gdb/mips64obsd-tdep.c

   1 /* Target-dependent code for OpenBSD/mips64.
   2
   3    Copyright (C) 2004 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 2 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, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22 #include "defs.h"
  23 #include "osabi.h"
  24 #include "regcache.h"
  25 #include "regset.h"
  26 #include "trad-frame.h"
  27 #include "tramp-frame.h"
  28
  29 #include "gdb_assert.h"
  30 #include "gdb_string.h"
  31
  32 #include "mips-tdep.h"
  33 #include "solib-svr4.h"
  34
  35 #define MIPS64OBSD_NUM_REGS 73
  36
  37 /* Core file support.  */
  38
  39 /* Supply register REGNUM from the buffer specified by GREGS and LEN
  40    in the general-purpose register set REGSET to register cache
  41    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  42
  43 static void
  44 mips64obsd_supply_gregset (const struct regset *regset,
  45                            struct regcache *regcache, int regnum,
  46                            const void *gregs, size_t len)
  47 {
  48   const char *regs = gregs;
  49   int i;
  50
  51   for (i = 0; i < MIPS64OBSD_NUM_REGS; i++)
  52     {
  53       if (regnum == i || regnum == -1)
  54         regcache_raw_supply (regcache, i, regs + i * 8);
  55     }
  56 }
  57
  58 /* OpenBSD/mips64 register set.  */
  59
  60 static struct regset mips64obsd_gregset =
  61 {
  62   NULL,
  63   mips64obsd_supply_gregset
  64 };
  65
  66 /* Return the appropriate register set for the core section identified
  67    by SECT_NAME and SECT_SIZE.  */
  68
  69 static const struct regset *
  70 mips64obsd_regset_from_core_section (struct gdbarch *gdbarch,
  71                                      const char *sect_name, size_t sect_size)
  72 {
  73   if (strcmp (sect_name, ".reg") == 0 && sect_size >= MIPS64OBSD_NUM_REGS * 8)
  74     return &mips64obsd_gregset;
  75
  76   return NULL;
  77 }
  78 \f
  79
  80 /* Signal trampolines.  */
  81
  82 static void
  83 mips64obsd_sigframe_init (const struct tramp_frame *self,
  84                           struct frame_info *next_frame,
  85                           struct trad_frame_cache *cache,
  86                           CORE_ADDR func)
  87 {
  88   struct gdbarch *gdbarch = get_frame_arch (next_frame);
  89   CORE_ADDR sp, sigcontext_addr, addr;
  90   int regnum;
  91
  92   /* We find the appropriate instance of `struct sigcontext' at a
  93      fixed offset in the signal frame.  */
  94   sp = frame_unwind_register_signed (next_frame, MIPS_SP_REGNUM + NUM_REGS);
  95   sigcontext_addr = sp + 32;
  96
  97   /* PC.  */
  98   regnum = mips_regnum (gdbarch)->pc;
  99   trad_frame_set_reg_addr (cache, regnum + NUM_REGS, sigcontext_addr + 16);
 100
 101   /* GPRs.  */
 102   for (regnum = MIPS_AT_REGNUM, addr = sigcontext_addr + 32;
 103        regnum <= MIPS_RA_REGNUM; regnum++, addr += 8)
 104     trad_frame_set_reg_addr (cache, regnum + NUM_REGS, addr);
 105
 106   /* HI and LO.  */
 107   regnum = mips_regnum (gdbarch)->lo;
 108   trad_frame_set_reg_addr (cache, regnum + NUM_REGS, sigcontext_addr + 280);
 109   regnum = mips_regnum (gdbarch)->hi;
 110   trad_frame_set_reg_addr (cache, regnum + NUM_REGS, sigcontext_addr + 288);
 111
 112   /* TODO: Handle the floating-point registers.  */
 113
 114   trad_frame_set_id (cache, frame_id_build (sp, func));
 115 }
 116
 117 static const struct tramp_frame mips64obsd_sigframe =
 118 {
 119   SIGTRAMP_FRAME,
 120   MIPS_INSN32_SIZE,
 121   {
 122     { 0x67a40020, -1 },         /* daddiu  a0,sp,32 */
 123     { 0x24020067, -1 },         /* li      v0,103 */
 124     { 0x0000000c, -1 },         /* syscall */
 125     { 0x0000000d, -1 },         /* break */
 126     { TRAMP_SENTINEL_INSN, -1 }
 127   },
 128   mips64obsd_sigframe_init
 129 };
 130
 131 \f
 132 static void
 133 mips64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 134 {
 135   /* OpenBSD/mips64 only supports the n64 ABI, but the braindamaged
 136      way GDB works, forces us to pretend we can handle them all.  */
 137
 138   set_gdbarch_regset_from_core_section
 139     (gdbarch, mips64obsd_regset_from_core_section);
 140
 141   tramp_frame_prepend_unwinder (gdbarch, &mips64obsd_sigframe);
 142
 143   /* OpenBSD/mips64 has SVR4-style shared libraries.  */
 144   set_solib_svr4_fetch_link_map_offsets
 145     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 146 }
 147
 148 \f
 149 /* Provide a prototype to silence -Wmissing-prototypes.  */
 150 void _initialize_mips64obsd_tdep (void);
 151
 152 void
 153 _initialize_mips64obsd_tdep (void)
 154 {
 155   gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_OPENBSD_ELF,
 156                           mips64obsd_init_abi);
 157 }