gdb/m68kbsd-tdep.c - gdb

Global variables defined

Functions defined

Macros defined

Source code

  1. /* Target-dependent code for Motorola 68000 BSD's.

  3.    Copyright (C) 2004-2015 Free Software Foundation, Inc.

  5.    This file is part of GDB.

  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.

  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.

  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/>.  */

  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"

  30. #include "m68k-tdep.h"
  31. #include "solib-svr4.h"

  33. /* Core file support.  */

  35. /* Sizeof `struct reg' in <machine/reg.h>.  */
  36. ‌#define M68KBSD_SIZEOF_GREGS        (18 * 4)

  38. /* Sizeof `struct fpreg' in <machine/reg.h.  */
  39. ‌#define M68KBSD_SIZEOF_FPREGS        (((8 * 3) + 3) * 4)

  41. int
  42. ‌m68kbsd_fpreg_offset (struct gdbarch *gdbarch, int regnum)
  43. {
  44.   int fp_len = TYPE_LENGTH (gdbarch_register_type (gdbarch, regnum));

  46.   if (regnum >= M68K_FPC_REGNUM)
  47.     return 8 * fp_len + (regnum - M68K_FPC_REGNUM) * 4;

  49.   return (regnum - M68K_FP0_REGNUM) * fp_len;
  50. }

  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.  */

  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;

  65.   gdb_assert (len >= M68KBSD_SIZEOF_FPREGS);

  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. }

  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.  */

  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;

  87.   gdb_assert (len >= M68KBSD_SIZEOF_GREGS);

  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.     }

  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. }

  103. /* Motorola 68000 register sets.  */

  105. ‌static const struct regset m68kbsd_gregset =
  106. {
  107.   NULL,
  108.   m68kbsd_supply_gregset
  109. };

  111. ‌static const struct regset m68kbsd_fpregset =
  112. {
  113.   NULL,
  114.   m68kbsd_supply_fpregset
  115. };

  117. /* Iterate over core file register note sections.  */

  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. }


  130. /* Signal trampolines.  */

  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;

  141.   base = get_frame_register_unsigned (this_frame, M68K_SP_REGNUM);

  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;

  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);

  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);

  163.   /* Construct the frame ID using the function start.  */
  164.   trad_frame_set_id (this_cache, frame_id_build (base, func));
  165. }

  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. };


  184. static void
  185. ‌m68kbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
  186. {
  187.   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  189.   tdep->jb_pc = 5;
  190.   tdep->jb_elt_size = 4;

  192.   set_gdbarch_decr_pc_after_break (gdbarch, 2);

  194.   set_gdbarch_iterate_over_regset_sections
  195.     (gdbarch, m68kbsd_iterate_over_regset_sections);
  196. }

  198. /* OpenBSD and NetBSD a.out.  */

  200. static void
  201. ‌m68kbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
  202. {
  203.   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  205.   m68kbsd_init_abi (info, gdbarch);

  207.   tdep->struct_return = reg_struct_return;

  209.   tramp_frame_prepend_unwinder (gdbarch, &m68kobsd_sigtramp);
  210. }

  212. /* NetBSD ELF.  */

  214. static void
  215. ‌m68kbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
  216. {
  217.   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  219.   m68kbsd_init_abi (info, gdbarch);

  221.   /* NetBSD ELF uses the SVR4 ABI.  */
  222.   m68k_svr4_init_abi (info, gdbarch);
  223.   tdep->struct_return = pcc_struct_return;

  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. }


  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;

  238.   return GDB_OSABI_UNKNOWN;
  239. }

  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;

  247.   return GDB_OSABI_UNKNOWN;
  248. }


  251. /* Provide a prototype to silence -Wmissing-prototypes.  */
  252. void _initialize_m68kbsd_tdep (void);

  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);

  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);

  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. }