gdb/ppc-nbsd-tdep.c

   1 /* Target-dependent code for NetBSD/powerpc.
   2
   3    Copyright (C) 2002-2020 Free Software Foundation, Inc.
   4
   5    Contributed by Wasabi Systems, Inc.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23 #include "gdbtypes.h"
  24 #include "osabi.h"
  25 #include "regcache.h"
  26 #include "regset.h"
  27 #include "trad-frame.h"
  28 #include "tramp-frame.h"
  29
  30 #include "ppc-tdep.h"
  31 #include "ppc-nbsd-tdep.h"
  32 #include "solib-svr4.h"
  33
  34 /* Register offsets from <machine/reg.h>.  */
  35 struct ppc_reg_offsets ppcnbsd_reg_offsets;
  36 \f
  37
  38 /* Core file support.  */
  39
  40 /* NetBSD/powerpc register sets.  */
  41
  42 const struct regset ppcnbsd_gregset =
  43 {
  44   &ppcnbsd_reg_offsets,
  45   ppc_supply_gregset
  46 };
  47
  48 const struct regset ppcnbsd_fpregset =
  49 {
  50   &ppcnbsd_reg_offsets,
  51   ppc_supply_fpregset
  52 };
  53
  54 /* Iterate over core file register note sections.  */
  55
  56 static void
  57 ppcnbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
  58                                       iterate_over_regset_sections_cb *cb,
  59                                       void *cb_data,
  60                                       const struct regcache *regcache)
  61 {
  62   cb (".reg", 148, 148, &ppcnbsd_gregset, NULL, cb_data);
  63   cb (".reg2", 264, 264, &ppcnbsd_fpregset, NULL, cb_data);
  64 }
  65 \f
  66
  67 /* NetBSD is confused.  It appears that 1.5 was using the correct SVR4
  68    convention but, 1.6 switched to the below broken convention.  For
  69    the moment use the broken convention.  Ulgh!  */
  70
  71 static enum return_value_convention
  72 ppcnbsd_return_value (struct gdbarch *gdbarch, struct value *function,
  73                       struct type *valtype, struct regcache *regcache,
  74                       gdb_byte *readbuf, const gdb_byte *writebuf)
  75 {
  76 #if 0
  77   if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
  78        || TYPE_CODE (valtype) == TYPE_CODE_UNION)
  79       && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
  80             && TYPE_VECTOR (valtype))
  81       && !(TYPE_LENGTH (valtype) == 1
  82            || TYPE_LENGTH (valtype) == 2
  83            || TYPE_LENGTH (valtype) == 4
  84            || TYPE_LENGTH (valtype) == 8))
  85     return RETURN_VALUE_STRUCT_CONVENTION;
  86   else
  87 #endif
  88     return ppc_sysv_abi_broken_return_value (gdbarch, function, valtype,
  89                                              regcache, readbuf, writebuf);
  90 }
  91 \f
  92
  93 /* Signal trampolines.  */
  94
  95 extern const struct tramp_frame ppcnbsd2_sigtramp;
  96
  97 static void
  98 ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
  99                              struct frame_info *this_frame,
 100                              struct trad_frame_cache *this_cache,
 101                              CORE_ADDR func)
 102 {
 103   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 104   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 105   CORE_ADDR addr, base;
 106   int i;
 107
 108   base = get_frame_register_unsigned (this_frame,
 109                                       gdbarch_sp_regnum (gdbarch));
 110   if (self == &ppcnbsd2_sigtramp)
 111     addr = base + 0x10 + 2 * tdep->wordsize;
 112   else
 113     addr = base + 0x18 + 2 * tdep->wordsize;
 114   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
 115     {
 116       int regnum = i + tdep->ppc_gp0_regnum;
 117       trad_frame_set_reg_addr (this_cache, regnum, addr);
 118     }
 119   trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
 120   addr += tdep->wordsize;
 121   trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
 122   addr += tdep->wordsize;
 123   trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
 124   addr += tdep->wordsize;
 125   trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
 126   addr += tdep->wordsize;
 127   trad_frame_set_reg_addr (this_cache, gdbarch_pc_regnum (gdbarch),
 128                            addr); /* SRR0?  */
 129   addr += tdep->wordsize;
 130
 131   /* Construct the frame ID using the function start.  */
 132   trad_frame_set_id (this_cache, frame_id_build (base, func));
 133 }
 134
 135 static const struct tramp_frame ppcnbsd_sigtramp =
 136 {
 137   SIGTRAMP_FRAME,
 138   4,
 139   {
 140     { 0x3821fff0, ULONGEST_MAX },               /* add r1,r1,-16 */
 141     { 0x4e800021, ULONGEST_MAX },               /* blrl */
 142     { 0x38610018, ULONGEST_MAX },               /* addi r3,r1,24 */
 143     { 0x38000127, ULONGEST_MAX },               /* li r0,295 */
 144     { 0x44000002, ULONGEST_MAX },               /* sc */
 145     { 0x38000001, ULONGEST_MAX },               /* li r0,1 */
 146     { 0x44000002, ULONGEST_MAX },               /* sc */
 147     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 148   },
 149   ppcnbsd_sigtramp_cache_init
 150 };
 151
 152 /* NetBSD 2.0 introduced a slightly different signal trampoline.  */
 153
 154 const struct tramp_frame ppcnbsd2_sigtramp =
 155 {
 156   SIGTRAMP_FRAME,
 157   4,
 158   {
 159     { 0x3821fff0, ULONGEST_MAX },               /* add r1,r1,-16 */
 160     { 0x4e800021, ULONGEST_MAX },               /* blrl */
 161     { 0x38610010, ULONGEST_MAX },               /* addi r3,r1,16 */
 162     { 0x38000127, ULONGEST_MAX },               /* li r0,295 */
 163     { 0x44000002, ULONGEST_MAX },               /* sc */
 164     { 0x38000001, ULONGEST_MAX },               /* li r0,1 */
 165     { 0x44000002, ULONGEST_MAX },               /* sc */
 166     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 167   },
 168   ppcnbsd_sigtramp_cache_init
 169 };
 170 \f
 171
 172 static void
 173 ppcnbsd_init_abi (struct gdbarch_info info,
 174                   struct gdbarch *gdbarch)
 175 {
 176   /* For NetBSD, this is an on again, off again thing.  Some systems
 177      do use the broken struct convention, and some don't.  */
 178   set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
 179
 180   /* NetBSD uses SVR4-style shared libraries.  */
 181   set_solib_svr4_fetch_link_map_offsets
 182     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 183
 184   set_gdbarch_iterate_over_regset_sections
 185     (gdbarch, ppcnbsd_iterate_over_regset_sections);
 186
 187   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
 188   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd2_sigtramp);
 189 }
 190
 191 void
 192 _initialize_ppcnbsd_tdep (void)
 193 {
 194   gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD,
 195                           ppcnbsd_init_abi);
 196
 197   /* Avoid initializing the register offsets again if they were
 198      already initialized by ppcnbsd-nat.c.  */
 199   if (ppcnbsd_reg_offsets.pc_offset == 0)
 200     {
 201       /* General-purpose registers.  */
 202       ppcnbsd_reg_offsets.r0_offset = 0;
 203       ppcnbsd_reg_offsets.gpr_size = 4;
 204       ppcnbsd_reg_offsets.xr_size = 4;
 205       ppcnbsd_reg_offsets.lr_offset = 128;
 206       ppcnbsd_reg_offsets.cr_offset = 132;
 207       ppcnbsd_reg_offsets.xer_offset = 136;
 208       ppcnbsd_reg_offsets.ctr_offset = 140;
 209       ppcnbsd_reg_offsets.pc_offset = 144;
 210       ppcnbsd_reg_offsets.ps_offset = -1;
 211       ppcnbsd_reg_offsets.mq_offset = -1;
 212
 213       /* Floating-point registers.  */
 214       ppcnbsd_reg_offsets.f0_offset = 0;
 215       ppcnbsd_reg_offsets.fpscr_offset = 256;
 216       ppcnbsd_reg_offsets.fpscr_size = 4;
 217
 218     }
 219 }