gdb/m32r-linux-nat.c

   1 /* Native-dependent code for GNU/Linux m32r.
   2
   3    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "inferior.h"
  23 #include "gdbcore.h"
  24 #include "regcache.h"
  25 #include "linux-nat.h"
  26 #include "target.h"
  27
  28 #include "gdb_assert.h"
  29 #include "gdb_string.h"
  30 #include <sys/ptrace.h>
  31 #include <sys/user.h>
  32 #include <sys/procfs.h>
  33
  34 /* Prototypes for supply_gregset etc.  */
  35 #include "gregset.h"
  36
  37 #include "m32r-tdep.h"
  38 \f
  39
  40
  41
  42 /* Since EVB register is not available for native debug, we reduce
  43    the number of registers.  */
  44 #define M32R_LINUX_NUM_REGS (M32R_NUM_REGS - 1)
  45
  46 /* Mapping between the general-purpose registers in `struct user'
  47    format and GDB's register array layout.  */
  48 static int regmap[] = {
  49   4, 5, 6, 7, 0, 1, 2, 8,
  50   9, 10, 11, 12, 13, 24, 25, 23,
  51   19, 19, 26, 23, 22, 20, 16, 15
  52 };
  53
  54 #define PSW_REGMAP 19
  55 #define BBPSW_REGMAP 21
  56 #define SPU_REGMAP 23
  57 #define SPI_REGMAP 26
  58
  59 /* Doee (??) apply to the corresponding SET requests as well.  */
  60 #define GETREGS_SUPPLIES(regno) (0 <= (regno) \
  61                                  && (regno) <= M32R_LINUX_NUM_REGS)
  62 \f
  63
  64
  65 /* Transfering the general-purpose registers between GDB, inferiors
  66    and core files.  */
  67
  68 /* Fill GDB's register array with the general-purpose register values
  69    in *GREGSETP.  */
  70
  71 void
  72 supply_gregset (struct regcache *regcache, const elf_gregset_t * gregsetp)
  73 {
  74   const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
  75   int i;
  76   unsigned long psw, bbpsw;
  77
  78   psw = *(regp + PSW_REGMAP);
  79   bbpsw = *(regp + BBPSW_REGMAP);
  80
  81   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
  82     {
  83       elf_greg_t regval;
  84
  85       switch (i)
  86         {
  87         case PSW_REGNUM:
  88           regval = ((0x00c1 & bbpsw) << 8) | ((0xc100 & psw) >> 8);
  89           break;
  90         case CBR_REGNUM:
  91           regval = ((psw >> 8) & 1);
  92           break;
  93         default:
  94           regval = *(regp + regmap[i]);
  95           break;
  96         }
  97
  98       if (i != M32R_SP_REGNUM)
  99         regcache_raw_supply (regcache, i, &regval);
 100       else if (psw & 0x8000)
 101         regcache_raw_supply (regcache, i, regp + SPU_REGMAP);
 102       else
 103         regcache_raw_supply (regcache, i, regp + SPI_REGMAP);
 104     }
 105 }
 106
 107 /* Fetch all general-purpose registers from process/thread TID and
 108    store their values in GDB's register array.  */
 109
 110 static void
 111 fetch_regs (struct regcache *regcache, int tid)
 112 {
 113   elf_gregset_t regs;
 114
 115   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 116     perror_with_name (_("Couldn't get registers"));
 117
 118   supply_gregset (regcache, (const elf_gregset_t *) &regs);
 119 }
 120
 121 /* Fill register REGNO (if it is a general-purpose register) in
 122    *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
 123    do this for all registers.  */
 124
 125 void
 126 fill_gregset (const struct regcache *regcache,
 127               elf_gregset_t * gregsetp, int regno)
 128 {
 129   elf_greg_t *regp = (elf_greg_t *) gregsetp;
 130   int i;
 131   unsigned long psw, bbpsw, tmp;
 132
 133   psw = *(regp + PSW_REGMAP);
 134   bbpsw = *(regp + BBPSW_REGMAP);
 135
 136   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
 137     {
 138       if (regno != -1 && regno != i)
 139         continue;
 140
 141       if (i == CBR_REGNUM || i == PSW_REGNUM)
 142         continue;
 143
 144       if (i == SPU_REGNUM || i == SPI_REGNUM)
 145         continue;
 146
 147       if (i != M32R_SP_REGNUM)
 148         regcache_raw_collect (regcache, i, regp + regmap[i]);
 149       else if (psw & 0x8000)
 150         regcache_raw_collect (regcache, i, regp + SPU_REGMAP);
 151       else
 152         regcache_raw_collect (regcache, i, regp + SPI_REGMAP);
 153     }
 154 }
 155
 156 /* Store all valid general-purpose registers in GDB's register array
 157    into the process/thread specified by TID.  */
 158
 159 static void
 160 store_regs (const struct regcache *regcache, int tid, int regno)
 161 {
 162   elf_gregset_t regs;
 163
 164   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 165     perror_with_name (_("Couldn't get registers"));
 166
 167   fill_gregset (regcache, &regs, regno);
 168
 169   if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
 170     perror_with_name (_("Couldn't write registers"));
 171 }
 172 \f
 173
 174
 175 /* Transfering floating-point registers between GDB, inferiors and cores.
 176    Since M32R has no floating-point registers, these functions do nothing.  */
 177
 178 void
 179 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 180 {
 181 }
 182
 183 void
 184 fill_fpregset (const struct regcache *regcache,
 185                gdb_fpregset_t *fpregs, int regno)
 186 {
 187 }
 188 \f
 189
 190
 191 /* Transferring arbitrary registers between GDB and inferior.  */
 192
 193 /* Fetch register REGNO from the child process.  If REGNO is -1, do
 194    this for all registers (including the floating point and SSE
 195    registers).  */
 196
 197 static void
 198 m32r_linux_fetch_inferior_registers (struct target_ops *ops,
 199                                      struct regcache *regcache, int regno)
 200 {
 201   int tid;
 202
 203   /* GNU/Linux LWP ID's are process ID's.  */
 204   tid = TIDGET (inferior_ptid);
 205   if (tid == 0)
 206     tid = PIDGET (inferior_ptid);       /* Not a threaded program.  */
 207
 208   /* Use the PTRACE_GETREGS request whenever possible, since it
 209      transfers more registers in one system call, and we'll cache the
 210      results.  */
 211   if (regno == -1 || GETREGS_SUPPLIES (regno))
 212     {
 213       fetch_regs (regcache, tid);
 214       return;
 215     }
 216
 217   internal_error (__FILE__, __LINE__,
 218                   _("Got request for bad register number %d."), regno);
 219 }
 220
 221 /* Store register REGNO back into the child process.  If REGNO is -1,
 222    do this for all registers (including the floating point and SSE
 223    registers).  */
 224 static void
 225 m32r_linux_store_inferior_registers (struct target_ops *ops,
 226                                      struct regcache *regcache, int regno)
 227 {
 228   int tid;
 229
 230   /* GNU/Linux LWP ID's are process ID's.  */
 231   if ((tid = TIDGET (inferior_ptid)) == 0)
 232     tid = PIDGET (inferior_ptid);       /* Not a threaded program.  */
 233
 234   /* Use the PTRACE_SETREGS request whenever possible, since it
 235      transfers more registers in one system call.  */
 236   if (regno == -1 || GETREGS_SUPPLIES (regno))
 237     {
 238       store_regs (regcache, tid, regno);
 239       return;
 240     }
 241
 242   internal_error (__FILE__, __LINE__,
 243                   _("Got request to store bad register number %d."), regno);
 244 }
 245
 246 void _initialize_m32r_linux_nat (void);
 247
 248 void
 249 _initialize_m32r_linux_nat (void)
 250 {
 251   struct target_ops *t;
 252
 253   /* Fill in the generic GNU/Linux methods.  */
 254   t = linux_target ();
 255
 256   /* Add our register access methods.  */
 257   t->to_fetch_registers = m32r_linux_fetch_inferior_registers;
 258   t->to_store_registers = m32r_linux_store_inferior_registers;
 259
 260   /* Register the target.  */
 261   linux_nat_add_target (t);
 262 }