gdb/m68kbsd-tdep.c

   1 /* Target-dependent code for Motorola 68000 BSD's.
   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 "arch-utils.h"
  22 #include "frame.h"
  23 #include "osabi.h"
  24 #include "regcache.h"
  25 #include "regset.h"
  26 #include "trad-frame.h"
  27 #include "tramp-frame.h"
  28 #include "gdbtypes.h"
  29
  30 #include "m68k-tdep.h"
  31 #include "solib-svr4.h"
  32
  33 /* Core file support.  */
  34
  35 /* Sizeof `struct reg' in <machine/reg.h>.  */
  36 #define M68KBSD_SIZEOF_GREGS    (18 * 4)
  37
  38 /* Sizeof `struct fpreg' in <machine/reg.h.  */
  39 #define M68KBSD_SIZEOF_FPREGS   (((8 * 3) + 3) * 4)
  40
  41 int
  42 m68kbsd_fpreg_offset (struct gdbarch *gdbarch, int regnum)
  43 {
  44   int fp_len = TYPE_LENGTH (gdbarch_register_type (gdbarch, regnum));
  45
  46   if (regnum >= M68K_FPC_REGNUM)
  47     return 8 * fp_len + (regnum - M68K_FPC_REGNUM) * 4;
  48
  49   return (regnum - M68K_FP0_REGNUM) * fp_len;
  50 }
  51
  52 /* Supply register REGNUM from the buffer specified by FPREGS and LEN
  53    in the floating-point register set REGSET to register cache
  54    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  55
  56 static void
  57 m68kbsd_supply_fpregset (const struct regset *regset,
  58                          struct regcache *regcache,
  59                          int regnum, const void *fpregs, size_t len)
  60 {
  61   struct gdbarch *gdbarch = get_regcache_arch (regcache);
  62   const gdb_byte *regs = fpregs;
  63   int i;
  64
  65   gdb_assert (len >= M68KBSD_SIZEOF_FPREGS);
  66
  67   for (i = M68K_FP0_REGNUM; i <= M68K_PC_REGNUM; i++)
  68     {
  69       if (regnum == i || regnum == -1)
  70         regcache_raw_supply (regcache, i,
  71                              regs + m68kbsd_fpreg_offset (gdbarch, i));
  72     }
  73 }
  74
  75 /* Supply register REGNUM from the buffer specified by GREGS and LEN
  76    in the general-purpose register set REGSET to register cache
  77    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  78
  79 static void
  80 m68kbsd_supply_gregset (const struct regset *regset,
  81                         struct regcache *regcache,
  82                         int regnum, const void *gregs, size_t len)
  83 {
  84   const gdb_byte *regs = gregs;
  85   int i;
  86
  87   gdb_assert (len >= M68KBSD_SIZEOF_GREGS);
  88
  89   for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)
  90     {
  91       if (regnum == i || regnum == -1)
  92         regcache_raw_supply (regcache, i, regs + i * 4);
  93     }
  94
  95   if (len >= M68KBSD_SIZEOF_GREGS + M68KBSD_SIZEOF_FPREGS)
  96     {
  97       regs += M68KBSD_SIZEOF_GREGS;
  98       len -= M68KBSD_SIZEOF_GREGS;
  99       m68kbsd_supply_fpregset (regset, regcache, regnum, regs, len);
 100     }
 101 }
 102
 103 /* Motorola 68000 register sets.  */
 104
 105 static const struct regset m68kbsd_gregset =
 106 {
 107   NULL,
 108   m68kbsd_supply_gregset
 109 };
 110
 111 static const struct regset m68kbsd_fpregset =
 112 {
 113   NULL,
 114   m68kbsd_supply_fpregset
 115 };
 116
 117 /* Iterate over core file register note sections.  */
 118
 119 static void
 120 m68kbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 121                                       iterate_over_regset_sections_cb *cb,
 122                                       void *cb_data,
 123                                       const struct regcache *regcache)
 124 {
 125   cb (".reg", M68KBSD_SIZEOF_GREGS, &m68kbsd_gregset, NULL, cb_data);
 126   cb (".reg2", M68KBSD_SIZEOF_FPREGS, &m68kbsd_fpregset, NULL, cb_data);
 127 }
 128 \f
 129
 130 /* Signal trampolines.  */
 131
 132 static void
 133 m68kobsd_sigtramp_cache_init (const struct tramp_frame *self,
 134                               struct frame_info *this_frame,
 135                               struct trad_frame_cache *this_cache,
 136                               CORE_ADDR func)
 137 {
 138   CORE_ADDR addr, base, pc;
 139   int regnum;
 140
 141   base = get_frame_register_unsigned (this_frame, M68K_SP_REGNUM);
 142
 143   /* The 'addql #4,%sp' instruction at offset 8 adjusts the stack
 144      pointer.  Adjust the frame base accordingly.  */
 145   pc = get_frame_register_unsigned (this_frame, M68K_PC_REGNUM);
 146   if ((pc - func) > 8)
 147     base -= 4;
 148
 149   /* Get frame pointer, stack pointer, program counter and processor
 150      state from `struct sigcontext'.  */
 151   addr = get_frame_memory_unsigned (this_frame, base + 8, 4);
 152   trad_frame_set_reg_addr (this_cache, M68K_FP_REGNUM, addr + 8);
 153   trad_frame_set_reg_addr (this_cache, M68K_SP_REGNUM, addr + 12);
 154   trad_frame_set_reg_addr (this_cache, M68K_PC_REGNUM, addr + 20);
 155   trad_frame_set_reg_addr (this_cache, M68K_PS_REGNUM, addr + 24);
 156
 157   /* The sc_ap member of `struct sigcontext' points to additional
 158      hardware state.  Here we find the missing registers.  */
 159   addr = get_frame_memory_unsigned (this_frame, addr + 16, 4) + 4;
 160   for (regnum = M68K_D0_REGNUM; regnum < M68K_FP_REGNUM; regnum++, addr += 4)
 161     trad_frame_set_reg_addr (this_cache, regnum, addr);
 162
 163   /* Construct the frame ID using the function start.  */
 164   trad_frame_set_id (this_cache, frame_id_build (base, func));
 165 }
 166
 167 static const struct tramp_frame m68kobsd_sigtramp = {
 168   SIGTRAMP_FRAME,
 169   2,
 170   {
 171     { 0x206f, -1 }, { 0x000c, -1},      /* moveal %sp@(12),%a0 */
 172     { 0x4e90, -1 },                     /* jsr %a0@ */
 173     { 0x588f, -1 },                     /* addql #4,%sp */
 174     { 0x4e41, -1 },                     /* trap #1 */
 175     { 0x2f40, -1 }, { 0x0004, -1 },     /* moveal %d0,%sp@(4) */
 176     { 0x7001, -1 },                     /* moveq #SYS_exit,%d0 */
 177     { 0x4e40, -1 },                     /* trap #0 */
 178     { TRAMP_SENTINEL_INSN, -1 }
 179   },
 180   m68kobsd_sigtramp_cache_init
 181 };
 182 \f
 183
 184 static void
 185 m68kbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 186 {
 187   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 188
 189   tdep->jb_pc = 5;
 190   tdep->jb_elt_size = 4;
 191
 192   set_gdbarch_decr_pc_after_break (gdbarch, 2);
 193
 194   set_gdbarch_iterate_over_regset_sections
 195     (gdbarch, m68kbsd_iterate_over_regset_sections);
 196 }
 197
 198 /* OpenBSD and NetBSD a.out.  */
 199
 200 static void
 201 m68kbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 202 {
 203   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 204
 205   m68kbsd_init_abi (info, gdbarch);
 206
 207   tdep->struct_return = reg_struct_return;
 208
 209   tramp_frame_prepend_unwinder (gdbarch, &m68kobsd_sigtramp);
 210 }
 211
 212 /* NetBSD ELF.  */
 213
 214 static void
 215 m68kbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 216 {
 217   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 218
 219   m68kbsd_init_abi (info, gdbarch);
 220
 221   /* NetBSD ELF uses the SVR4 ABI.  */
 222   m68k_svr4_init_abi (info, gdbarch);
 223   tdep->struct_return = pcc_struct_return;
 224
 225   /* NetBSD ELF uses SVR4-style shared libraries.  */
 226   set_solib_svr4_fetch_link_map_offsets
 227     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 228 }
 229 \f
 230
 231 static enum gdb_osabi
 232 m68kbsd_aout_osabi_sniffer (bfd *abfd)
 233 {
 234   if (strcmp (bfd_get_target (abfd), "a.out-m68k-netbsd") == 0
 235       || strcmp (bfd_get_target (abfd), "a.out-m68k4k-netbsd") == 0)
 236     return GDB_OSABI_NETBSD_AOUT;
 237
 238   return GDB_OSABI_UNKNOWN;
 239 }
 240
 241 static enum gdb_osabi
 242 m68kbsd_core_osabi_sniffer (bfd *abfd)
 243 {
 244   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
 245     return GDB_OSABI_NETBSD_AOUT;
 246
 247   return GDB_OSABI_UNKNOWN;
 248 }
 249 \f
 250
 251 /* Provide a prototype to silence -Wmissing-prototypes.  */
 252 void _initialize_m68kbsd_tdep (void);
 253
 254 void
 255 _initialize_m68kbsd_tdep (void)
 256 {
 257   gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_aout_flavour,
 258                                   m68kbsd_aout_osabi_sniffer);
 259
 260   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
 261   gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_unknown_flavour,
 262                                   m68kbsd_core_osabi_sniffer);
 263
 264   gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_AOUT,
 265                           m68kbsd_aout_init_abi);
 266   gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_ELF,
 267                           m68kbsd_elf_init_abi);
 268 }