gdb/m32r-linux-nat.c

   1 /* Native-dependent code for GNU/Linux m32r.
   2
   3    Copyright (C) 2004-2020 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 "defs.h"
  21 #include "inferior.h"
  22 #include "gdbcore.h"
  23 #include "regcache.h"
  24 #include "linux-nat.h"
  25 #include "target.h"
  26 #include "nat/gdb_ptrace.h"
  27 #include <sys/user.h>
  28 #include <sys/procfs.h>
  29 #include "inf-ptrace.h"
  30
  31 /* Prototypes for supply_gregset etc.  */
  32 #include "gregset.h"
  33
  34 #include "m32r-tdep.h"
  35 \f
  36
  37 class m32r_linux_nat_target final : public linux_nat_target
  38 {
  39 public:
  40   /* Add our register access methods.  */
  41   void fetch_registers (struct regcache *, int) override;
  42   void store_registers (struct regcache *, int) override;
  43 };
  44
  45 static m32r_linux_nat_target the_m32r_linux_nat_target;
  46
  47 /* Since EVB register is not available for native debug, we reduce
  48    the number of registers.  */
  49 #define M32R_LINUX_NUM_REGS (M32R_NUM_REGS - 1)
  50
  51 /* Mapping between the general-purpose registers in `struct user'
  52    format and GDB's register array layout.  */
  53 static int regmap[] = {
  54   4, 5, 6, 7, 0, 1, 2, 8,
  55   9, 10, 11, 12, 13, 24, 25, 23,
  56   19, 19, 26, 23, 22, 20, 16, 15
  57 };
  58
  59 #define PSW_REGMAP 19
  60 #define BBPSW_REGMAP 21
  61 #define SPU_REGMAP 23
  62 #define SPI_REGMAP 26
  63
  64 /* Doee (??) apply to the corresponding SET requests as well.  */
  65 #define GETREGS_SUPPLIES(regno) (0 <= (regno) \
  66                                  && (regno) <= M32R_LINUX_NUM_REGS)
  67 \f
  68
  69
  70 /* Transfering the general-purpose registers between GDB, inferiors
  71    and core files.  */
  72
  73 /* Fill GDB's register array with the general-purpose register values
  74    in *GREGSETP.  */
  75
  76 void
  77 supply_gregset (struct regcache *regcache, const elf_gregset_t * gregsetp)
  78 {
  79   const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
  80   int i;
  81   unsigned long psw, bbpsw;
  82
  83   psw = *(regp + PSW_REGMAP);
  84   bbpsw = *(regp + BBPSW_REGMAP);
  85
  86   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
  87     {
  88       elf_greg_t regval;
  89
  90       switch (i)
  91         {
  92         case PSW_REGNUM:
  93           regval = ((0x00c1 & bbpsw) << 8) | ((0xc100 & psw) >> 8);
  94           break;
  95         case CBR_REGNUM:
  96           regval = ((psw >> 8) & 1);
  97           break;
  98         default:
  99           regval = *(regp + regmap[i]);
 100           break;
 101         }
 102
 103       if (i != M32R_SP_REGNUM)
 104         regcache->raw_supply (i, &regval);
 105       else if (psw & 0x8000)
 106         regcache->raw_supply (i, regp + SPU_REGMAP);
 107       else
 108         regcache->raw_supply (i, regp + SPI_REGMAP);
 109     }
 110 }
 111
 112 /* Fetch all general-purpose registers from process/thread TID and
 113    store their values in GDB's register array.  */
 114
 115 static void
 116 fetch_regs (struct regcache *regcache, int tid)
 117 {
 118   elf_gregset_t regs;
 119
 120   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 121     perror_with_name (_("Couldn't get registers"));
 122
 123   supply_gregset (regcache, (const elf_gregset_t *) &regs);
 124 }
 125
 126 /* Fill register REGNO (if it is a general-purpose register) in
 127    *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
 128    do this for all registers.  */
 129
 130 void
 131 fill_gregset (const struct regcache *regcache,
 132               elf_gregset_t * gregsetp, int regno)
 133 {
 134   elf_greg_t *regp = (elf_greg_t *) gregsetp;
 135   int i;
 136   unsigned long psw, bbpsw, tmp;
 137
 138   psw = *(regp + PSW_REGMAP);
 139   bbpsw = *(regp + BBPSW_REGMAP);
 140
 141   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
 142     {
 143       if (regno != -1 && regno != i)
 144         continue;
 145
 146       if (i == CBR_REGNUM || i == PSW_REGNUM)
 147         continue;
 148
 149       if (i == SPU_REGNUM || i == SPI_REGNUM)
 150         continue;
 151
 152       if (i != M32R_SP_REGNUM)
 153         regcache->raw_collect (i, regp + regmap[i]);
 154       else if (psw & 0x8000)
 155         regcache->raw_collect (i, regp + SPU_REGMAP);
 156       else
 157         regcache->raw_collect (i, regp + SPI_REGMAP);
 158     }
 159 }
 160
 161 /* Store all valid general-purpose registers in GDB's register array
 162    into the process/thread specified by TID.  */
 163
 164 static void
 165 store_regs (const struct regcache *regcache, int tid, int regno)
 166 {
 167   elf_gregset_t regs;
 168
 169   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 170     perror_with_name (_("Couldn't get registers"));
 171
 172   fill_gregset (regcache, &regs, regno);
 173
 174   if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
 175     perror_with_name (_("Couldn't write registers"));
 176 }
 177 \f
 178
 179
 180 /* Transfering floating-point registers between GDB, inferiors and cores.
 181    Since M32R has no floating-point registers, these functions do nothing.  */
 182
 183 void
 184 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 185 {
 186 }
 187
 188 void
 189 fill_fpregset (const struct regcache *regcache,
 190                gdb_fpregset_t *fpregs, int regno)
 191 {
 192 }
 193 \f
 194
 195
 196 /* Transferring arbitrary registers between GDB and inferior.  */
 197
 198 /* Fetch register REGNO from the child process.  If REGNO is -1, do
 199    this for all registers (including the floating point and SSE
 200    registers).  */
 201
 202 void
 203 m32r_linux_nat_target::fetch_registers (struct regcache *regcache, int regno)
 204 {
 205   pid_t tid = get_ptrace_pid (regcache->ptid ());
 206
 207   /* Use the PTRACE_GETREGS request whenever possible, since it
 208      transfers more registers in one system call, and we'll cache the
 209      results.  */
 210   if (regno == -1 || GETREGS_SUPPLIES (regno))
 211     {
 212       fetch_regs (regcache, tid);
 213       return;
 214     }
 215
 216   internal_error (__FILE__, __LINE__,
 217                   _("Got request for bad register number %d."), regno);
 218 }
 219
 220 /* Store register REGNO back into the child process.  If REGNO is -1,
 221    do this for all registers (including the floating point and SSE
 222    registers).  */
 223 void
 224 m32r_linux_nat_target::store_registers (struct regcache *regcache, int regno)
 225 {
 226   pid_t tid = get_ptrace_pid (regcache->ptid ());
 227
 228   /* Use the PTRACE_SETREGS request whenever possible, since it
 229      transfers more registers in one system call.  */
 230   if (regno == -1 || GETREGS_SUPPLIES (regno))
 231     {
 232       store_regs (regcache, tid, regno);
 233       return;
 234     }
 235
 236   internal_error (__FILE__, __LINE__,
 237                   _("Got request to store bad register number %d."), regno);
 238 }
 239
 240 void
 241 _initialize_m32r_linux_nat (void)
 242 {
 243   /* Register the target.  */
 244   linux_target = &the_m32r_linux_nat_target;
 245   add_inf_child_target (&the_m32r_linux_nat_target);
 246 }