gdb/m68kbsd-tdep.c

   1 /* Target-dependent code for Motorola 68000 BSD's.
   2
   3    Copyright (C) 2004, 2005, 2007 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 "arch-utils.h"
  24 #include "frame.h"
  25 #include "osabi.h"
  26 #include "regcache.h"
  27 #include "regset.h"
  28 #include "trad-frame.h"
  29 #include "tramp-frame.h"
  30
  31 #include "gdb_assert.h"
  32 #include "gdb_string.h"
  33
  34 #include "m68k-tdep.h"
  35 #include "solib-svr4.h"
  36
  37 /* Core file support.  */
  38
  39 /* Sizeof `struct reg' in <machine/reg.h>.  */
  40 #define M68KBSD_SIZEOF_GREGS    (18 * 4)
  41
  42 /* Sizeof `struct fpreg' in <machine/reg.h.  */
  43 #define M68KBSD_SIZEOF_FPREGS   (((8 * 3) + 3) * 4)
  44
  45 int
  46 m68kbsd_fpreg_offset (int regnum)
  47 {
  48   if (regnum >= M68K_FPC_REGNUM)
  49     return 8 * 12 + (regnum - M68K_FPC_REGNUM) * 4;
  50
  51   return (regnum - M68K_FP0_REGNUM) * 12;
  52 }
  53
  54 /* Supply register REGNUM from the buffer specified by FPREGS and LEN
  55    in the floating-point register set REGSET to register cache
  56    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  57
  58 static void
  59 m68kbsd_supply_fpregset (const struct regset *regset,
  60                          struct regcache *regcache,
  61                          int regnum, const void *fpregs, size_t len)
  62 {
  63   const gdb_byte *regs = fpregs;
  64   int i;
  65
  66   gdb_assert (len >= M68KBSD_SIZEOF_FPREGS);
  67
  68   for (i = M68K_FP0_REGNUM; i <= M68K_PC_REGNUM; i++)
  69     {
  70       if (regnum == i || regnum == -1)
  71         regcache_raw_supply (regcache, i, regs + m68kbsd_fpreg_offset (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 struct regset m68kbsd_gregset =
 106 {
 107   NULL,
 108   m68kbsd_supply_gregset
 109 };
 110
 111 static struct regset m68kbsd_fpregset =
 112 {
 113   NULL,
 114   m68kbsd_supply_fpregset
 115 };
 116
 117 /* Return the appropriate register set for the core section identified
 118    by SECT_NAME and SECT_SIZE.  */
 119
 120 static const struct regset *
 121 m68kbsd_regset_from_core_section (struct gdbarch *gdbarch,
 122                                   const char *sect_name, size_t sect_size)
 123 {
 124   if (strcmp (sect_name, ".reg") == 0 && sect_size >= M68KBSD_SIZEOF_GREGS)
 125     return &m68kbsd_gregset;
 126
 127   if (strcmp (sect_name, ".reg2") == 0 && sect_size >= M68KBSD_SIZEOF_FPREGS)
 128     return &m68kbsd_fpregset;
 129
 130   return NULL;
 131 }
 132 \f
 133
 134 /* Signal trampolines.  */
 135
 136 static void
 137 m68kobsd_sigtramp_cache_init (const struct tramp_frame *self,
 138                               struct frame_info *next_frame,
 139                               struct trad_frame_cache *this_cache,
 140                               CORE_ADDR func)
 141 {
 142   CORE_ADDR addr, base, pc;
 143   int regnum;
 144
 145   base = frame_unwind_register_unsigned (next_frame, M68K_SP_REGNUM);
 146
 147   /* The 'addql #4,%sp' instruction at offset 8 adjusts the stack
 148      pointer.  Adjust the frame base accordingly.  */
 149   pc = frame_unwind_register_unsigned (next_frame, M68K_PC_REGNUM);
 150   if ((pc - func) > 8)
 151     base -= 4;
 152
 153   /* Get frame pointer, stack pointer, program counter and processor
 154      state from `struct sigcontext'.  */
 155   addr = get_frame_memory_unsigned (next_frame, base + 8, 4);
 156   trad_frame_set_reg_addr (this_cache, M68K_FP_REGNUM, addr + 8);
 157   trad_frame_set_reg_addr (this_cache, M68K_SP_REGNUM, addr + 12);
 158   trad_frame_set_reg_addr (this_cache, M68K_PC_REGNUM, addr + 20);
 159   trad_frame_set_reg_addr (this_cache, M68K_PS_REGNUM, addr + 24);
 160
 161   /* The sc_ap member of `struct sigcontext' points to additional
 162      hardware state.  Here we find the missing registers.  */
 163   addr = get_frame_memory_unsigned (next_frame, addr + 16, 4) + 4;
 164   for (regnum = M68K_D0_REGNUM; regnum < M68K_FP_REGNUM; regnum++, addr += 4)
 165     trad_frame_set_reg_addr (this_cache, regnum, addr);
 166
 167   /* Construct the frame ID using the function start.  */
 168   trad_frame_set_id (this_cache, frame_id_build (base, func));
 169 }
 170
 171 static const struct tramp_frame m68kobsd_sigtramp = {
 172   SIGTRAMP_FRAME,
 173   2,
 174   {
 175     { 0x206f, -1 }, { 0x000c, -1},      /* moveal %sp@(12),%a0 */
 176     { 0x4e90, -1 },                     /* jsr %a0@ */
 177     { 0x588f, -1 },                     /* addql #4,%sp */
 178     { 0x4e41, -1 },                     /* trap #1 */
 179     { 0x2f40, -1 }, { 0x0004, -1 },     /* moveal %d0,%sp@(4) */
 180     { 0x7001, -1 },                     /* moveq #SYS_exit,%d0 */
 181     { 0x4e40, -1 },                     /* trap #0 */
 182     { TRAMP_SENTINEL_INSN, -1 }
 183   },
 184   m68kobsd_sigtramp_cache_init
 185 };
 186 \f
 187
 188 static void
 189 m68kbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 190 {
 191   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 192
 193   tdep->jb_pc = 5;
 194   tdep->jb_elt_size = 4;
 195
 196   set_gdbarch_decr_pc_after_break (gdbarch, 2);
 197
 198   set_gdbarch_regset_from_core_section
 199     (gdbarch, m68kbsd_regset_from_core_section);
 200 }
 201
 202 /* OpenBSD and NetBSD a.out.  */
 203
 204 static void
 205 m68kbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 206 {
 207   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 208
 209   m68kbsd_init_abi (info, gdbarch);
 210
 211   tdep->struct_return = reg_struct_return;
 212
 213   tramp_frame_prepend_unwinder (gdbarch, &m68kobsd_sigtramp);
 214 }
 215
 216 /* NetBSD ELF.  */
 217
 218 static void
 219 m68kbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 220 {
 221   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 222
 223   m68kbsd_init_abi (info, gdbarch);
 224
 225   /* NetBSD ELF uses the SVR4 ABI.  */
 226   m68k_svr4_init_abi (info, gdbarch);
 227   tdep->struct_return = pcc_struct_return;
 228
 229   /* NetBSD ELF uses SVR4-style shared libraries.  */
 230   set_solib_svr4_fetch_link_map_offsets
 231     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 232 }
 233 \f
 234
 235 static enum gdb_osabi
 236 m68kbsd_aout_osabi_sniffer (bfd *abfd)
 237 {
 238   if (strcmp (bfd_get_target (abfd), "a.out-m68k-netbsd") == 0
 239       || strcmp (bfd_get_target (abfd), "a.out-m68k4k-netbsd") == 0)
 240     return GDB_OSABI_NETBSD_AOUT;
 241
 242   return GDB_OSABI_UNKNOWN;
 243 }
 244
 245 static enum gdb_osabi
 246 m68kbsd_core_osabi_sniffer (bfd *abfd)
 247 {
 248   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
 249     return GDB_OSABI_NETBSD_AOUT;
 250
 251   return GDB_OSABI_UNKNOWN;
 252 }
 253 \f
 254
 255 /* Provide a prototype to silence -Wmissing-prototypes.  */
 256 void _initialize_m68kbsd_tdep (void);
 257
 258 void
 259 _initialize_m68kbsd_tdep (void)
 260 {
 261   gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_aout_flavour,
 262                                   m68kbsd_aout_osabi_sniffer);
 263
 264   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
 265   gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_unknown_flavour,
 266                                   m68kbsd_core_osabi_sniffer);
 267
 268   gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_AOUT,
 269                           m68kbsd_aout_init_abi);
 270   gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_ELF,
 271                           m68kbsd_elf_init_abi);
 272 }