gdb/m32r-linux-nat.c

   1 /* Native-dependent code for GNU/Linux m32r.
   2
   3    Copyright (C) 2004-2017 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
  38
  39 /* Since EVB register is not available for native debug, we reduce
  40    the number of registers.  */
  41 #define M32R_LINUX_NUM_REGS (M32R_NUM_REGS - 1)
  42
  43 /* Mapping between the general-purpose registers in `struct user'
  44    format and GDB's register array layout.  */
  45 static int regmap[] = {
  46   4, 5, 6, 7, 0, 1, 2, 8,
  47   9, 10, 11, 12, 13, 24, 25, 23,
  48   19, 19, 26, 23, 22, 20, 16, 15
  49 };
  50
  51 #define PSW_REGMAP 19
  52 #define BBPSW_REGMAP 21
  53 #define SPU_REGMAP 23
  54 #define SPI_REGMAP 26
  55
  56 /* Doee (??) apply to the corresponding SET requests as well.  */
  57 #define GETREGS_SUPPLIES(regno) (0 <= (regno) \
  58                                  && (regno) <= M32R_LINUX_NUM_REGS)
  59 \f
  60
  61
  62 /* Transfering the general-purpose registers between GDB, inferiors
  63    and core files.  */
  64
  65 /* Fill GDB's register array with the general-purpose register values
  66    in *GREGSETP.  */
  67
  68 void
  69 supply_gregset (struct regcache *regcache, const elf_gregset_t * gregsetp)
  70 {
  71   const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
  72   int i;
  73   unsigned long psw, bbpsw;
  74
  75   psw = *(regp + PSW_REGMAP);
  76   bbpsw = *(regp + BBPSW_REGMAP);
  77
  78   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
  79     {
  80       elf_greg_t regval;
  81
  82       switch (i)
  83         {
  84         case PSW_REGNUM:
  85           regval = ((0x00c1 & bbpsw) << 8) | ((0xc100 & psw) >> 8);
  86           break;
  87         case CBR_REGNUM:
  88           regval = ((psw >> 8) & 1);
  89           break;
  90         default:
  91           regval = *(regp + regmap[i]);
  92           break;
  93         }
  94
  95       if (i != M32R_SP_REGNUM)
  96         regcache_raw_supply (regcache, i, &regval);
  97       else if (psw & 0x8000)
  98         regcache_raw_supply (regcache, i, regp + SPU_REGMAP);
  99       else
 100         regcache_raw_supply (regcache, i, regp + SPI_REGMAP);
 101     }
 102 }
 103
 104 /* Fetch all general-purpose registers from process/thread TID and
 105    store their values in GDB's register array.  */
 106
 107 static void
 108 fetch_regs (struct regcache *regcache, int tid)
 109 {
 110   elf_gregset_t regs;
 111
 112   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 113     perror_with_name (_("Couldn't get registers"));
 114
 115   supply_gregset (regcache, (const elf_gregset_t *) &regs);
 116 }
 117
 118 /* Fill register REGNO (if it is a general-purpose register) in
 119    *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
 120    do this for all registers.  */
 121
 122 void
 123 fill_gregset (const struct regcache *regcache,
 124               elf_gregset_t * gregsetp, int regno)
 125 {
 126   elf_greg_t *regp = (elf_greg_t *) gregsetp;
 127   int i;
 128   unsigned long psw, bbpsw, tmp;
 129
 130   psw = *(regp + PSW_REGMAP);
 131   bbpsw = *(regp + BBPSW_REGMAP);
 132
 133   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
 134     {
 135       if (regno != -1 && regno != i)
 136         continue;
 137
 138       if (i == CBR_REGNUM || i == PSW_REGNUM)
 139         continue;
 140
 141       if (i == SPU_REGNUM || i == SPI_REGNUM)
 142         continue;
 143
 144       if (i != M32R_SP_REGNUM)
 145         regcache_raw_collect (regcache, i, regp + regmap[i]);
 146       else if (psw & 0x8000)
 147         regcache_raw_collect (regcache, i, regp + SPU_REGMAP);
 148       else
 149         regcache_raw_collect (regcache, i, regp + SPI_REGMAP);
 150     }
 151 }
 152
 153 /* Store all valid general-purpose registers in GDB's register array
 154    into the process/thread specified by TID.  */
 155
 156 static void
 157 store_regs (const struct regcache *regcache, int tid, int regno)
 158 {
 159   elf_gregset_t regs;
 160
 161   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
 162     perror_with_name (_("Couldn't get registers"));
 163
 164   fill_gregset (regcache, &regs, regno);
 165
 166   if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
 167     perror_with_name (_("Couldn't write registers"));
 168 }
 169 \f
 170
 171
 172 /* Transfering floating-point registers between GDB, inferiors and cores.
 173    Since M32R has no floating-point registers, these functions do nothing.  */
 174
 175 void
 176 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
 177 {
 178 }
 179
 180 void
 181 fill_fpregset (const struct regcache *regcache,
 182                gdb_fpregset_t *fpregs, int regno)
 183 {
 184 }
 185 \f
 186
 187
 188 /* Transferring arbitrary registers between GDB and inferior.  */
 189
 190 /* Fetch register REGNO from the child process.  If REGNO is -1, do
 191    this for all registers (including the floating point and SSE
 192    registers).  */
 193
 194 static void
 195 m32r_linux_fetch_inferior_registers (struct target_ops *ops,
 196                                      struct regcache *regcache, int regno)
 197 {
 198   pid_t tid = get_ptrace_pid (regcache_get_ptid (regcache));
 199
 200   /* Use the PTRACE_GETREGS request whenever possible, since it
 201      transfers more registers in one system call, and we'll cache the
 202      results.  */
 203   if (regno == -1 || GETREGS_SUPPLIES (regno))
 204     {
 205       fetch_regs (regcache, tid);
 206       return;
 207     }
 208
 209   internal_error (__FILE__, __LINE__,
 210                   _("Got request for bad register number %d."), regno);
 211 }
 212
 213 /* Store register REGNO back into the child process.  If REGNO is -1,
 214    do this for all registers (including the floating point and SSE
 215    registers).  */
 216 static void
 217 m32r_linux_store_inferior_registers (struct target_ops *ops,
 218                                      struct regcache *regcache, int regno)
 219 {
 220   pid_t tid = get_ptrace_pid (regcache_get_ptid (regcache));
 221
 222   /* Use the PTRACE_SETREGS request whenever possible, since it
 223      transfers more registers in one system call.  */
 224   if (regno == -1 || GETREGS_SUPPLIES (regno))
 225     {
 226       store_regs (regcache, tid, regno);
 227       return;
 228     }
 229
 230   internal_error (__FILE__, __LINE__,
 231                   _("Got request to store bad register number %d."), regno);
 232 }
 233
 234 void _initialize_m32r_linux_nat (void);
 235
 236 void
 237 _initialize_m32r_linux_nat (void)
 238 {
 239   struct target_ops *t;
 240
 241   /* Fill in the generic GNU/Linux methods.  */
 242   t = linux_target ();
 243
 244   /* Add our register access methods.  */
 245   t->to_fetch_registers = m32r_linux_fetch_inferior_registers;
 246   t->to_store_registers = m32r_linux_store_inferior_registers;
 247
 248   /* Register the target.  */
 249   linux_nat_add_target (t);
 250 }