gdb/gdbserver/linux-cris-low.c

   1 /* GNU/Linux/CRIS specific low level interface, for the remote server for GDB.
   2    Copyright (C) 1995-2015 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 extern int debug_threads;
  63
  64 static CORE_ADDR
  65 cris_get_pc (struct regcache *regcache)
  66 {
  67   unsigned long pc;
  68   collect_register_by_name (regcache, "pc", &pc);
  69   if (debug_threads)
  70     debug_printf ("stop pc is %08lx\n", pc);
  71   return pc;
  72 }
  73
  74 static void
  75 cris_set_pc (struct regcache *regcache, CORE_ADDR pc)
  76 {
  77   unsigned long newpc = pc;
  78   supply_register_by_name (regcache, "pc", &newpc);
  79 }
  80
  81 static const unsigned short cris_breakpoint = 0xe938;
  82 #define cris_breakpoint_len 2
  83
  84 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
  85
  86 static const gdb_byte *
  87 cris_sw_breakpoint_from_kind (int kind, int *size)
  88 {
  89   *size = cris_breakpoint_len;
  90   return (const gdb_byte *) &cris_breakpoint;
  91 }
  92
  93 static int
  94 cris_breakpoint_at (CORE_ADDR where)
  95 {
  96   unsigned short insn;
  97
  98   (*the_target->read_memory) (where, (unsigned char *) &insn,
  99                               cris_breakpoint_len);
 100   if (insn == cris_breakpoint)
 101     return 1;
 102
 103   /* If necessary, recognize more trap instructions here.  GDB only uses the
 104      one.  */
 105   return 0;
 106 }
 107
 108 /* We only place breakpoints in empty marker functions, and thread locking
 109    is outside of the function.  So rather than importing software single-step,
 110    we can just run until exit.  */
 111 static CORE_ADDR
 112 cris_reinsert_addr (void)
 113 {
 114   struct regcache *regcache = get_thread_regcache (current_thread, 1);
 115   unsigned long pc;
 116   collect_register_by_name (regcache, "srp", &pc);
 117   return pc;
 118 }
 119
 120 static void
 121 cris_arch_setup (void)
 122 {
 123   current_process ()->tdesc = tdesc_cris;
 124 }
 125
 126 static struct usrregs_info cris_usrregs_info =
 127   {
 128     cris_num_regs,
 129     cris_regmap,
 130   };
 131
 132 static struct regs_info regs_info =
 133   {
 134     NULL, /* regset_bitmap */
 135     &cris_usrregs_info,
 136   };
 137
 138 static const struct regs_info *
 139 cris_regs_info (void)
 140 {
 141   return &regs_info;
 142 }
 143
 144 struct linux_target_ops the_low_target = {
 145   cris_arch_setup,
 146   cris_regs_info,
 147   cris_cannot_fetch_register,
 148   cris_cannot_store_register,
 149   NULL, /* fetch_register */
 150   cris_get_pc,
 151   cris_set_pc,
 152   NULL, /* breakpoint_kind_from_pc */
 153   cris_sw_breakpoint_from_kind,
 154   cris_reinsert_addr,
 155   0,
 156   cris_breakpoint_at,
 157   0,
 158   0,
 159   0,
 160   0,
 161 };
 162
 163 void
 164 initialize_low_arch (void)
 165 {
 166   init_registers_cris ();
 167 }