gdb/m68kbsd-tdep.c

   1 /* Target-dependent code for Motorola 68000 BSD's.
   2
   3    Copyright (C) 2004, 2005, 2007, 2008, 2009, 2010
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "arch-utils.h"
  23 #include "frame.h"
  24 #include "osabi.h"
  25 #include "regcache.h"
  26 #include "regset.h"
  27 #include "trad-frame.h"
  28 #include "tramp-frame.h"
  29 #include "gdbtypes.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 (struct gdbarch *gdbarch, int regnum)
  47 {
  48   int fp_len = TYPE_LENGTH (gdbarch_register_type (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   struct gdbarch *gdbarch = get_regcache_arch (regcache);
  66   const gdb_byte *regs = fpregs;
  67   int i;
  68
  69   gdb_assert (len >= M68KBSD_SIZEOF_FPREGS);
  70
  71   for (i = M68K_FP0_REGNUM; i <= M68K_PC_REGNUM; i++)
  72     {
  73       if (regnum == i || regnum == -1)
  74         regcache_raw_supply (regcache, i,
  75                              regs + m68kbsd_fpreg_offset (gdbarch, i));
  76     }
  77 }
  78
  79 /* Supply register REGNUM from the buffer specified by GREGS and LEN
  80    in the general-purpose register set REGSET to register cache
  81    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  82
  83 static void
  84 m68kbsd_supply_gregset (const struct regset *regset,
  85                         struct regcache *regcache,
  86                         int regnum, const void *gregs, size_t len)
  87 {
  88   const gdb_byte *regs = gregs;
  89   int i;
  90
  91   gdb_assert (len >= M68KBSD_SIZEOF_GREGS);
  92
  93   for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)
  94     {
  95       if (regnum == i || regnum == -1)
  96         regcache_raw_supply (regcache, i, regs + i * 4);
  97     }
  98
  99   if (len >= M68KBSD_SIZEOF_GREGS + M68KBSD_SIZEOF_FPREGS)
 100     {
 101       regs += M68KBSD_SIZEOF_GREGS;
 102       len -= M68KBSD_SIZEOF_GREGS;
 103       m68kbsd_supply_fpregset (regset, regcache, regnum, regs, len);
 104     }
 105 }
 106
 107 /* Motorola 68000 register sets.  */
 108
 109 static struct regset m68kbsd_gregset =
 110 {
 111   NULL,
 112   m68kbsd_supply_gregset
 113 };
 114
 115 static struct regset m68kbsd_fpregset =
 116 {
 117   NULL,
 118   m68kbsd_supply_fpregset
 119 };
 120
 121 /* Return the appropriate register set for the core section identified
 122    by SECT_NAME and SECT_SIZE.  */
 123
 124 static const struct regset *
 125 m68kbsd_regset_from_core_section (struct gdbarch *gdbarch,
 126                                   const char *sect_name, size_t sect_size)
 127 {
 128   if (strcmp (sect_name, ".reg") == 0 && sect_size >= M68KBSD_SIZEOF_GREGS)
 129     return &m68kbsd_gregset;
 130
 131   if (strcmp (sect_name, ".reg2") == 0 && sect_size >= M68KBSD_SIZEOF_FPREGS)
 132     return &m68kbsd_fpregset;
 133
 134   return NULL;
 135 }
 136 \f
 137
 138 /* Signal trampolines.  */
 139
 140 static void
 141 m68kobsd_sigtramp_cache_init (const struct tramp_frame *self,
 142                               struct frame_info *this_frame,
 143                               struct trad_frame_cache *this_cache,
 144                               CORE_ADDR func)
 145 {
 146   CORE_ADDR addr, base, pc;
 147   int regnum;
 148
 149   base = get_frame_register_unsigned (this_frame, M68K_SP_REGNUM);
 150
 151   /* The 'addql #4,%sp' instruction at offset 8 adjusts the stack
 152      pointer.  Adjust the frame base accordingly.  */
 153   pc = get_frame_register_unsigned (this_frame, M68K_PC_REGNUM);
 154   if ((pc - func) > 8)
 155     base -= 4;
 156
 157   /* Get frame pointer, stack pointer, program counter and processor
 158      state from `struct sigcontext'.  */
 159   addr = get_frame_memory_unsigned (this_frame, base + 8, 4);
 160   trad_frame_set_reg_addr (this_cache, M68K_FP_REGNUM, addr + 8);
 161   trad_frame_set_reg_addr (this_cache, M68K_SP_REGNUM, addr + 12);
 162   trad_frame_set_reg_addr (this_cache, M68K_PC_REGNUM, addr + 20);
 163   trad_frame_set_reg_addr (this_cache, M68K_PS_REGNUM, addr + 24);
 164
 165   /* The sc_ap member of `struct sigcontext' points to additional
 166      hardware state.  Here we find the missing registers.  */
 167   addr = get_frame_memory_unsigned (this_frame, addr + 16, 4) + 4;
 168   for (regnum = M68K_D0_REGNUM; regnum < M68K_FP_REGNUM; regnum++, addr += 4)
 169     trad_frame_set_reg_addr (this_cache, regnum, addr);
 170
 171   /* Construct the frame ID using the function start.  */
 172   trad_frame_set_id (this_cache, frame_id_build (base, func));
 173 }
 174
 175 static const struct tramp_frame m68kobsd_sigtramp = {
 176   SIGTRAMP_FRAME,
 177   2,
 178   {
 179     { 0x206f, -1 }, { 0x000c, -1},      /* moveal %sp@(12),%a0 */
 180     { 0x4e90, -1 },                     /* jsr %a0@ */
 181     { 0x588f, -1 },                     /* addql #4,%sp */
 182     { 0x4e41, -1 },                     /* trap #1 */
 183     { 0x2f40, -1 }, { 0x0004, -1 },     /* moveal %d0,%sp@(4) */
 184     { 0x7001, -1 },                     /* moveq #SYS_exit,%d0 */
 185     { 0x4e40, -1 },                     /* trap #0 */
 186     { TRAMP_SENTINEL_INSN, -1 }
 187   },
 188   m68kobsd_sigtramp_cache_init
 189 };
 190 \f
 191
 192 static void
 193 m68kbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 194 {
 195   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 196
 197   tdep->jb_pc = 5;
 198   tdep->jb_elt_size = 4;
 199
 200   set_gdbarch_decr_pc_after_break (gdbarch, 2);
 201
 202   set_gdbarch_regset_from_core_section
 203     (gdbarch, m68kbsd_regset_from_core_section);
 204 }
 205
 206 /* OpenBSD and NetBSD a.out.  */
 207
 208 static void
 209 m68kbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 210 {
 211   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 212
 213   m68kbsd_init_abi (info, gdbarch);
 214
 215   tdep->struct_return = reg_struct_return;
 216
 217   tramp_frame_prepend_unwinder (gdbarch, &m68kobsd_sigtramp);
 218 }
 219
 220 /* NetBSD ELF.  */
 221
 222 static void
 223 m68kbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 224 {
 225   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 226
 227   m68kbsd_init_abi (info, gdbarch);
 228
 229   /* NetBSD ELF uses the SVR4 ABI.  */
 230   m68k_svr4_init_abi (info, gdbarch);
 231   tdep->struct_return = pcc_struct_return;
 232
 233   /* NetBSD ELF uses SVR4-style shared libraries.  */
 234   set_solib_svr4_fetch_link_map_offsets
 235     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 236 }
 237 \f
 238
 239 static enum gdb_osabi
 240 m68kbsd_aout_osabi_sniffer (bfd *abfd)
 241 {
 242   if (strcmp (bfd_get_target (abfd), "a.out-m68k-netbsd") == 0
 243       || strcmp (bfd_get_target (abfd), "a.out-m68k4k-netbsd") == 0)
 244     return GDB_OSABI_NETBSD_AOUT;
 245
 246   return GDB_OSABI_UNKNOWN;
 247 }
 248
 249 static enum gdb_osabi
 250 m68kbsd_core_osabi_sniffer (bfd *abfd)
 251 {
 252   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
 253     return GDB_OSABI_NETBSD_AOUT;
 254
 255   return GDB_OSABI_UNKNOWN;
 256 }
 257 \f
 258
 259 /* Provide a prototype to silence -Wmissing-prototypes.  */
 260 void _initialize_m68kbsd_tdep (void);
 261
 262 void
 263 _initialize_m68kbsd_tdep (void)
 264 {
 265   gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_aout_flavour,
 266                                   m68kbsd_aout_osabi_sniffer);
 267
 268   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
 269   gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_unknown_flavour,
 270                                   m68kbsd_core_osabi_sniffer);
 271
 272   gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_AOUT,
 273                           m68kbsd_aout_init_abi);
 274   gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_ELF,
 275                           m68kbsd_elf_init_abi);
 276 }