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 protected:
  32
  33   void low_arch_setup () override;
  34 };
  35
  36 /* The singleton target ops object.  */
  37
  38 static cris_target the_cris_target;
  39
  40 /* Defined in auto-generated file reg-cris.c.  */
  41 void init_registers_cris (void);
  42 extern const struct target_desc *tdesc_cris;
  43
  44 /* CRISv10 */
  45 #define cris_num_regs 32
  46
  47 /* Locations need to match <include/asm/arch/ptrace.h>.  */
  48 static int cris_regmap[] = {
  49   15*4, 14*4, 13*4, 12*4,
  50   11*4, 10*4, 9*4, 8*4,
  51   7*4, 6*4, 5*4, 4*4,
  52   3*4, 2*4, 23*4, 19*4,
  53
  54   -1, -1, -1, -1,
  55   -1, 17*4, -1, 16*4,
  56   -1, -1, -1, 18*4,
  57   -1, 17*4, -1, -1
  58
  59 };
  60
  61 static int
  62 cris_cannot_store_register (int regno)
  63 {
  64   if (cris_regmap[regno] == -1)
  65     return 1;
  66
  67   return (regno >= cris_num_regs);
  68 }
  69
  70 static int
  71 cris_cannot_fetch_register (int regno)
  72 {
  73   if (cris_regmap[regno] == -1)
  74     return 1;
  75
  76   return (regno >= cris_num_regs);
  77 }
  78
  79 static const unsigned short cris_breakpoint = 0xe938;
  80 #define cris_breakpoint_len 2
  81
  82 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
  83
  84 static const gdb_byte *
  85 cris_sw_breakpoint_from_kind (int kind, int *size)
  86 {
  87   *size = cris_breakpoint_len;
  88   return (const gdb_byte *) &cris_breakpoint;
  89 }
  90
  91 static int
  92 cris_breakpoint_at (CORE_ADDR where)
  93 {
  94   unsigned short insn;
  95
  96   the_target->read_memory (where, (unsigned char *) &insn,
  97                            cris_breakpoint_len);
  98   if (insn == cris_breakpoint)
  99     return 1;
 100
 101   /* If necessary, recognize more trap instructions here.  GDB only uses the
 102      one.  */
 103   return 0;
 104 }
 105
 106 void
 107 cris_target::low_arch_setup ()
 108 {
 109   current_process ()->tdesc = tdesc_cris;
 110 }
 111
 112 static struct usrregs_info cris_usrregs_info =
 113   {
 114     cris_num_regs,
 115     cris_regmap,
 116   };
 117
 118 static struct regs_info myregs_info =
 119   {
 120     NULL, /* regset_bitmap */
 121     &cris_usrregs_info,
 122   };
 123
 124 const regs_info *
 125 cris_target::get_regs_info ()
 126 {
 127   return &myregs_info;
 128 }
 129
 130 struct linux_target_ops the_low_target = {
 131   cris_cannot_fetch_register,
 132   cris_cannot_store_register,
 133   NULL, /* fetch_register */
 134   linux_get_pc_32bit,
 135   linux_set_pc_32bit,
 136   NULL, /* breakpoint_kind_from_pc */
 137   cris_sw_breakpoint_from_kind,
 138   NULL, /* get_next_pcs */
 139   0,
 140   cris_breakpoint_at,
 141 };
 142
 143 /* The linux target ops object.  */
 144
 145 linux_process_target *the_linux_target = &the_cris_target;
 146
 147 void
 148 initialize_low_arch (void)
 149 {
 150   init_registers_cris ();
 151 }