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_ORIG_A0_REGNUM, *regset + LOONGARCH_ORIG_A0_REGNUM);
 103   collect_register (regcache, LOONGARCH_PC_REGNUM, *regset + LOONGARCH_PC_REGNUM);
 104   collect_register (regcache, LOONGARCH_BADV_REGNUM, *regset + LOONGARCH_BADV_REGNUM);
 105 }
 106
 107 /* Supply GPRs from BUF into REGCACHE.  */
 108
 109 static void
 110 loongarch_store_gregset (struct regcache *regcache, const void *buf)
 111 {
 112   const elf_gregset_t *regset = (const elf_gregset_t *) buf;
 113   int i;
 114
 115   supply_register_zeroed (regcache, 0);
 116   for (i = 1; i < 32; i++)
 117     supply_register (regcache, i, *regset + i);
 118   supply_register (regcache, LOONGARCH_ORIG_A0_REGNUM, *regset + LOONGARCH_ORIG_A0_REGNUM);
 119   supply_register (regcache, LOONGARCH_PC_REGNUM, *regset + LOONGARCH_PC_REGNUM);
 120   supply_register (regcache, LOONGARCH_BADV_REGNUM, *regset + LOONGARCH_BADV_REGNUM);
 121 }
 122
 123 /* Collect FPRs from REGCACHE into BUF.  */
 124
 125 static void
 126 loongarch_fill_fpregset (struct regcache *regcache, void *buf)
 127 {
 128   gdb_byte *regbuf = nullptr;
 129   int fprsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FP_REGNUM);
 130   int fccsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FCC_REGNUM);
 131
 132   for (int i = 0; i < LOONGARCH_LINUX_NUM_FPREGSET; i++)
 133     {
 134       regbuf = (gdb_byte *)buf + fprsize * i;
 135       collect_register (regcache, LOONGARCH_FIRST_FP_REGNUM + i, regbuf);
 136     }
 137
 138   for (int i = 0; i < LOONGARCH_LINUX_NUM_FCC; i++)
 139     {
 140       regbuf = (gdb_byte *)buf + fprsize * LOONGARCH_LINUX_NUM_FPREGSET +
 141         fccsize * i;
 142       collect_register (regcache, LOONGARCH_FIRST_FCC_REGNUM + i, regbuf);
 143     }
 144
 145   regbuf = (gdb_byte *)buf + fprsize * LOONGARCH_LINUX_NUM_FPREGSET +
 146     fccsize * LOONGARCH_LINUX_NUM_FCC;
 147   collect_register (regcache, LOONGARCH_FCSR_REGNUM, regbuf);
 148 }
 149
 150 /* Supply FPRs from BUF into REGCACHE.  */
 151
 152 static void
 153 loongarch_store_fpregset (struct regcache *regcache, const void *buf)
 154 {
 155   const gdb_byte *regbuf = nullptr;
 156   int fprsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FP_REGNUM);
 157   int fccsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FCC_REGNUM);
 158
 159   for (int i = 0; i < LOONGARCH_LINUX_NUM_FPREGSET; i++)
 160     {
 161       regbuf = (const gdb_byte *)buf + fprsize * i;
 162       supply_register (regcache, LOONGARCH_FIRST_FP_REGNUM + i, regbuf);
 163     }
 164
 165   for (int i = 0; i < LOONGARCH_LINUX_NUM_FCC; i++)
 166     {
 167       regbuf = (const gdb_byte *)buf + fprsize * LOONGARCH_LINUX_NUM_FPREGSET +
 168         fccsize * i;
 169       supply_register (regcache, LOONGARCH_FIRST_FCC_REGNUM + i, regbuf);
 170     }
 171
 172   regbuf = (const gdb_byte *)buf + fprsize * LOONGARCH_LINUX_NUM_FPREGSET +
 173     fccsize * LOONGARCH_LINUX_NUM_FCC;
 174   supply_register (regcache, LOONGARCH_FCSR_REGNUM, regbuf);
 175 }
 176
 177 /* LoongArch/Linux regsets.  */
 178 static struct regset_info loongarch_regsets[] = {
 179   { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS, sizeof (elf_gregset_t),
 180     GENERAL_REGS, loongarch_fill_gregset, loongarch_store_gregset },
 181   { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_FPREGSET, sizeof (elf_fpregset_t),
 182     FP_REGS, loongarch_fill_fpregset, loongarch_store_fpregset },
 183   NULL_REGSET
 184 };
 185
 186 /* LoongArch/Linux regset information.  */
 187 static struct regsets_info loongarch_regsets_info =
 188   {
 189     loongarch_regsets, /* regsets */
 190     0, /* num_regsets */
 191     NULL, /* disabled_regsets */
 192   };
 193
 194 /* Definition of linux_target_ops data member "regs_info".  */
 195 static struct regs_info loongarch_regs =
 196   {
 197     NULL, /* regset_bitmap */
 198     NULL, /* usrregs */
 199     &loongarch_regsets_info,
 200   };
 201
 202 /* Implementation of linux target ops method "get_regs_info".  */
 203
 204 const regs_info *
 205 loongarch_target::get_regs_info ()
 206 {
 207   return &loongarch_regs;
 208 }
 209
 210 /* Implementation of linux target ops method "low_fetch_register".  */
 211
 212 bool
 213 loongarch_target::low_fetch_register (regcache *regcache, int regno)
 214 {
 215   if (regno != 0)
 216     return false;
 217   supply_register_zeroed (regcache, 0);
 218   return true;
 219 }
 220
 221 bool
 222 loongarch_target::low_supports_breakpoints ()
 223 {
 224   return true;
 225 }
 226
 227 /* Implementation of linux target ops method "low_get_pc".  */
 228
 229 CORE_ADDR
 230 loongarch_target::low_get_pc (regcache *regcache)
 231 {
 232   if (register_size (regcache->tdesc, 0) == 8)
 233     return linux_get_pc_64bit (regcache);
 234   else
 235     return linux_get_pc_32bit (regcache);
 236 }
 237
 238 /* Implementation of linux target ops method "low_set_pc".  */
 239
 240 void
 241 loongarch_target::low_set_pc (regcache *regcache, CORE_ADDR newpc)
 242 {
 243   if (register_size (regcache->tdesc, 0) == 8)
 244     linux_set_pc_64bit (regcache, newpc);
 245   else
 246     linux_set_pc_32bit (regcache, newpc);
 247 }
 248
 249 #define loongarch_breakpoint_len 4
 250
 251 /* LoongArch BRK software debug mode instruction.
 252    This instruction needs to match gdb/loongarch-tdep.c
 253    (loongarch_default_breakpoint).  */
 254 static const gdb_byte loongarch_breakpoint[] = {0x05, 0x00, 0x2a, 0x00};
 255
 256 /* Implementation of target ops method "breakpoint_kind_from_pc".  */
 257
 258 int
 259 loongarch_target::breakpoint_kind_from_pc (CORE_ADDR *pcptr)
 260 {
 261   return loongarch_breakpoint_len;
 262 }
 263
 264 /* Implementation of target ops method "sw_breakpoint_from_kind".  */
 265
 266 const gdb_byte *
 267 loongarch_target::sw_breakpoint_from_kind (int kind, int *size)
 268 {
 269   *size = loongarch_breakpoint_len;
 270   return (const gdb_byte *) &loongarch_breakpoint;
 271 }
 272
 273 /* Implementation of linux target ops method "low_breakpoint_at".  */
 274
 275 bool
 276 loongarch_target::low_breakpoint_at (CORE_ADDR pc)
 277 {
 278   gdb_byte insn[loongarch_breakpoint_len];
 279
 280   read_memory (pc, (unsigned char *) &insn, loongarch_breakpoint_len);
 281   if (memcmp (insn, loongarch_breakpoint, loongarch_breakpoint_len) == 0)
 282     return true;
 283
 284   return false;
 285 }
 286
 287 /* The linux target ops object.  */
 288
 289 linux_process_target *the_linux_target = &the_loongarch_target;
 290
 291 /* Initialize the LoongArch/Linux target.  */
 292
 293 void
 294 initialize_low_arch ()
 295 {
 296   initialize_regsets_info (&loongarch_regsets_info);
 297 }