sim/i960/traps.c

   1 /* i960 exception, interrupt, and trap (EIT) support
   2    Copyright (C) 1998, 1999 Free Software Foundation, Inc.
   3    Contributed by Cygnus Solutions.
   4
   5 This file is part of GDB, the GNU debugger.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License along
  18 with this program; if not, write to the Free Software Foundation, Inc.,
  19 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 #include "sim-main.h"
  22 #include "targ-vals.h"
  23
  24 /* The semantic code invokes this for illegal (unrecognized) instructions.  */
  25
  26 SEM_PC
  27 sim_engine_invalid_insn (SIM_CPU *current_cpu, IADDR cia, SEM_PC vpc)
  28 {
  29   SIM_DESC sd = CPU_STATE (current_cpu);
  30
  31 #if 0
  32   if (STATE_ENVIRONMENT (sd) == OPERATING_ENVIRONMENT)
  33     {
  34       h_bsm_set (current_cpu, h_sm_get (current_cpu));
  35       h_bie_set (current_cpu, h_ie_get (current_cpu));
  36       h_bcond_set (current_cpu, h_cond_get (current_cpu));
  37       /* sm not changed */
  38       h_ie_set (current_cpu, 0);
  39       h_cond_set (current_cpu, 0);
  40
  41       h_bpc_set (current_cpu, cia);
  42
  43       sim_engine_restart (CPU_STATE (current_cpu), current_cpu, NULL,
  44                           EIT_RSVD_INSN_ADDR);
  45     }
  46   else
  47 #endif
  48     sim_engine_halt (sd, current_cpu, NULL, cia, sim_stopped, SIM_SIGILL);
  49   return vpc;
  50 }
  51
  52 /* Process an address exception.  */
  53
  54 void
  55 i960_core_signal (SIM_DESC sd, SIM_CPU *current_cpu, sim_cia cia,
  56                   unsigned int map, int nr_bytes, address_word addr,
  57                   transfer_type transfer, sim_core_signals sig)
  58 {
  59 #if 0
  60   if (STATE_ENVIRONMENT (sd) == OPERATING_ENVIRONMENT)
  61     {
  62       h_bsm_set (current_cpu, h_sm_get (current_cpu));
  63       h_bie_set (current_cpu, h_ie_get (current_cpu));
  64       h_bcond_set (current_cpu, h_cond_get (current_cpu));
  65       /* sm not changed */
  66       h_ie_set (current_cpu, 0);
  67       h_cond_set (current_cpu, 0);
  68
  69       h_bpc_set (current_cpu, cia);
  70
  71       sim_engine_restart (CPU_STATE (current_cpu), current_cpu, NULL,
  72                           EIT_ADDR_EXCP_ADDR);
  73     }
  74   else
  75 #endif
  76     sim_core_signal (sd, current_cpu, cia, map, nr_bytes, addr,
  77                      transfer, sig);
  78 }
  79 \f
  80 /* Read/write functions for system call interface.  */
  81
  82 static int
  83 syscall_read_mem (host_callback *cb, struct cb_syscall *sc,
  84                   unsigned long taddr, char *buf, int bytes)
  85 {
  86   SIM_DESC sd = (SIM_DESC) sc->p1;
  87   SIM_CPU *cpu = (SIM_CPU *) sc->p2;
  88
  89   return sim_core_read_buffer (sd, cpu, read_map, buf, taddr, bytes);
  90 }
  91
  92 static int
  93 syscall_write_mem (host_callback *cb, struct cb_syscall *sc,
  94                    unsigned long taddr, const char *buf, int bytes)
  95 {
  96   SIM_DESC sd = (SIM_DESC) sc->p1;
  97   SIM_CPU *cpu = (SIM_CPU *) sc->p2;
  98
  99   return sim_core_write_buffer (sd, cpu, write_map, buf, taddr, bytes);
 100 }
 101
 102 /* Trap support.
 103    The result is the pc address to continue at.
 104    Preprocessing like saving the various registers has already been done.  */
 105
 106 USI
 107 i960_trap (SIM_CPU *current_cpu, PCADDR pc, int num)
 108 {
 109   SIM_DESC sd = CPU_STATE (current_cpu);
 110   host_callback *cb = STATE_CALLBACK (sd);
 111
 112 #ifdef SIM_HAVE_BREAKPOINTS
 113   /* Check for breakpoints "owned" by the simulator first, regardless
 114      of --environment.  */
 115   if (num == TRAP_BREAKPOINT)
 116     {
 117       /* First try sim-break.c.  If it's a breakpoint the simulator "owns"
 118          it doesn't return.  Otherwise it returns and let's us try.  */
 119       sim_handle_breakpoint (sd, current_cpu, pc);
 120       /* Fall through.  */
 121     }
 122 #endif
 123
 124 #if 0
 125   /* ??? wilson, don't know what this does.  */
 126   if (STATE_ENVIRONMENT (sd) == OPERATING_ENVIRONMENT)
 127     {
 128       /* The new pc is the trap vector entry.
 129          We assume there's a branch there to some handler.  */
 130       USI new_pc = EIT_TRAP_BASE_ADDR + num * 4;
 131       return new_pc;
 132     }
 133 #endif
 134
 135   switch (num)
 136     {
 137     default:
 138     case TRAP_SYSCALL :
 139       {
 140         CB_SYSCALL s;
 141
 142         CB_SYSCALL_INIT (&s);
 143         s.func = num;
 144         s.arg1 = a_i960_h_gr_get (current_cpu, 16);
 145         s.arg2 = a_i960_h_gr_get (current_cpu, 17);
 146         s.arg3 = a_i960_h_gr_get (current_cpu, 18);
 147
 148         if (s.func == TARGET_SYS_exit)
 149           {
 150             sim_engine_halt (sd, current_cpu, NULL, pc, sim_exited, s.arg1);
 151           }
 152
 153         s.p1 = (PTR) sd;
 154         s.p2 = (PTR) current_cpu;
 155         s.read_mem = syscall_read_mem;
 156         s.write_mem = syscall_write_mem;
 157         cb_syscall (cb, &s);
 158         /* ??? This stuff is probably wrong, but libgloss doesn't look at
 159            these values, so it shouldn't matter.  */
 160         a_i960_h_gr_set (current_cpu, 18, s.errcode);
 161         a_i960_h_gr_set (current_cpu, 16, s.result);
 162         a_i960_h_gr_set (current_cpu, 17, s.result2);
 163         break;
 164       }
 165
 166     case TRAP_BREAKPOINT:
 167       sim_engine_halt (sd, current_cpu, NULL, NULL_CIA,
 168                        sim_stopped, SIM_SIGTRAP);
 169       break;
 170
 171 #if 0
 172       /* ??? wilson, don't know what this does.  */
 173     default :
 174       {
 175         USI new_pc = EIT_TRAP_BASE_ADDR + num * 4;
 176         return new_pc;
 177       }
 178 #endif
 179     }
 180
 181   /* Fake an "rte" insn.  */
 182   /* FIXME: Should duplicate all of rte processing.  */
 183   return (pc & -4) + 4;
 184 }
 185
 186 /* Breakpoint support.
 187    The result is the pc address to continue at.  */
 188 /* ??? This is an editted copy of the above.  */
 189
 190 USI
 191 i960_breakpoint (SIM_CPU *current_cpu, PCADDR pc)
 192 {
 193   SIM_DESC sd = CPU_STATE (current_cpu);
 194   host_callback *cb = STATE_CALLBACK (sd);
 195
 196 #ifdef SIM_HAVE_BREAKPOINTS
 197   /* Check for breakpoints "owned" by the simulator first, regardless
 198      of --environment.  */
 199   if (num == TRAP_BREAKPOINT)
 200     {
 201       /* First try sim-break.c.  If it's a breakpoint the simulator "owns"
 202          it doesn't return.  Otherwise it returns and let's us try.  */
 203       sim_handle_breakpoint (sd, current_cpu, pc);
 204       /* Fall through.  */
 205     }
 206 #endif
 207
 208   sim_engine_halt (sd, current_cpu, NULL, NULL_CIA,
 209                    sim_stopped, SIM_SIGTRAP);
 210
 211   /* Fake an "rte" insn.  */
 212   /* FIXME: Should duplicate all of rte processing.  */
 213   return (pc & -4) + 4;
 214 }