117   regnum = mips_regnum (gdbarch)->hi;
 118   trad_frame_set_reg_addr (cache,
 119                            regnum + gdbarch_num_regs (gdbarch),
 120                            sigcontext_addr + 288);
 121
 122   /* TODO: Handle the floating-point registers.  */
 123
 124   trad_frame_set_id (cache, frame_id_build (sp, func));
 125 }
 126
 127 static const struct tramp_frame mips64obsd_sigframe =
 128 {
 129   SIGTRAMP_FRAME,
 130   MIPS_INSN32_SIZE,
 131   {
 132     { 0x67a40020, -1 },         /* daddiu  a0,sp,32 */
 133     { 0x24020067, -1 },         /* li      v0,103 */
 134     { 0x0000000c, -1 },         /* syscall */
 135     { 0x0000000d, -1 },         /* break */
 136     { TRAMP_SENTINEL_INSN, -1 }
 137   },
 138   mips64obsd_sigframe_init
 139 };
 140
 141 \f
 142 static void
 143 mips64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 144 {
 145   /* OpenBSD/mips64 only supports the n64 ABI, but the braindamaged
 146      way GDB works, forces us to pretend we can handle them all.  */
 147
 148   set_gdbarch_regset_from_core_section
 149     (gdbarch, mips64obsd_regset_from_core_section);
 150
 151   tramp_frame_prepend_unwinder (gdbarch, &mips64obsd_sigframe);
 152
 153   set_gdbarch_long_double_bit (gdbarch, 128);
 154   set_gdbarch_long_double_format (gdbarch, floatformats_mips64_quad);
 155
 156   obsd_init_abi(info, gdbarch);
 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 }