gdb/mips64obsd-tdep.c

   1 /* Target-dependent code for OpenBSD/mips64.
   2
   3    Copyright (C) 2004, 2007, 2008, 2009, 2010 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 "osabi.h"
  22 #include "regcache.h"
  23 #include "regset.h"
  24 #include "trad-frame.h"
  25 #include "tramp-frame.h"
  26
  27 #include "gdb_assert.h"
  28 #include "gdb_string.h"
  29
  30 #include "mips-tdep.h"
  31 #include "solib-svr4.h"
  32
  33 #define MIPS64OBSD_NUM_REGS 73
  34
  35 /* Core file support.  */
  36
  37 /* Supply register REGNUM from the buffer specified by GREGS and LEN
  38    in the general-purpose register set REGSET to register cache
  39    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  40
  41 static void
  42 mips64obsd_supply_gregset (const struct regset *regset,
  43                            struct regcache *regcache, int regnum,
  44                            const void *gregs, size_t len)
  45 {
  46   const char *regs = gregs;
  47   int i;
  48
  49   for (i = 0; i < MIPS64OBSD_NUM_REGS; i++)
  50     {
  51       if (regnum == i || regnum == -1)
  52         regcache_raw_supply (regcache, i, regs + i * 8);
  53     }
  54 }
  55
  56 /* OpenBSD/mips64 register set.  */
  57
  58 static struct regset mips64obsd_gregset =
  59 {
  60   NULL,
  61   mips64obsd_supply_gregset
  62 };
  63
  64 /* Return the appropriate register set for the core section identified
  65    by SECT_NAME and SECT_SIZE.  */
  66
  67 static const struct regset *
  68 mips64obsd_regset_from_core_section (struct gdbarch *gdbarch,
  69                                      const char *sect_name, size_t sect_size)
  70 {
  71   if (strcmp (sect_name, ".reg") == 0 && sect_size >= MIPS64OBSD_NUM_REGS * 8)
  72     return &mips64obsd_gregset;
  73
  74   return NULL;
  75 }
  76 \f
  77
  78 /* Signal trampolines.  */
  79
  80 static void
  81 mips64obsd_sigframe_init (const struct tramp_frame *self,
  82                           struct frame_info *this_frame,
  83                           struct trad_frame_cache *cache,
  84                           CORE_ADDR func)
  85 {
  86   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  87   CORE_ADDR sp, sigcontext_addr, addr;
  88   int regnum;
  89
  90   /* We find the appropriate instance of `struct sigcontext' at a
  91      fixed offset in the signal frame.  */
  92   sp = get_frame_register_signed (this_frame,
  93                                   MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
  94   sigcontext_addr = sp + 32;
  95
  96   /* PC.  */
  97   regnum = mips_regnum (gdbarch)->pc;
  98   trad_frame_set_reg_addr (cache,
  99                            regnum + gdbarch_num_regs (gdbarch),
 100                             sigcontext_addr + 16);
 101
 102   /* GPRs.  */
 103   for (regnum = MIPS_AT_REGNUM, addr = sigcontext_addr + 32;
 104        regnum <= MIPS_RA_REGNUM; regnum++, addr += 8)
 105     trad_frame_set_reg_addr (cache,
 106                              regnum + gdbarch_num_regs (gdbarch),
 107                              addr);
 108
 109   /* HI and LO.  */
 110   regnum = mips_regnum (gdbarch)->lo;
 111   trad_frame_set_reg_addr (cache,
 112                            regnum + gdbarch_num_regs (gdbarch),
 113                            sigcontext_addr + 280);
 114   regnum = mips_regnum (gdbarch)->hi;
 115   trad_frame_set_reg_addr (cache,
 116                            regnum + gdbarch_num_regs (gdbarch),
 117                            sigcontext_addr + 288);
 118
 119   /* TODO: Handle the floating-point registers.  */
 120
 121   trad_frame_set_id (cache, frame_id_build (sp, func));
 122 }
 123
 124 static const struct tramp_frame mips64obsd_sigframe =
 125 {
 126   SIGTRAMP_FRAME,
 127   MIPS_INSN32_SIZE,
 128   {
 129     { 0x67a40020, -1 },         /* daddiu  a0,sp,32 */
 130     { 0x24020067, -1 },         /* li      v0,103 */
 131     { 0x0000000c, -1 },         /* syscall */
 132     { 0x0000000d, -1 },         /* break */
 133     { TRAMP_SENTINEL_INSN, -1 }
 134   },
 135   mips64obsd_sigframe_init
 136 };
 137
 138 \f
 139 static void
 140 mips64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 141 {
 142   /* OpenBSD/mips64 only supports the n64 ABI, but the braindamaged
 143      way GDB works, forces us to pretend we can handle them all.  */
 144
 145   set_gdbarch_regset_from_core_section
 146     (gdbarch, mips64obsd_regset_from_core_section);
 147
 148   tramp_frame_prepend_unwinder (gdbarch, &mips64obsd_sigframe);
 149
 150   /* OpenBSD/mips64 has SVR4-style shared libraries.  */
 151   set_solib_svr4_fetch_link_map_offsets
 152     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 153 }
 154
 155 \f
 156 /* Provide a prototype to silence -Wmissing-prototypes.  */
 157 void _initialize_mips64obsd_tdep (void);
 158
 159 void
 160 _initialize_mips64obsd_tdep (void)
 161 {
 162   gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_OPENBSD_ELF,
 163                           mips64obsd_init_abi);
 164 }