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   int fp_len = TYPE_LENGTH (gdbarch_register_type (current_gdbarch, regnum));
  49
  50   if (regnum >= M68K_FPC_REGNUM)
  51     return 8 * fp_len + (regnum - M68K_FPC_REGNUM) * 4;
  52
  53   return (regnum - M68K_FP0_REGNUM) * fp_len;
  54 }
  55
  56 /* Supply register REGNUM from the buffer specified by FPREGS and LEN
  57    in the floating-point register set REGSET to register cache
  58    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  59
  60 static void
  61 m68kbsd_supply_fpregset (const struct regset *regset,
  62                          struct regcache *regcache,
  63                          int regnum, const void *fpregs, size_t len)
  64 {
  65   const gdb_byte *regs = fpregs;
  66   int i;
  67
  68   gdb_assert (len >= M68KBSD_SIZEOF_FPREGS);
  69
  70   for (i = M68K_FP0_REGNUM; i <= M68K_PC_REGNUM; i++)
  71     {
  72       if (regnum == i || regnum == -1)
  73         regcache_raw_supply (regcache, i, regs + m68kbsd_fpreg_offset (i));
  74     }
  75 }
  76
  77 /* Supply register REGNUM from the buffer specified by GREGS and LEN
  78    in the general-purpose register set REGSET to register cache
  79    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  80
  81 static void
  82 m68kbsd_supply_gregset (const struct regset *regset,
  83                         struct regcache *regcache,
  84                         int regnum, const void *gregs, size_t len)
  85 {
  86   const gdb_byte *regs = gregs;
  87   int i;
  88
  89   gdb_assert (len >= M68KBSD_SIZEOF_GREGS);
  90
  91   for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)
  92     {
  93       if (regnum == i || regnum == -1)
  94         regcache_raw_supply (regcache, i, regs + i * 4);
  95     }
  96
  97   if (len >= M68KBSD_SIZEOF_GREGS + M68KBSD_SIZEOF_FPREGS)
  98     {
  99       regs += M68KBSD_SIZEOF_GREGS;
 100       len -= M68KBSD_SIZEOF_GREGS;
 101       m68kbsd_supply_fpregset (regset, regcache, regnum, regs, len);
 102     }
 103 }
 104
 105 /* Motorola 68000 register sets.  */
 106
 107 static struct regset m68kbsd_gregset =
 108 {
 109   NULL,
 110   m68kbsd_supply_gregset
 111 };
 112
 113 static struct regset m68kbsd_fpregset =
 114 {
 115   NULL,
 116   m68kbsd_supply_fpregset
 117 };
 118
 119 /* Return the appropriate register set for the core section identified
 120    by SECT_NAME and SECT_SIZE.  */
 121
 122 static const struct regset *
 123 m68kbsd_regset_from_core_section (struct gdbarch *gdbarch,
 124                                   const char *sect_name, size_t sect_size)
 125 {
 126   if (strcmp (sect_name, ".reg") == 0 && sect_size >= M68KBSD_SIZEOF_GREGS)
 127     return &m68kbsd_gregset;
 128
 129   if (strcmp (sect_name, ".reg2") == 0 && sect_size >= M68KBSD_SIZEOF_FPREGS)
 130     return &m68kbsd_fpregset;
 131
 132   return NULL;
 133 }
 134 \f
 135
 136 /* Signal trampolines.  */
 137
 138 static void
 139 m68kobsd_sigtramp_cache_init (const struct tramp_frame *self,
 140                               struct frame_info *next_frame,
 141                               struct trad_frame_cache *this_cache,
 142                               CORE_ADDR func)
 143 {
 144   CORE_ADDR addr, base, pc;
 145   int regnum;
 146
 147   base = frame_unwind_register_unsigned (next_frame, M68K_SP_REGNUM);
 148
 149   /* The 'addql #4,%sp' instruction at offset 8 adjusts the stack
 150      pointer.  Adjust the frame base accordingly.  */
 151   pc = frame_unwind_register_unsigned (next_frame, M68K_PC_REGNUM);
 152   if ((pc - func) > 8)
 153     base -= 4;
 154
 155   /* Get frame pointer, stack pointer, program counter and processor
 156      state from `struct sigcontext'.  */
 157   addr = get_frame_memory_unsigned (next_frame, base + 8, 4);
 158   trad_frame_set_reg_addr (this_cache, M68K_FP_REGNUM, addr + 8);
 159   trad_frame_set_reg_addr (this_cache, M68K_SP_REGNUM, addr + 12);
 160   trad_frame_set_reg_addr (this_cache, M68K_PC_REGNUM, addr + 20);
 161   trad_frame_set_reg_addr (this_cache, M68K_PS_REGNUM, addr + 24);
 162
 163   /* The sc_ap member of `struct sigcontext' points to additional
 164      hardware state.  Here we find the missing registers.  */
 165   addr = get_frame_memory_unsigned (next_frame, addr + 16, 4) + 4;
 166   for (regnum = M68K_D0_REGNUM; regnum < M68K_FP_REGNUM; regnum++, addr += 4)
 167     trad_frame_set_reg_addr (this_cache, regnum, addr);
 168
 169   /* Construct the frame ID using the function start.  */
 170   trad_frame_set_id (this_cache, frame_id_build (base, func));
 171 }
 172
 173 static const struct tramp_frame m68kobsd_sigtramp = {
 174   SIGTRAMP_FRAME,
 175   2,
 176   {
 177     { 0x206f, -1 }, { 0x000c, -1},      /* moveal %sp@(12),%a0 */
 178     { 0x4e90, -1 },                     /* jsr %a0@ */
 179     { 0x588f, -1 },                     /* addql #4,%sp */
 180     { 0x4e41, -1 },                     /* trap #1 */
 181     { 0x2f40, -1 }, { 0x0004, -1 },     /* moveal %d0,%sp@(4) */
 182     { 0x7001, -1 },                     /* moveq #SYS_exit,%d0 */
 183     { 0x4e40, -1 },                     /* trap #0 */
 184     { TRAMP_SENTINEL_INSN, -1 }
 185   },
 186   m68kobsd_sigtramp_cache_init
 187 };
 188 \f
 189
 190 static void
 191 m68kbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 192 {
 193   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 194
 195   tdep->jb_pc = 5;
 196   tdep->jb_elt_size = 4;
 197
 198   set_gdbarch_decr_pc_after_break (gdbarch, 2);
 199
 200   set_gdbarch_regset_from_core_section
 201     (gdbarch, m68kbsd_regset_from_core_section);
 202 }
 203
 204 /* OpenBSD and NetBSD a.out.  */
 205
 206 static void
 207 m68kbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 208 {
 209   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 210
 211   m68kbsd_init_abi (info, gdbarch);
 212
 213   tdep->struct_return = reg_struct_return;
 214
 215   tramp_frame_prepend_unwinder (gdbarch, &m68kobsd_sigtramp);
 216 }
 217
 218 /* NetBSD ELF.  */
 219
 220 static void
 221 m68kbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 222 {
 223   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 224
 225   m68kbsd_init_abi (info, gdbarch);
 226
 227   /* NetBSD ELF uses the SVR4 ABI.  */
 228   m68k_svr4_init_abi (info, gdbarch);
 229   tdep->struct_return = pcc_struct_return;
 230
 231   /* NetBSD ELF uses SVR4-style shared libraries.  */
 232   set_solib_svr4_fetch_link_map_offsets
 233     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 234 }
 235 \f
 236
 237 static enum gdb_osabi
 238 m68kbsd_aout_osabi_sniffer (bfd *abfd)
 239 {
 240   if (strcmp (bfd_get_target (abfd), "a.out-m68k-netbsd") == 0
 241       || strcmp (bfd_get_target (abfd), "a.out-m68k4k-netbsd") == 0)
 242     return GDB_OSABI_NETBSD_AOUT;
 243
 244   return GDB_OSABI_UNKNOWN;
 245 }
 246
 247 static enum gdb_osabi
 248 m68kbsd_core_osabi_sniffer (bfd *abfd)
 249 {
 250   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
 251     return GDB_OSABI_NETBSD_AOUT;
 252
 253   return GDB_OSABI_UNKNOWN;
 254 }
 255 \f
 256
 257 /* Provide a prototype to silence -Wmissing-prototypes.  */
 258 void _initialize_m68kbsd_tdep (void);
 259
 260 void
 261 _initialize_m68kbsd_tdep (void)
 262 {
 263   gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_aout_flavour,
 264                                   m68kbsd_aout_osabi_sniffer);
 265
 266   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
 267   gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_unknown_flavour,
 268                                   m68kbsd_core_osabi_sniffer);
 269
 270   gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_AOUT,
 271                           m68kbsd_aout_init_abi);
 272   gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_ELF,
 273                           m68kbsd_elf_init_abi);
 274 }