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 };
  30
  31 /* The singleton target ops object.  */
  32
  33 static cris_target the_cris_target;
  34
  35 /* Defined in auto-generated file reg-cris.c.  */
  36 void init_registers_cris (void);
  37 extern const struct target_desc *tdesc_cris;
  38
  39 /* CRISv10 */
  40 #define cris_num_regs 32
  41
  42 /* Locations need to match <include/asm/arch/ptrace.h>.  */
  43 static int cris_regmap[] = {
  44   15*4, 14*4, 13*4, 12*4,
  45   11*4, 10*4, 9*4, 8*4,
  46   7*4, 6*4, 5*4, 4*4,
  47   3*4, 2*4, 23*4, 19*4,
  48
  49   -1, -1, -1, -1,
  50   -1, 17*4, -1, 16*4,
  51   -1, -1, -1, 18*4,
  52   -1, 17*4, -1, -1
  53
  54 };
  55
  56 static int
  57 cris_cannot_store_register (int regno)
  58 {
  59   if (cris_regmap[regno] == -1)
  60     return 1;
  61
  62   return (regno >= cris_num_regs);
  63 }
  64
  65 static int
  66 cris_cannot_fetch_register (int regno)
  67 {
  68   if (cris_regmap[regno] == -1)
  69     return 1;
  70
  71   return (regno >= cris_num_regs);
  72 }
  73
  74 static const unsigned short cris_breakpoint = 0xe938;
  75 #define cris_breakpoint_len 2
  76
  77 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
  78
  79 static const gdb_byte *
  80 cris_sw_breakpoint_from_kind (int kind, int *size)
  81 {
  82   *size = cris_breakpoint_len;
  83   return (const gdb_byte *) &cris_breakpoint;
  84 }
  85
  86 static int
  87 cris_breakpoint_at (CORE_ADDR where)
  88 {
  89   unsigned short insn;
  90
  91   the_target->read_memory (where, (unsigned char *) &insn,
  92                            cris_breakpoint_len);
  93   if (insn == cris_breakpoint)
  94     return 1;
  95
  96   /* If necessary, recognize more trap instructions here.  GDB only uses the
  97      one.  */
  98   return 0;
  99 }
 100
 101 static void
 102 cris_arch_setup (void)
 103 {
 104   current_process ()->tdesc = tdesc_cris;
 105 }
 106
 107 static struct usrregs_info cris_usrregs_info =
 108   {
 109     cris_num_regs,
 110     cris_regmap,
 111   };
 112
 113 static struct regs_info regs_info =
 114   {
 115     NULL, /* regset_bitmap */
 116     &cris_usrregs_info,
 117   };
 118
 119 static const struct regs_info *
 120 cris_regs_info (void)
 121 {
 122   return &regs_info;
 123 }
 124
 125 struct linux_target_ops the_low_target = {
 126   cris_arch_setup,
 127   cris_regs_info,
 128   cris_cannot_fetch_register,
 129   cris_cannot_store_register,
 130   NULL, /* fetch_register */
 131   linux_get_pc_32bit,
 132   linux_set_pc_32bit,
 133   NULL, /* breakpoint_kind_from_pc */
 134   cris_sw_breakpoint_from_kind,
 135   NULL, /* get_next_pcs */
 136   0,
 137   cris_breakpoint_at,
 138 };
 139
 140 /* The linux target ops object.  */
 141
 142 linux_process_target *the_linux_target = &the_cris_target;
 143
 144 void
 145 initialize_low_arch (void)
 146 {
 147   init_registers_cris ();
 148 }