gdb/m32r-linux-nat.c

   1 /* Native-dependent code for GNU/Linux m32r.
   2
   3    Copyright (C) 2004-2013 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
  27 #include "gdb_assert.h"
  28 #include "gdb_string.h"
  29 #include <sys/ptrace.h>
  30 #include <sys/user.h>
  31 #include <sys/procfs.h>
  32
  33 /* Prototypes for supply_gregset etc.  */
  34 #include "gregset.h"
  35
  36 #include "m32r-tdep.h"
  37 \f
  38
  39
  40
  41 /* Since EVB register is not available for native debug, we reduce
  42    the number of registers.  */
  43 #define M32R_LINUX_NUM_REGS (M32R_NUM_REGS - 1)
  44
  45 /* Mapping between the general-purpose registers in `struct user'
  46    format and GDB's register array layout.  */
  47 static int regmap[] = {
  48   4, 5, 6, 7, 0, 1, 2, 8,
  49   9, 10, 11, 12, 13, 24, 25, 23,
  50   19, 19, 26, 23, 22, 20, 16, 15
  51 };
  52
  53 #define PSW_REGMAP 19
  54 #define BBPSW_REGMAP 21
  55 #define SPU_REGMAP 23
  56 #define SPI_REGMAP 26
  57
  58 /* Doee (??) apply to the corresponding SET requests as well.  */
  59 #define GETREGS_SUPPLIES(regno) (0 <= (regno) \
  60                                  && (regno) <= M32R_LINUX_NUM_REGS)
  61 \f
  62
  63
  64 /* Transfering the general-purpose registers between GDB, inferiors
  65    and core files.  */
  66
  67 /* Fill GDB's register array with the general-purpose register values
  68    in *GREGSETP.  */
  69
  70 void
  71 supply_gregset (struct regcache *regcache, const elf_gregset_t * gregsetp)
  72 {
  73   const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
  74   int i;
  75   unsigned long psw, bbpsw;
  76
  77   psw = *(regp + PSW_REGMAP);
  78   bbpsw = *(regp + BBPSW_REGMAP);
  79
  80   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
  81     {
  82       elf_greg_t regval;
  83
  84       switch (i)
  85         {
  86         case PSW_REGNUM:
  87           regval = ((0x00c1 & bbpsw) << 8) | ((0xc100 & psw) >> 8);
  88           break;
  89         case CBR_REGNUM:
  90           regval = ((psw >> 8) & 1);
  91           break;
  92         default:
  93           regval = *(regp + regmap[i]);
  94           break;
  95         }
  96
  97       if (i != M32R_SP_REGNUM)
  98         regcache_raw_supply (regcache, i, &regval);
  99       else if (psw & 0x8000)
 100         regcache_raw_supply (regcache, i, regp + SPU_REGMAP);
 101       else
 102         regcache_raw_supply (regcache, i, regp + SPI_REGMAP);
 103     }
 104 }
 105
 106 /* Fetch all general-purpose registers from process/thread TID and
 107    store their values in GDB's register array.  */
 108
 109 static void
 110 fetch_regs (struct regcache *regcache, int tid)
 111 {
 112   elf_gregset_t regs;
 113
 114   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 115     perror_with_name (_("Couldn't get registers"));
 116
 117   supply_gregset (regcache, (const elf_gregset_t *) &regs);
 118 }
 119
 120 /* Fill register REGNO (if it is a general-purpose register) in
 121    *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
 122    do this for all registers.  */
 123
 124 void
 125 fill_gregset (const struct regcache *regcache,
 126               elf_gregset_t * gregsetp, int regno)
 127 {
 128   elf_greg_t *regp = (elf_greg_t *) gregsetp;
 129   int i;
 130   unsigned long psw, bbpsw, tmp;
 131
 132   psw = *(regp + PSW_REGMAP);
 133   bbpsw = *(regp + BBPSW_REGMAP);
 134
 135   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
 136     {
 137       if (regno != -1 && regno != i)
 138         continue;
 139
 140       if (i == CBR_REGNUM || i == PSW_REGNUM)
 141         continue;
 142
 143       if (i == SPU_REGNUM || i == SPI_REGNUM)
 144         continue;
 145
 146       if (i != M32R_SP_REGNUM)
 147         regcache_raw_collect (regcache, i, regp + regmap[i]);
 148       else if (psw & 0x8000)
 149         regcache_raw_collect (regcache, i, regp + SPU_REGMAP);
 150       else
 151         regcache_raw_collect (regcache, i, regp + SPI_REGMAP);
 152     }
 153 }
 154
 155 /* Store all valid general-purpose registers in GDB's register array
 156    into the process/thread specified by TID.  */
 157
 158 static void
 159 store_regs (const struct regcache *regcache, int tid, int regno)
 160 {
 161   elf_gregset_t regs;
 162
 163   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 164     perror_with_name (_("Couldn't get registers"));
 165
 166   fill_gregset (regcache, &regs, regno);
 167
 168   if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
 169     perror_with_name (_("Couldn't write registers"));
 170 }
 171 \f
 172
 173
 174 /* Transfering floating-point registers between GDB, inferiors and cores.
 175    Since M32R has no floating-point registers, these functions do nothing.  */
 176
 177 void
 178 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 179 {
 180 }
 181
 182 void
 183 fill_fpregset (const struct regcache *regcache,
 184                gdb_fpregset_t *fpregs, int regno)
 185 {
 186 }
 187 \f
 188
 189
 190 /* Transferring arbitrary registers between GDB and inferior.  */
 191
 192 /* Fetch register REGNO from the child process.  If REGNO is -1, do
 193    this for all registers (including the floating point and SSE
 194    registers).  */
 195
 196 static void
 197 m32r_linux_fetch_inferior_registers (struct target_ops *ops,
 198                                      struct regcache *regcache, int regno)
 199 {
 200   int tid;
 201
 202   /* GNU/Linux LWP ID's are process ID's.  */
 203   tid = ptid_get_lwp (inferior_ptid);
 204   if (tid == 0)
 205     tid = ptid_get_pid (inferior_ptid); /* Not a threaded program.  */
 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 static void
 224 m32r_linux_store_inferior_registers (struct target_ops *ops,
 225                                      struct regcache *regcache, int regno)
 226 {
 227   int tid;
 228
 229   /* GNU/Linux LWP ID's are process ID's.  */
 230   if ((tid = ptid_get_lwp (inferior_ptid)) == 0)
 231     tid = ptid_get_pid (inferior_ptid); /* Not a threaded program.  */
 232
 233   /* Use the PTRACE_SETREGS request whenever possible, since it
 234      transfers more registers in one system call.  */
 235   if (regno == -1 || GETREGS_SUPPLIES (regno))
 236     {
 237       store_regs (regcache, tid, regno);
 238       return;
 239     }
 240
 241   internal_error (__FILE__, __LINE__,
 242                   _("Got request to store bad register number %d."), regno);
 243 }
 244
 245 void _initialize_m32r_linux_nat (void);
 246
 247 void
 248 _initialize_m32r_linux_nat (void)
 249 {
 250   struct target_ops *t;
 251
 252   /* Fill in the generic GNU/Linux methods.  */
 253   t = linux_target ();
 254
 255   /* Add our register access methods.  */
 256   t->to_fetch_registers = m32r_linux_fetch_inferior_registers;
 257   t->to_store_registers = m32r_linux_store_inferior_registers;
 258
 259   /* Register the target.  */
 260   linux_nat_add_target (t);
 261 }