gdb/ppc-netbsd-tdep.c

   1 /* Target-dependent code for NetBSD/powerpc.
   2
   3    Copyright (C) 2002-2022 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 "netbsd-tdep.h"
  32 #include "ppc-tdep.h"
  33 #include "solib-svr4.h"
  34
  35 /* Register offsets from <machine/reg.h>.  */
  36 static ppc_reg_offsets ppcnbsd_reg_offsets;
  37 \f
  38
  39 /* Core file support.  */
  40
  41 /* NetBSD/powerpc register sets.  */
  42
  43 const struct regset ppcnbsd_gregset =
  44 {
  45   &ppcnbsd_reg_offsets,
  46   ppc_supply_gregset
  47 };
  48
  49 const struct regset ppcnbsd_fpregset =
  50 {
  51   &ppcnbsd_reg_offsets,
  52   ppc_supply_fpregset
  53 };
  54
  55 /* Iterate over core file register note sections.  */
  56
  57 static void
  58 ppcnbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
  59                                       iterate_over_regset_sections_cb *cb,
  60                                       void *cb_data,
  61                                       const struct regcache *regcache)
  62 {
  63   cb (".reg", 148, 148, &ppcnbsd_gregset, NULL, cb_data);
  64   cb (".reg2", 264, 264, &ppcnbsd_fpregset, NULL, cb_data);
  65 }
  66 \f
  67
  68 /* NetBSD is confused.  It appears that 1.5 was using the correct SVR4
  69    convention but, 1.6 switched to the below broken convention.  For
  70    the moment use the broken convention.  Ulgh!  */
  71
  72 static enum return_value_convention
  73 ppcnbsd_return_value (struct gdbarch *gdbarch, struct value *function,
  74                       struct type *valtype, struct regcache *regcache,
  75                       gdb_byte *readbuf, const gdb_byte *writebuf)
  76 {
  77 #if 0
  78   if ((valtype->code () == TYPE_CODE_STRUCT
  79        || valtype->code () == TYPE_CODE_UNION)
  80       && !((valtype->length () == 16 || valtype->length () == 8)
  81             && valtype->is_vector ())
  82       && !(valtype->length () == 1
  83            || valtype->length () == 2
  84            || valtype->length () == 4
  85            || valtype->length () == 8))
  86     return RETURN_VALUE_STRUCT_CONVENTION;
  87   else
  88 #endif
  89     return ppc_sysv_abi_broken_return_value (gdbarch, function, valtype,
  90                                              regcache, readbuf, writebuf);
  91 }
  92 \f
  93
  94 /* Signal trampolines.  */
  95
  96 extern const struct tramp_frame ppcnbsd2_sigtramp;
  97
  98 static void
  99 ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
 100                              struct frame_info *this_frame,
 101                              struct trad_frame_cache *this_cache,
 102                              CORE_ADDR func)
 103 {
 104   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 105   ppc_gdbarch_tdep *tdep = gdbarch_tdep<ppc_gdbarch_tdep> (gdbarch);
 106   CORE_ADDR addr, base;
 107   int i;
 108
 109   base = get_frame_register_unsigned (this_frame,
 110                                       gdbarch_sp_regnum (gdbarch));
 111   if (self == &ppcnbsd2_sigtramp)
 112     addr = base + 0x10 + 2 * tdep->wordsize;
 113   else
 114     addr = base + 0x18 + 2 * tdep->wordsize;
 115   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
 116     {
 117       int regnum = i + tdep->ppc_gp0_regnum;
 118       trad_frame_set_reg_addr (this_cache, regnum, addr);
 119     }
 120   trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
 121   addr += tdep->wordsize;
 122   trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
 123   addr += tdep->wordsize;
 124   trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
 125   addr += tdep->wordsize;
 126   trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
 127   addr += tdep->wordsize;
 128   trad_frame_set_reg_addr (this_cache, gdbarch_pc_regnum (gdbarch),
 129                            addr); /* SRR0?  */
 130   addr += tdep->wordsize;
 131
 132   /* Construct the frame ID using the function start.  */
 133   trad_frame_set_id (this_cache, frame_id_build (base, func));
 134 }
 135
 136 static const struct tramp_frame ppcnbsd_sigtramp =
 137 {
 138   SIGTRAMP_FRAME,
 139   4,
 140   {
 141     { 0x3821fff0, ULONGEST_MAX },               /* add r1,r1,-16 */
 142     { 0x4e800021, ULONGEST_MAX },               /* blrl */
 143     { 0x38610018, ULONGEST_MAX },               /* addi r3,r1,24 */
 144     { 0x38000127, ULONGEST_MAX },               /* li r0,295 */
 145     { 0x44000002, ULONGEST_MAX },               /* sc */
 146     { 0x38000001, ULONGEST_MAX },               /* li r0,1 */
 147     { 0x44000002, ULONGEST_MAX },               /* sc */
 148     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 149   },
 150   ppcnbsd_sigtramp_cache_init
 151 };
 152
 153 /* NetBSD 2.0 introduced a slightly different signal trampoline.  */
 154
 155 const struct tramp_frame ppcnbsd2_sigtramp =
 156 {
 157   SIGTRAMP_FRAME,
 158   4,
 159   {
 160     { 0x3821fff0, ULONGEST_MAX },               /* add r1,r1,-16 */
 161     { 0x4e800021, ULONGEST_MAX },               /* blrl */
 162     { 0x38610010, ULONGEST_MAX },               /* addi r3,r1,16 */
 163     { 0x38000127, ULONGEST_MAX },               /* li r0,295 */
 164     { 0x44000002, ULONGEST_MAX },               /* sc */
 165     { 0x38000001, ULONGEST_MAX },               /* li r0,1 */
 166     { 0x44000002, ULONGEST_MAX },               /* sc */
 167     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 168   },
 169   ppcnbsd_sigtramp_cache_init
 170 };
 171 \f
 172
 173 static void
 174 ppcnbsd_init_abi (struct gdbarch_info info,
 175                   struct gdbarch *gdbarch)
 176 {
 177   nbsd_init_abi (info, gdbarch);
 178
 179   /* For NetBSD, this is an on again, off again thing.  Some systems
 180      do use the broken struct convention, and some don't.  */
 181   set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
 182
 183   /* NetBSD uses SVR4-style shared libraries.  */
 184   set_solib_svr4_fetch_link_map_offsets
 185     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 186
 187   set_gdbarch_iterate_over_regset_sections
 188     (gdbarch, ppcnbsd_iterate_over_regset_sections);
 189
 190   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
 191   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd2_sigtramp);
 192 }
 193
 194 void _initialize_ppcnbsd_tdep ();
 195 void
 196 _initialize_ppcnbsd_tdep ()
 197 {
 198   gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD,
 199                           ppcnbsd_init_abi);
 200
 201   /* Avoid initializing the register offsets again if they were
 202      already initialized by ppc-netbsd-nat.c.  */
 203   if (ppcnbsd_reg_offsets.pc_offset == 0)
 204     {
 205       /* General-purpose registers.  */
 206       ppcnbsd_reg_offsets.r0_offset = 0;
 207       ppcnbsd_reg_offsets.gpr_size = 4;
 208       ppcnbsd_reg_offsets.xr_size = 4;
 209       ppcnbsd_reg_offsets.lr_offset = 128;
 210       ppcnbsd_reg_offsets.cr_offset = 132;
 211       ppcnbsd_reg_offsets.xer_offset = 136;
 212       ppcnbsd_reg_offsets.ctr_offset = 140;
 213       ppcnbsd_reg_offsets.pc_offset = 144;
 214       ppcnbsd_reg_offsets.ps_offset = -1;
 215       ppcnbsd_reg_offsets.mq_offset = -1;
 216
 217       /* Floating-point registers.  */
 218       ppcnbsd_reg_offsets.f0_offset = 0;
 219       ppcnbsd_reg_offsets.fpscr_offset = 256;
 220       ppcnbsd_reg_offsets.fpscr_size = 4;
 221
 222     }
 223 }