gdb/m32r-linux-nat.c

   1 /* Native-dependent code for GNU/Linux m32r.
   2
   3    Copyright (C) 2004-2024 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 "inferior.h"
  21 #include "gdbcore.h"
  22 #include "regcache.h"
  23 #include "linux-nat.h"
  24 #include "target.h"
  25 #include "nat/gdb_ptrace.h"
  26 #include <sys/user.h>
  27 #include <sys/procfs.h>
  28 #include "inf-ptrace.h"
  29
  30 /* Prototypes for supply_gregset etc.  */
  31 #include "gregset.h"
  32
  33 #include "m32r-tdep.h"
  34 \f
  35
  36 class m32r_linux_nat_target final : public linux_nat_target
  37 {
  38 public:
  39   /* Add our register access methods.  */
  40   void fetch_registers (struct regcache *, int) override;
  41   void store_registers (struct regcache *, int) override;
  42 };
  43
  44 static m32r_linux_nat_target the_m32r_linux_nat_target;
  45
  46 /* Since EVB register is not available for native debug, we reduce
  47    the number of registers.  */
  48 #define M32R_LINUX_NUM_REGS (M32R_NUM_REGS - 1)
  49
  50 /* Mapping between the general-purpose registers in `struct user'
  51    format and GDB's register array layout.  */
  52 static int regmap[] = {
  53   4, 5, 6, 7, 0, 1, 2, 8,
  54   9, 10, 11, 12, 13, 24, 25, 23,
  55   19, 19, 26, 23, 22, 20, 16, 15
  56 };
  57
  58 #define PSW_REGMAP 19
  59 #define BBPSW_REGMAP 21
  60 #define SPU_REGMAP 23
  61 #define SPI_REGMAP 26
  62
  63 /* Doee (??) apply to the corresponding SET requests as well.  */
  64 #define GETREGS_SUPPLIES(regno) (0 <= (regno) \
  65                                  && (regno) <= M32R_LINUX_NUM_REGS)
  66 \f
  67
  68
  69 /* Transferring the general-purpose registers between GDB, inferiors
  70    and core files.  */
  71
  72 /* Fill GDB's register array with the general-purpose register values
  73    in *GREGSETP.  */
  74
  75 void
  76 supply_gregset (struct regcache *regcache, const elf_gregset_t * gregsetp)
  77 {
  78   const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
  79   int i;
  80   unsigned long psw, bbpsw;
  81
  82   psw = *(regp + PSW_REGMAP);
  83   bbpsw = *(regp + BBPSW_REGMAP);
  84
  85   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
  86     {
  87       elf_greg_t regval;
  88
  89       switch (i)
  90         {
  91         case PSW_REGNUM:
  92           regval = ((0x00c1 & bbpsw) << 8) | ((0xc100 & psw) >> 8);
  93           break;
  94         case CBR_REGNUM:
  95           regval = ((psw >> 8) & 1);
  96           break;
  97         default:
  98           regval = *(regp + regmap[i]);
  99           break;
 100         }
 101
 102       if (i != M32R_SP_REGNUM)
 103         regcache->raw_supply (i, &regval);
 104       else if (psw & 0x8000)
 105         regcache->raw_supply (i, regp + SPU_REGMAP);
 106       else
 107         regcache->raw_supply (i, regp + SPI_REGMAP);
 108     }
 109 }
 110
 111 /* Fetch all general-purpose registers from process/thread TID and
 112    store their values in GDB's register array.  */
 113
 114 static void
 115 fetch_regs (struct regcache *regcache, int tid)
 116 {
 117   elf_gregset_t regs;
 118
 119   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 120     perror_with_name (_("Couldn't get registers"));
 121
 122   supply_gregset (regcache, (const elf_gregset_t *) &regs);
 123 }
 124
 125 /* Fill register REGNO (if it is a general-purpose register) in
 126    *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
 127    do this for all registers.  */
 128
 129 void
 130 fill_gregset (const struct regcache *regcache,
 131               elf_gregset_t * gregsetp, int regno)
 132 {
 133   elf_greg_t *regp = (elf_greg_t *) gregsetp;
 134   int i;
 135   unsigned long psw, bbpsw, tmp;
 136
 137   psw = *(regp + PSW_REGMAP);
 138   bbpsw = *(regp + BBPSW_REGMAP);
 139
 140   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
 141     {
 142       if (regno != -1 && regno != i)
 143         continue;
 144
 145       if (i == CBR_REGNUM || i == PSW_REGNUM)
 146         continue;
 147
 148       if (i == SPU_REGNUM || i == SPI_REGNUM)
 149         continue;
 150
 151       if (i != M32R_SP_REGNUM)
 152         regcache->raw_collect (i, regp + regmap[i]);
 153       else if (psw & 0x8000)
 154         regcache->raw_collect (i, regp + SPU_REGMAP);
 155       else
 156         regcache->raw_collect (i, regp + SPI_REGMAP);
 157     }
 158 }
 159
 160 /* Store all valid general-purpose registers in GDB's register array
 161    into the process/thread specified by TID.  */
 162
 163 static void
 164 store_regs (const struct regcache *regcache, int tid, int regno)
 165 {
 166   elf_gregset_t regs;
 167
 168   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 169     perror_with_name (_("Couldn't get registers"));
 170
 171   fill_gregset (regcache, &regs, regno);
 172
 173   if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
 174     perror_with_name (_("Couldn't write registers"));
 175 }
 176 \f
 177
 178
 179 /* Transferring floating-point registers between GDB, inferiors and cores.
 180    Since M32R has no floating-point registers, these functions do nothing.  */
 181
 182 void
 183 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 184 {
 185 }
 186
 187 void
 188 fill_fpregset (const struct regcache *regcache,
 189                gdb_fpregset_t *fpregs, int regno)
 190 {
 191 }
 192 \f
 193
 194
 195 /* Transferring arbitrary registers between GDB and inferior.  */
 196
 197 /* Fetch register REGNO from the child process.  If REGNO is -1, do
 198    this for all registers (including the floating point and SSE
 199    registers).  */
 200
 201 void
 202 m32r_linux_nat_target::fetch_registers (struct regcache *regcache, int regno)
 203 {
 204   pid_t tid = get_ptrace_pid (regcache->ptid ());
 205
 206   /* Use the PTRACE_GETREGS request whenever possible, since it
 207      transfers more registers in one system call, and we'll cache the
 208      results.  */
 209   if (regno == -1 || GETREGS_SUPPLIES (regno))
 210     {
 211       fetch_regs (regcache, tid);
 212       return;
 213     }
 214
 215   internal_error (_("Got request for bad register number %d."), regno);
 216 }
 217
 218 /* Store register REGNO back into the child process.  If REGNO is -1,
 219    do this for all registers (including the floating point and SSE
 220    registers).  */
 221 void
 222 m32r_linux_nat_target::store_registers (struct regcache *regcache, int regno)
 223 {
 224   pid_t tid = get_ptrace_pid (regcache->ptid ());
 225
 226   /* Use the PTRACE_SETREGS request whenever possible, since it
 227      transfers more registers in one system call.  */
 228   if (regno == -1 || GETREGS_SUPPLIES (regno))
 229     {
 230       store_regs (regcache, tid, regno);
 231       return;
 232     }
 233
 234   internal_error (_("Got request to store bad register number %d."), regno);
 235 }
 236
 237 void _initialize_m32r_linux_nat ();
 238 void
 239 _initialize_m32r_linux_nat ()
 240 {
 241   /* Register the target.  */
 242   linux_target = &the_m32r_linux_nat_target;
 243   add_inf_child_target (&the_m32r_linux_nat_target);
 244 }