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 protected:
  30
  31   void low_arch_setup () override;
  32 };
  33
  34 /* The singleton target ops object.  */
  35
  36 static cris_target the_cris_target;
  37
  38 /* Defined in auto-generated file reg-cris.c.  */
  39 void init_registers_cris (void);
  40 extern const struct target_desc *tdesc_cris;
  41
  42 /* CRISv10 */
  43 #define cris_num_regs 32
  44
  45 /* Locations need to match <include/asm/arch/ptrace.h>.  */
  46 static int cris_regmap[] = {
  47   15*4, 14*4, 13*4, 12*4,
  48   11*4, 10*4, 9*4, 8*4,
  49   7*4, 6*4, 5*4, 4*4,
  50   3*4, 2*4, 23*4, 19*4,
  51
  52   -1, -1, -1, -1,
  53   -1, 17*4, -1, 16*4,
  54   -1, -1, -1, 18*4,
  55   -1, 17*4, -1, -1
  56
  57 };
  58
  59 static int
  60 cris_cannot_store_register (int regno)
  61 {
  62   if (cris_regmap[regno] == -1)
  63     return 1;
  64
  65   return (regno >= cris_num_regs);
  66 }
  67
  68 static int
  69 cris_cannot_fetch_register (int regno)
  70 {
  71   if (cris_regmap[regno] == -1)
  72     return 1;
  73
  74   return (regno >= cris_num_regs);
  75 }
  76
  77 static const unsigned short cris_breakpoint = 0xe938;
  78 #define cris_breakpoint_len 2
  79
  80 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
  81
  82 static const gdb_byte *
  83 cris_sw_breakpoint_from_kind (int kind, int *size)
  84 {
  85   *size = cris_breakpoint_len;
  86   return (const gdb_byte *) &cris_breakpoint;
  87 }
  88
  89 static int
  90 cris_breakpoint_at (CORE_ADDR where)
  91 {
  92   unsigned short insn;
  93
  94   the_target->read_memory (where, (unsigned char *) &insn,
  95                            cris_breakpoint_len);
  96   if (insn == cris_breakpoint)
  97     return 1;
  98
  99   /* If necessary, recognize more trap instructions here.  GDB only uses the
 100      one.  */
 101   return 0;
 102 }
 103
 104 void
 105 cris_target::low_arch_setup ()
 106 {
 107   current_process ()->tdesc = tdesc_cris;
 108 }
 109
 110 static struct usrregs_info cris_usrregs_info =
 111   {
 112     cris_num_regs,
 113     cris_regmap,
 114   };
 115
 116 static struct regs_info regs_info =
 117   {
 118     NULL, /* regset_bitmap */
 119     &cris_usrregs_info,
 120   };
 121
 122 static const struct regs_info *
 123 cris_regs_info (void)
 124 {
 125   return &regs_info;
 126 }
 127
 128 struct linux_target_ops the_low_target = {
 129   cris_regs_info,
 130   cris_cannot_fetch_register,
 131   cris_cannot_store_register,
 132   NULL, /* fetch_register */
 133   linux_get_pc_32bit,
 134   linux_set_pc_32bit,
 135   NULL, /* breakpoint_kind_from_pc */
 136   cris_sw_breakpoint_from_kind,
 137   NULL, /* get_next_pcs */
 138   0,
 139   cris_breakpoint_at,
 140 };
 141
 142 /* The linux target ops object.  */
 143
 144 linux_process_target *the_linux_target = &the_cris_target;
 145
 146 void
 147 initialize_low_arch (void)
 148 {
 149   init_registers_cris ();
 150 }