gdbserver/linux-cris-low.cc

   1 /* GNU/Linux/CRIS specific low level interface, for the remote server for GDB.
   2    Copyright (C) 1995-2020 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include "server.h"
  20 #include "linux-low.h"
  21 #include "nat/gdb_ptrace.h"
  22
  23 /* Linux target op definitions for the CRIS architecture.  */
  24
  25 class cris_target : public linux_process_target
  26 {
  27 public:
  28
  29   const regs_info *get_regs_info () override;
  30
  31   const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override;
  32
  33 protected:
  34
  35   void low_arch_setup () override;
  36
  37   bool low_cannot_fetch_register (int regno) override;
  38
  39   bool low_cannot_store_register (int regno) override;
  40
  41   bool low_supports_breakpoints () override;
  42
  43   CORE_ADDR low_get_pc (regcache *regcache) override;
  44
  45   void low_set_pc (regcache *regcache, CORE_ADDR newpc) override;
  46 };
  47
  48 /* The singleton target ops object.  */
  49
  50 static cris_target the_cris_target;
  51
  52 bool
  53 cris_target::low_supports_breakpoints ()
  54 {
  55   return true;
  56 }
  57
  58 CORE_ADDR
  59 cris_target::low_get_pc (regcache *regcache)
  60 {
  61   return linux_get_pc_32bit (regcache);
  62 }
  63
  64 void
  65 cris_target::low_set_pc (regcache *regcache, CORE_ADDR pc)
  66 {
  67   linux_set_pc_32bit (regcache, pc);
  68 }
  69
  70 /* Defined in auto-generated file reg-cris.c.  */
  71 void init_registers_cris (void);
  72 extern const struct target_desc *tdesc_cris;
  73
  74 /* CRISv10 */
  75 #define cris_num_regs 32
  76
  77 /* Locations need to match <include/asm/arch/ptrace.h>.  */
  78 static int cris_regmap[] = {
  79   15*4, 14*4, 13*4, 12*4,
  80   11*4, 10*4, 9*4, 8*4,
  81   7*4, 6*4, 5*4, 4*4,
  82   3*4, 2*4, 23*4, 19*4,
  83
  84   -1, -1, -1, -1,
  85   -1, 17*4, -1, 16*4,
  86   -1, -1, -1, 18*4,
  87   -1, 17*4, -1, -1
  88
  89 };
  90
  91 bool
  92 cris_target::low_cannot_store_register (int regno)
  93 {
  94   if (cris_regmap[regno] == -1)
  95     return true;
  96
  97   return (regno >= cris_num_regs);
  98 }
  99
 100 bool
 101 cris_target::low_cannot_fetch_register (int regno)
 102 {
 103   if (cris_regmap[regno] == -1)
 104     return true;
 105
 106   return (regno >= cris_num_regs);
 107 }
 108
 109 static const unsigned short cris_breakpoint = 0xe938;
 110 #define cris_breakpoint_len 2
 111
 112 /* Implementation of target ops method "sw_breakpoint_from_kind".  */
 113
 114 const gdb_byte *
 115 cris_target::sw_breakpoint_from_kind (int kind, int *size)
 116 {
 117   *size = cris_breakpoint_len;
 118   return (const gdb_byte *) &cris_breakpoint;
 119 }
 120
 121 static int
 122 cris_breakpoint_at (CORE_ADDR where)
 123 {
 124   unsigned short insn;
 125
 126   the_target->read_memory (where, (unsigned char *) &insn,
 127                            cris_breakpoint_len);
 128   if (insn == cris_breakpoint)
 129     return 1;
 130
 131   /* If necessary, recognize more trap instructions here.  GDB only uses the
 132      one.  */
 133   return 0;
 134 }
 135
 136 void
 137 cris_target::low_arch_setup ()
 138 {
 139   current_process ()->tdesc = tdesc_cris;
 140 }
 141
 142 static struct usrregs_info cris_usrregs_info =
 143   {
 144     cris_num_regs,
 145     cris_regmap,
 146   };
 147
 148 static struct regs_info myregs_info =
 149   {
 150     NULL, /* regset_bitmap */
 151     &cris_usrregs_info,
 152   };
 153
 154 const regs_info *
 155 cris_target::get_regs_info ()
 156 {
 157   return &myregs_info;
 158 }
 159
 160 struct linux_target_ops the_low_target = {
 161   0,
 162   cris_breakpoint_at,
 163 };
 164
 165 /* The linux target ops object.  */
 166
 167 linux_process_target *the_linux_target = &the_cris_target;
 168
 169 void
 170 initialize_low_arch (void)
 171 {
 172   init_registers_cris ();
 173 }