gdb/m32r-linux-nat.c

   1 /* Native-dependent code for GNU/Linux m32r.
   2
   3    Copyright (C) 2004-2016 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
  30 /* Prototypes for supply_gregset etc.  */
  31 #include "gregset.h"
  32
  33 #include "m32r-tdep.h"
  34 \f
  35
  36
  37
  38 /* Since EVB register is not available for native debug, we reduce
  39    the number of registers.  */
  40 #define M32R_LINUX_NUM_REGS (M32R_NUM_REGS - 1)
  41
  42 /* Mapping between the general-purpose registers in `struct user'
  43    format and GDB's register array layout.  */
  44 static int regmap[] = {
  45   4, 5, 6, 7, 0, 1, 2, 8,
  46   9, 10, 11, 12, 13, 24, 25, 23,
  47   19, 19, 26, 23, 22, 20, 16, 15
  48 };
  49
  50 #define PSW_REGMAP 19
  51 #define BBPSW_REGMAP 21
  52 #define SPU_REGMAP 23
  53 #define SPI_REGMAP 26
  54
  55 /* Doee (??) apply to the corresponding SET requests as well.  */
  56 #define GETREGS_SUPPLIES(regno) (0 <= (regno) \
  57                                  && (regno) <= M32R_LINUX_NUM_REGS)
  58 \f
  59
  60
  61 /* Transfering the general-purpose registers between GDB, inferiors
  62    and core files.  */
  63
  64 /* Fill GDB's register array with the general-purpose register values
  65    in *GREGSETP.  */
  66
  67 void
  68 supply_gregset (struct regcache *regcache, const elf_gregset_t * gregsetp)
  69 {
  70   const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
  71   int i;
  72   unsigned long psw, bbpsw;
  73
  74   psw = *(regp + PSW_REGMAP);
  75   bbpsw = *(regp + BBPSW_REGMAP);
  76
  77   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
  78     {
  79       elf_greg_t regval;
  80
  81       switch (i)
  82         {
  83         case PSW_REGNUM:
  84           regval = ((0x00c1 & bbpsw) << 8) | ((0xc100 & psw) >> 8);
  85           break;
  86         case CBR_REGNUM:
  87           regval = ((psw >> 8) & 1);
  88           break;
  89         default:
  90           regval = *(regp + regmap[i]);
  91           break;
  92         }
  93
  94       if (i != M32R_SP_REGNUM)
  95         regcache_raw_supply (regcache, i, &regval);
  96       else if (psw & 0x8000)
  97         regcache_raw_supply (regcache, i, regp + SPU_REGMAP);
  98       else
  99         regcache_raw_supply (regcache, i, regp + SPI_REGMAP);
 100     }
 101 }
 102
 103 /* Fetch all general-purpose registers from process/thread TID and
 104    store their values in GDB's register array.  */
 105
 106 static void
 107 fetch_regs (struct regcache *regcache, int tid)
 108 {
 109   elf_gregset_t regs;
 110
 111   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 112     perror_with_name (_("Couldn't get registers"));
 113
 114   supply_gregset (regcache, (const elf_gregset_t *) &regs);
 115 }
 116
 117 /* Fill register REGNO (if it is a general-purpose register) in
 118    *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
 119    do this for all registers.  */
 120
 121 void
 122 fill_gregset (const struct regcache *regcache,
 123               elf_gregset_t * gregsetp, int regno)
 124 {
 125   elf_greg_t *regp = (elf_greg_t *) gregsetp;
 126   int i;
 127   unsigned long psw, bbpsw, tmp;
 128
 129   psw = *(regp + PSW_REGMAP);
 130   bbpsw = *(regp + BBPSW_REGMAP);
 131
 132   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
 133     {
 134       if (regno != -1 && regno != i)
 135         continue;
 136
 137       if (i == CBR_REGNUM || i == PSW_REGNUM)
 138         continue;
 139
 140       if (i == SPU_REGNUM || i == SPI_REGNUM)
 141         continue;
 142
 143       if (i != M32R_SP_REGNUM)
 144         regcache_raw_collect (regcache, i, regp + regmap[i]);
 145       else if (psw & 0x8000)
 146         regcache_raw_collect (regcache, i, regp + SPU_REGMAP);
 147       else
 148         regcache_raw_collect (regcache, i, regp + SPI_REGMAP);
 149     }
 150 }
 151
 152 /* Store all valid general-purpose registers in GDB's register array
 153    into the process/thread specified by TID.  */
 154
 155 static void
 156 store_regs (const struct regcache *regcache, int tid, int regno)
 157 {
 158   elf_gregset_t regs;
 159
 160   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 161     perror_with_name (_("Couldn't get registers"));
 162
 163   fill_gregset (regcache, &regs, regno);
 164
 165   if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
 166     perror_with_name (_("Couldn't write registers"));
 167 }
 168 \f
 169
 170
 171 /* Transfering floating-point registers between GDB, inferiors and cores.
 172    Since M32R has no floating-point registers, these functions do nothing.  */
 173
 174 void
 175 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 176 {
 177 }
 178
 179 void
 180 fill_fpregset (const struct regcache *regcache,
 181                gdb_fpregset_t *fpregs, int regno)
 182 {
 183 }
 184 \f
 185
 186
 187 /* Transferring arbitrary registers between GDB and inferior.  */
 188
 189 /* Fetch register REGNO from the child process.  If REGNO is -1, do
 190    this for all registers (including the floating point and SSE
 191    registers).  */
 192
 193 static void
 194 m32r_linux_fetch_inferior_registers (struct target_ops *ops,
 195                                      struct regcache *regcache, int regno)
 196 {
 197   int tid;
 198
 199   /* GNU/Linux LWP ID's are process ID's.  */
 200   tid = ptid_get_lwp (inferior_ptid);
 201   if (tid == 0)
 202     tid = ptid_get_pid (inferior_ptid); /* Not a threaded program.  */
 203
 204   /* Use the PTRACE_GETREGS request whenever possible, since it
 205      transfers more registers in one system call, and we'll cache the
 206      results.  */
 207   if (regno == -1 || GETREGS_SUPPLIES (regno))
 208     {
 209       fetch_regs (regcache, tid);
 210       return;
 211     }
 212
 213   internal_error (__FILE__, __LINE__,
 214                   _("Got request for bad register number %d."), regno);
 215 }
 216
 217 /* Store register REGNO back into the child process.  If REGNO is -1,
 218    do this for all registers (including the floating point and SSE
 219    registers).  */
 220 static void
 221 m32r_linux_store_inferior_registers (struct target_ops *ops,
 222                                      struct regcache *regcache, int regno)
 223 {
 224   int tid;
 225
 226   /* GNU/Linux LWP ID's are process ID's.  */
 227   if ((tid = ptid_get_lwp (inferior_ptid)) == 0)
 228     tid = ptid_get_pid (inferior_ptid); /* Not a threaded program.  */
 229
 230   /* Use the PTRACE_SETREGS request whenever possible, since it
 231      transfers more registers in one system call.  */
 232   if (regno == -1 || GETREGS_SUPPLIES (regno))
 233     {
 234       store_regs (regcache, tid, regno);
 235       return;
 236     }
 237
 238   internal_error (__FILE__, __LINE__,
 239                   _("Got request to store bad register number %d."), regno);
 240 }
 241
 242 void _initialize_m32r_linux_nat (void);
 243
 244 void
 245 _initialize_m32r_linux_nat (void)
 246 {
 247   struct target_ops *t;
 248
 249   /* Fill in the generic GNU/Linux methods.  */
 250   t = linux_target ();
 251
 252   /* Add our register access methods.  */
 253   t->to_fetch_registers = m32r_linux_fetch_inferior_registers;
 254   t->to_store_registers = m32r_linux_store_inferior_registers;
 255
 256   /* Register the target.  */
 257   linux_nat_add_target (t);
 258 }