gdbserver/linux-loongarch-low.cc

   1 /* GNU/Linux/LoongArch specific low level interface, for the remote server
   2    for GDB.
   3    Copyright (C) 2022 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 "server.h"
  21 #include "linux-low.h"
  22 #include "tdesc.h"
  23 #include "elf/common.h"
  24 #include "arch/loongarch.h"
  25
  26 /* Linux target ops definitions for the LoongArch architecture.  */
  27
  28 class loongarch_target : public linux_process_target
  29 {
  30 public:
  31
  32   const regs_info *get_regs_info () override;
  33
  34   int breakpoint_kind_from_pc (CORE_ADDR *pcptr) override;
  35
  36   const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override;
  37
  38 protected:
  39
  40   void low_arch_setup () override;
  41
  42   bool low_cannot_fetch_register (int regno) override;
  43
  44   bool low_cannot_store_register (int regno) override;
  45
  46   bool low_fetch_register (regcache *regcache, int regno) override;
  47
  48   bool low_supports_breakpoints () override;
  49
  50   CORE_ADDR low_get_pc (regcache *regcache) override;
  51
  52   void low_set_pc (regcache *regcache, CORE_ADDR newpc) override;
  53
  54   bool low_breakpoint_at (CORE_ADDR pc) override;
  55 };
  56
  57 /* The singleton target ops object.  */
  58
  59 static loongarch_target the_loongarch_target;
  60
  61 bool
  62 loongarch_target::low_cannot_fetch_register (int regno)
  63 {
  64   gdb_assert_not_reached ("linux target op low_cannot_fetch_register "
  65                           "is not implemented by the target");
  66 }
  67
  68 bool
  69 loongarch_target::low_cannot_store_register (int regno)
  70 {
  71   gdb_assert_not_reached ("linux target op low_cannot_store_register "
  72                           "is not implemented by the target");
  73 }
  74
  75 /* Implementation of linux target ops method "low_arch_setup".  */
  76
  77 void
  78 loongarch_target::low_arch_setup ()
  79 {
  80   static const char *expedite_regs[] = { "r3", "pc", NULL };
  81   loongarch_gdbarch_features features;
  82   target_desc_up tdesc;
  83
  84   features.xlen = sizeof (elf_greg_t);
  85   tdesc = loongarch_create_target_description (features);
  86
  87   if (!tdesc->expedite_regs)
  88     init_target_desc (tdesc.get (), expedite_regs);
  89   current_process ()->tdesc = tdesc.release ();
  90 }
  91
  92 /* Collect GPRs from REGCACHE into BUF.  */
  93
  94 static void
  95 loongarch_fill_gregset (struct regcache *regcache, void *buf)
  96 {
  97   elf_gregset_t *regset = (elf_gregset_t *) buf;
  98   int i;
  99
 100   for (i = 1; i < 32; i++)
 101     collect_register (regcache, i, *regset + i);
 102   collect_register (regcache, LOONGARCH_PC_REGNUM, *regset + LOONGARCH_PC_REGNUM);
 103   collect_register (regcache, LOONGARCH_BADV_REGNUM, *regset + LOONGARCH_BADV_REGNUM);
 104 }
 105
 106 /* Supply GPRs from BUF into REGCACHE.  */
 107
 108 static void
 109 loongarch_store_gregset (struct regcache *regcache, const void *buf)
 110 {
 111   const elf_gregset_t *regset = (const elf_gregset_t *) buf;
 112   int i;
 113
 114   supply_register_zeroed (regcache, 0);
 115   for (i = 1; i < 32; i++)
 116     supply_register (regcache, i, *regset + i);
 117   supply_register (regcache, LOONGARCH_PC_REGNUM, *regset + LOONGARCH_PC_REGNUM);
 118   supply_register (regcache, LOONGARCH_BADV_REGNUM, *regset + LOONGARCH_BADV_REGNUM);
 119 }
 120
 121 /* LoongArch/Linux regsets.  */
 122 static struct regset_info loongarch_regsets[] = {
 123   { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS, sizeof (elf_gregset_t),
 124     GENERAL_REGS, loongarch_fill_gregset, loongarch_store_gregset },
 125   NULL_REGSET
 126 };
 127
 128 /* LoongArch/Linux regset information.  */
 129 static struct regsets_info loongarch_regsets_info =
 130   {
 131     loongarch_regsets, /* regsets */
 132     0, /* num_regsets */
 133     NULL, /* disabled_regsets */
 134   };
 135
 136 /* Definition of linux_target_ops data member "regs_info".  */
 137 static struct regs_info loongarch_regs =
 138   {
 139     NULL, /* regset_bitmap */
 140     NULL, /* usrregs */
 141     &loongarch_regsets_info,
 142   };
 143
 144 /* Implementation of linux target ops method "get_regs_info".  */
 145
 146 const regs_info *
 147 loongarch_target::get_regs_info ()
 148 {
 149   return &loongarch_regs;
 150 }
 151
 152 /* Implementation of linux target ops method "low_fetch_register".  */
 153
 154 bool
 155 loongarch_target::low_fetch_register (regcache *regcache, int regno)
 156 {
 157   if (regno != 0)
 158     return false;
 159   supply_register_zeroed (regcache, 0);
 160   return true;
 161 }
 162
 163 bool
 164 loongarch_target::low_supports_breakpoints ()
 165 {
 166   return true;
 167 }
 168
 169 /* Implementation of linux target ops method "low_get_pc".  */
 170
 171 CORE_ADDR
 172 loongarch_target::low_get_pc (regcache *regcache)
 173 {
 174   if (register_size (regcache->tdesc, 0) == 8)
 175     return linux_get_pc_64bit (regcache);
 176   else
 177     return linux_get_pc_32bit (regcache);
 178 }
 179
 180 /* Implementation of linux target ops method "low_set_pc".  */
 181
 182 void
 183 loongarch_target::low_set_pc (regcache *regcache, CORE_ADDR newpc)
 184 {
 185   if (register_size (regcache->tdesc, 0) == 8)
 186     linux_set_pc_64bit (regcache, newpc);
 187   else
 188     linux_set_pc_32bit (regcache, newpc);
 189 }
 190
 191 #define loongarch_breakpoint_len 4
 192
 193 /* LoongArch BRK software debug mode instruction.
 194    This instruction needs to match gdb/loongarch-tdep.c
 195    (loongarch_default_breakpoint).  */
 196 static const gdb_byte loongarch_breakpoint[] = {0x05, 0x00, 0x2a, 0x00};
 197
 198 /* Implementation of target ops method "breakpoint_kind_from_pc".  */
 199
 200 int
 201 loongarch_target::breakpoint_kind_from_pc (CORE_ADDR *pcptr)
 202 {
 203   return loongarch_breakpoint_len;
 204 }
 205
 206 /* Implementation of target ops method "sw_breakpoint_from_kind".  */
 207
 208 const gdb_byte *
 209 loongarch_target::sw_breakpoint_from_kind (int kind, int *size)
 210 {
 211   *size = loongarch_breakpoint_len;
 212   return (const gdb_byte *) &loongarch_breakpoint;
 213 }
 214
 215 /* Implementation of linux target ops method "low_breakpoint_at".  */
 216
 217 bool
 218 loongarch_target::low_breakpoint_at (CORE_ADDR pc)
 219 {
 220   gdb_byte insn[loongarch_breakpoint_len];
 221
 222   read_memory (pc, (unsigned char *) &insn, loongarch_breakpoint_len);
 223   if (memcmp (insn, loongarch_breakpoint, loongarch_breakpoint_len) == 0)
 224     return true;
 225
 226   return false;
 227 }
 228
 229 /* The linux target ops object.  */
 230
 231 linux_process_target *the_linux_target = &the_loongarch_target;
 232
 233 /* Initialize the LoongArch/Linux target.  */
 234
 235 void
 236 initialize_low_arch ()
 237 {
 238   initialize_regsets_info (&loongarch_regsets_info);
 239 }