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   bool low_breakpoint_at (CORE_ADDR pc) override;
  48 };
  49
  50 /* The singleton target ops object.  */
  51
  52 static cris_target the_cris_target;
  53
  54 bool
  55 cris_target::low_supports_breakpoints ()
  56 {
  57   return true;
  58 }
  59
  60 CORE_ADDR
  61 cris_target::low_get_pc (regcache *regcache)
  62 {
  63   return linux_get_pc_32bit (regcache);
  64 }
  65
  66 void
  67 cris_target::low_set_pc (regcache *regcache, CORE_ADDR pc)
  68 {
  69   linux_set_pc_32bit (regcache, pc);
  70 }
  71
  72 /* Defined in auto-generated file reg-cris.c.  */
  73 void init_registers_cris (void);
  74 extern const struct target_desc *tdesc_cris;
  75
  76 /* CRISv10 */
  77 #define cris_num_regs 32
  78
  79 /* Locations need to match <include/asm/arch/ptrace.h>.  */
  80 static int cris_regmap[] = {
  81   15*4, 14*4, 13*4, 12*4,
  82   11*4, 10*4, 9*4, 8*4,
  83   7*4, 6*4, 5*4, 4*4,
  84   3*4, 2*4, 23*4, 19*4,
  85
  86   -1, -1, -1, -1,
  87   -1, 17*4, -1, 16*4,
  88   -1, -1, -1, 18*4,
  89   -1, 17*4, -1, -1
  90
  91 };
  92
  93 bool
  94 cris_target::low_cannot_store_register (int regno)
  95 {
  96   if (cris_regmap[regno] == -1)
  97     return true;
  98
  99   return (regno >= cris_num_regs);
 100 }
 101
 102 bool
 103 cris_target::low_cannot_fetch_register (int regno)
 104 {
 105   if (cris_regmap[regno] == -1)
 106     return true;
 107
 108   return (regno >= cris_num_regs);
 109 }
 110
 111 static const unsigned short cris_breakpoint = 0xe938;
 112 #define cris_breakpoint_len 2
 113
 114 /* Implementation of target ops method "sw_breakpoint_from_kind".  */
 115
 116 const gdb_byte *
 117 cris_target::sw_breakpoint_from_kind (int kind, int *size)
 118 {
 119   *size = cris_breakpoint_len;
 120   return (const gdb_byte *) &cris_breakpoint;
 121 }
 122
 123 bool
 124 cris_target::low_breakpoint_at (CORE_ADDR where)
 125 {
 126   unsigned short insn;
 127
 128   read_memory (where, (unsigned char *) &insn, cris_breakpoint_len);
 129   if (insn == cris_breakpoint)
 130     return true;
 131
 132   /* If necessary, recognize more trap instructions here.  GDB only uses the
 133      one.  */
 134   return false;
 135 }
 136
 137 void
 138 cris_target::low_arch_setup ()
 139 {
 140   current_process ()->tdesc = tdesc_cris;
 141 }
 142
 143 static struct usrregs_info cris_usrregs_info =
 144   {
 145     cris_num_regs,
 146     cris_regmap,
 147   };
 148
 149 static struct regs_info myregs_info =
 150   {
 151     NULL, /* regset_bitmap */
 152     &cris_usrregs_info,
 153   };
 154
 155 const regs_info *
 156 cris_target::get_regs_info ()
 157 {
 158   return &myregs_info;
 159 }
 160
 161 /* The linux target ops object.  */
 162
 163 linux_process_target *the_linux_target = &the_cris_target;
 164
 165 void
 166 initialize_low_arch (void)
 167 {
 168   init_registers_cris ();
 169 }