gdb/gdbserver/linux-cris-low.c

   1 /* GNU/Linux/CRIS specific low level interface, for the remote server for GDB.
   2    Copyright (C) 1995-2013 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 <sys/ptrace.h>
  22
  23 /* Defined in auto-generated file reg-cris.c.  */
  24 void init_registers_cris (void);
  25
  26 /* CRISv10 */
  27 #define cris_num_regs 32
  28
  29 /* Locations need to match <include/asm/arch/ptrace.h>.  */
  30 static int cris_regmap[] = {
  31   15*4, 14*4, 13*4, 12*4,
  32   11*4, 10*4, 9*4, 8*4,
  33   7*4, 6*4, 5*4, 4*4,
  34   3*4, 2*4, 23*4, 19*4,
  35
  36   -1, -1, -1, -1,
  37   -1, 17*4, -1, 16*4,
  38   -1, -1, -1, 18*4,
  39   -1, 17*4, -1, -1
  40
  41 };
  42
  43 static int
  44 cris_cannot_store_register (int regno)
  45 {
  46   if (cris_regmap[regno] == -1)
  47     return 1;
  48
  49   return (regno >= cris_num_regs);
  50 }
  51
  52 static int
  53 cris_cannot_fetch_register (int regno)
  54 {
  55   if (cris_regmap[regno] == -1)
  56     return 1;
  57
  58   return (regno >= cris_num_regs);
  59 }
  60
  61 extern int debug_threads;
  62
  63 static CORE_ADDR
  64 cris_get_pc (struct regcache *regcache, void)
  65 {
  66   unsigned long pc;
  67   collect_register_by_name (regcache, "pc", &pc);
  68   if (debug_threads)
  69     fprintf (stderr, "stop pc is %08lx\n", pc);
  70   return pc;
  71 }
  72
  73 static void
  74 cris_set_pc (struct regcache *regcache, CORE_ADDR pc)
  75 {
  76   unsigned long newpc = pc;
  77   supply_register_by_name (regcache, "pc", &newpc);
  78 }
  79
  80 static const unsigned short cris_breakpoint = 0xe938;
  81 #define cris_breakpoint_len 2
  82
  83 static int
  84 cris_breakpoint_at (CORE_ADDR where)
  85 {
  86   unsigned short insn;
  87
  88   (*the_target->read_memory) (where, (unsigned char *) &insn,
  89                               cris_breakpoint_len);
  90   if (insn == cris_breakpoint)
  91     return 1;
  92
  93   /* If necessary, recognize more trap instructions here.  GDB only uses the
  94      one.  */
  95   return 0;
  96 }
  97
  98 /* We only place breakpoints in empty marker functions, and thread locking
  99    is outside of the function.  So rather than importing software single-step,
 100    we can just run until exit.  */
 101 static CORE_ADDR
 102 cris_reinsert_addr (void)
 103 {
 104   struct regcache *regcache = get_thread_regcache (current_inferior, 1);
 105   unsigned long pc;
 106   collect_register_by_name (regcache, "srp", &pc);
 107   return pc;
 108 }
 109
 110 struct linux_target_ops the_low_target = {
 111   init_registers_cris,
 112   cris_num_regs,
 113   cris_regmap,
 114   NULL,
 115   cris_cannot_fetch_register,
 116   cris_cannot_store_register,
 117   NULL, /* fetch_register */
 118   cris_get_pc,
 119   cris_set_pc,
 120   (const unsigned char *) &cris_breakpoint,
 121   cris_breakpoint_len,
 122   cris_reinsert_addr,
 123   0,
 124   cris_breakpoint_at,
 125   0,
 126   0,
 127   0,
 128   0,
 129 };