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 /* Defined in auto-generated file reg-cris.c.  */
  24 void init_registers_cris (void);
  25 extern const struct target_desc *tdesc_cris;
  26
  27 /* CRISv10 */
  28 #define cris_num_regs 32
  29
  30 /* Locations need to match <include/asm/arch/ptrace.h>.  */
  31 static int cris_regmap[] = {
  32   15*4, 14*4, 13*4, 12*4,
  33   11*4, 10*4, 9*4, 8*4,
  34   7*4, 6*4, 5*4, 4*4,
  35   3*4, 2*4, 23*4, 19*4,
  36
  37   -1, -1, -1, -1,
  38   -1, 17*4, -1, 16*4,
  39   -1, -1, -1, 18*4,
  40   -1, 17*4, -1, -1
  41
  42 };
  43
  44 static int
  45 cris_cannot_store_register (int regno)
  46 {
  47   if (cris_regmap[regno] == -1)
  48     return 1;
  49
  50   return (regno >= cris_num_regs);
  51 }
  52
  53 static int
  54 cris_cannot_fetch_register (int regno)
  55 {
  56   if (cris_regmap[regno] == -1)
  57     return 1;
  58
  59   return (regno >= cris_num_regs);
  60 }
  61
  62 static const unsigned short cris_breakpoint = 0xe938;
  63 #define cris_breakpoint_len 2
  64
  65 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
  66
  67 static const gdb_byte *
  68 cris_sw_breakpoint_from_kind (int kind, int *size)
  69 {
  70   *size = cris_breakpoint_len;
  71   return (const gdb_byte *) &cris_breakpoint;
  72 }
  73
  74 static int
  75 cris_breakpoint_at (CORE_ADDR where)
  76 {
  77   unsigned short insn;
  78
  79   the_target->pt->read_memory (where, (unsigned char *) &insn,
  80                                cris_breakpoint_len);
  81   if (insn == cris_breakpoint)
  82     return 1;
  83
  84   /* If necessary, recognize more trap instructions here.  GDB only uses the
  85      one.  */
  86   return 0;
  87 }
  88
  89 static void
  90 cris_arch_setup (void)
  91 {
  92   current_process ()->tdesc = tdesc_cris;
  93 }
  94
  95 static struct usrregs_info cris_usrregs_info =
  96   {
  97     cris_num_regs,
  98     cris_regmap,
  99   };
 100
 101 static struct regs_info regs_info =
 102   {
 103     NULL, /* regset_bitmap */
 104     &cris_usrregs_info,
 105   };
 106
 107 static const struct regs_info *
 108 cris_regs_info (void)
 109 {
 110   return &regs_info;
 111 }
 112
 113 struct linux_target_ops the_low_target = {
 114   cris_arch_setup,
 115   cris_regs_info,
 116   cris_cannot_fetch_register,
 117   cris_cannot_store_register,
 118   NULL, /* fetch_register */
 119   linux_get_pc_32bit,
 120   linux_set_pc_32bit,
 121   NULL, /* breakpoint_kind_from_pc */
 122   cris_sw_breakpoint_from_kind,
 123   NULL, /* get_next_pcs */
 124   0,
 125   cris_breakpoint_at,
 126 };
 127
 128 void
 129 initialize_low_arch (void)
 130 {
 131   init_registers_cris ();
 132 }