gdb/m68k-bsd-tdep.c

   1 /* Target-dependent code for Motorola 68000 BSD's.
   2
   3    Copyright (C) 2004-2020 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 = regcache->arch ();
  62   const gdb_byte *regs = (const gdb_byte *) 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 (i, regs + m68kbsd_fpreg_offset (gdbarch, i));
  71     }
  72 }
  73
  74 /* Supply register REGNUM from the buffer specified by GREGS and LEN
  75    in the general-purpose register set REGSET to register cache
  76    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  77
  78 static void
  79 m68kbsd_supply_gregset (const struct regset *regset,
  80                         struct regcache *regcache,
  81                         int regnum, const void *gregs, size_t len)
  82 {
  83   const gdb_byte *regs = (const gdb_byte *) gregs;
  84   int i;
  85
  86   gdb_assert (len >= M68KBSD_SIZEOF_GREGS);
  87
  88   for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)
  89     {
  90       if (regnum == i || regnum == -1)
  91         regcache->raw_supply (i, regs + i * 4);
  92     }
  93
  94   if (len >= M68KBSD_SIZEOF_GREGS + M68KBSD_SIZEOF_FPREGS)
  95     {
  96       regs += M68KBSD_SIZEOF_GREGS;
  97       len -= M68KBSD_SIZEOF_GREGS;
  98       m68kbsd_supply_fpregset (regset, regcache, regnum, regs, len);
  99     }
 100 }
 101
 102 /* Motorola 68000 register sets.  */
 103
 104 static const struct regset m68kbsd_gregset =
 105 {
 106   NULL,
 107   m68kbsd_supply_gregset,
 108   NULL,
 109   REGSET_VARIABLE_SIZE
 110 };
 111
 112 static const struct regset m68kbsd_fpregset =
 113 {
 114   NULL,
 115   m68kbsd_supply_fpregset
 116 };
 117
 118 /* Iterate over core file register note sections.  */
 119
 120 static void
 121 m68kbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 122                                       iterate_over_regset_sections_cb *cb,
 123                                       void *cb_data,
 124                                       const struct regcache *regcache)
 125 {
 126   cb (".reg", M68KBSD_SIZEOF_GREGS, M68KBSD_SIZEOF_GREGS, &m68kbsd_gregset,
 127       NULL, cb_data);
 128   cb (".reg2", M68KBSD_SIZEOF_FPREGS, M68KBSD_SIZEOF_FPREGS, &m68kbsd_fpregset,
 129       NULL, cb_data);
 130 }
 131 \f
 132
 133 static void
 134 m68kbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 135 {
 136   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 137
 138   tdep->jb_pc = 5;
 139   tdep->jb_elt_size = 4;
 140
 141   set_gdbarch_decr_pc_after_break (gdbarch, 2);
 142
 143   set_gdbarch_iterate_over_regset_sections
 144     (gdbarch, m68kbsd_iterate_over_regset_sections);
 145
 146   /* NetBSD ELF uses the SVR4 ABI.  */
 147   m68k_svr4_init_abi (info, gdbarch);
 148   tdep->struct_return = pcc_struct_return;
 149
 150   /* NetBSD ELF uses SVR4-style shared libraries.  */
 151   set_solib_svr4_fetch_link_map_offsets
 152     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 153 }
 154
 155 void
 156 _initialize_m68kbsd_tdep (void)
 157 {
 158   gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD,
 159                           m68kbsd_init_abi);
 160 }