241 lines
6.9 KiB
C
241 lines
6.9 KiB
C
/* Lattice Mico32 exception and system call support.
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Contributed by Jon Beniston <jon@beniston.com>
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Copyright (C) 2009-2022 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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/* This must come before any other includes. */
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#include "defs.h"
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#define WANT_CPU lm32bf
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#define WANT_CPU_LM32BF
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#include "sim-main.h"
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#include "sim-signal.h"
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#include "sim-syscall.h"
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#include "lm32-sim.h"
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#include "target-newlib-syscall.h"
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/* Handle invalid instructions. */
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SEM_PC
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sim_engine_invalid_insn (SIM_CPU * current_cpu, IADDR cia, SEM_PC pc)
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{
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SIM_DESC sd = CPU_STATE (current_cpu);
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sim_engine_halt (sd, current_cpu, NULL, cia, sim_stopped, SIM_SIGILL);
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return pc;
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}
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/* Handle divide instructions. */
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USI
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lm32bf_divu_insn (SIM_CPU * current_cpu, IADDR pc, USI r0, USI r1, USI r2)
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{
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SIM_DESC sd = CPU_STATE (current_cpu);
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host_callback *cb = STATE_CALLBACK (sd);
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/* Check for divide by zero */
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if (GET_H_GR (r1) == 0)
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{
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if (STATE_ENVIRONMENT (sd) != OPERATING_ENVIRONMENT)
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sim_engine_halt (sd, current_cpu, NULL, pc, sim_stopped, SIM_SIGFPE);
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else
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{
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/* Save PC in exception address register. */
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SET_H_GR (30, pc);
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/* Save and clear interrupt enable. */
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SET_H_CSR (LM32_CSR_IE, (GET_H_CSR (LM32_CSR_IE) & 1) << 1);
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/* Branch to divide by zero exception handler. */
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return GET_H_CSR (LM32_CSR_EBA) + LM32_EID_DIVIDE_BY_ZERO * 32;
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}
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}
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else
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{
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SET_H_GR (r2, (USI) GET_H_GR (r0) / (USI) GET_H_GR (r1));
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return pc + 4;
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}
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}
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USI
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lm32bf_modu_insn (SIM_CPU * current_cpu, IADDR pc, USI r0, USI r1, USI r2)
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{
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SIM_DESC sd = CPU_STATE (current_cpu);
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host_callback *cb = STATE_CALLBACK (sd);
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/* Check for divide by zero. */
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if (GET_H_GR (r1) == 0)
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{
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if (STATE_ENVIRONMENT (sd) != OPERATING_ENVIRONMENT)
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sim_engine_halt (sd, current_cpu, NULL, pc, sim_stopped, SIM_SIGFPE);
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else
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{
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/* Save PC in exception address register. */
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SET_H_GR (30, pc);
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/* Save and clear interrupt enable. */
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SET_H_CSR (LM32_CSR_IE, (GET_H_CSR (LM32_CSR_IE) & 1) << 1);
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/* Branch to divide by zero exception handler. */
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return GET_H_CSR (LM32_CSR_EBA) + LM32_EID_DIVIDE_BY_ZERO * 32;
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}
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}
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else
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{
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SET_H_GR (r2, (USI) GET_H_GR (r0) % (USI) GET_H_GR (r1));
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return pc + 4;
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}
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}
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/* Handle break instructions. */
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USI
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lm32bf_break_insn (SIM_CPU * current_cpu, IADDR pc)
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{
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SIM_DESC sd = CPU_STATE (current_cpu);
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host_callback *cb = STATE_CALLBACK (sd);
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/* Breakpoint. */
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if (STATE_ENVIRONMENT (sd) != OPERATING_ENVIRONMENT)
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{
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sim_engine_halt (sd, current_cpu, NULL, pc, sim_stopped, SIM_SIGTRAP);
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return pc;
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}
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else
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{
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/* Save PC in breakpoint address register. */
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SET_H_GR (31, pc);
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/* Save and clear interrupt enable. */
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SET_H_CSR (LM32_CSR_IE, (GET_H_CSR (LM32_CSR_IE) & 1) << 2);
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/* Branch to breakpoint exception handler. */
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return GET_H_CSR (LM32_CSR_DEBA) + LM32_EID_BREAKPOINT * 32;
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}
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}
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/* Handle scall instructions. */
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USI
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lm32bf_scall_insn (SIM_CPU * current_cpu, IADDR pc)
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{
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SIM_DESC sd = CPU_STATE (current_cpu);
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host_callback *cb = STATE_CALLBACK (sd);
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if ((STATE_ENVIRONMENT (sd) != OPERATING_ENVIRONMENT)
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|| (GET_H_GR (8) == TARGET_NEWLIB_SYS_exit))
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{
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/* Delegate system call to host O/S. */
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long result, result2;
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int errcode;
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/* Perform the system call. */
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sim_syscall_multi (current_cpu, GET_H_GR (8), GET_H_GR (1), GET_H_GR (2),
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GET_H_GR (3), GET_H_GR (4), &result, &result2,
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&errcode);
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/* Store the return value in the CPU's registers. */
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SET_H_GR (1, result);
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SET_H_GR (2, result2);
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SET_H_GR (3, errcode);
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/* Skip over scall instruction. */
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return pc + 4;
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}
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else
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{
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/* Save PC in exception address register. */
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SET_H_GR (30, pc);
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/* Save and clear interrupt enable */
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SET_H_CSR (LM32_CSR_IE, (GET_H_CSR (LM32_CSR_IE) & 1) << 1);
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/* Branch to system call exception handler. */
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return GET_H_CSR (LM32_CSR_EBA) + LM32_EID_SYSTEM_CALL * 32;
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}
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}
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/* Handle b instructions. */
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USI
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lm32bf_b_insn (SIM_CPU * current_cpu, USI r0, USI f_r0)
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{
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SIM_DESC sd = CPU_STATE (current_cpu);
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host_callback *cb = STATE_CALLBACK (sd);
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/* Restore interrupt enable. */
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if (f_r0 == 30)
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SET_H_CSR (LM32_CSR_IE, (GET_H_CSR (LM32_CSR_IE) & 2) >> 1);
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else if (f_r0 == 31)
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SET_H_CSR (LM32_CSR_IE, (GET_H_CSR (LM32_CSR_IE) & 4) >> 2);
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return r0;
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}
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/* Handle wcsr instructions. */
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void
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lm32bf_wcsr_insn (SIM_CPU * current_cpu, USI f_csr, USI r1)
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{
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SIM_DESC sd = CPU_STATE (current_cpu);
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host_callback *cb = STATE_CALLBACK (sd);
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/* Writing a 1 to IP CSR clears a bit, writing 0 has no effect. */
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if (f_csr == LM32_CSR_IP)
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SET_H_CSR (f_csr, GET_H_CSR (f_csr) & ~r1);
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else
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SET_H_CSR (f_csr, r1);
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}
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/* Handle signals. */
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void
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lm32_core_signal (SIM_DESC sd,
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sim_cpu * cpu,
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sim_cia cia,
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unsigned map,
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int nr_bytes,
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address_word addr,
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transfer_type transfer, sim_core_signals sig)
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{
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const char *copy = (transfer == read_transfer ? "read" : "write");
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address_word ip = CIA_ADDR (cia);
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SIM_CPU *current_cpu = cpu;
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switch (sig)
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{
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case sim_core_unmapped_signal:
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sim_io_eprintf (sd,
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"core: %d byte %s to unmapped address 0x%lx at 0x%lx\n",
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nr_bytes, copy, (unsigned long) addr,
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(unsigned long) ip);
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SET_H_GR (30, ip);
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/* Save and clear interrupt enable. */
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SET_H_CSR (LM32_CSR_IE, (GET_H_CSR (LM32_CSR_IE) & 1) << 1);
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CPU_PC_SET (cpu, GET_H_CSR (LM32_CSR_EBA) + LM32_EID_DATA_BUS_ERROR * 32);
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sim_engine_halt (sd, cpu, NULL, LM32_EID_DATA_BUS_ERROR * 32,
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sim_stopped, SIM_SIGSEGV);
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break;
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case sim_core_unaligned_signal:
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sim_io_eprintf (sd,
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"core: %d byte misaligned %s to address 0x%lx at 0x%lx\n",
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nr_bytes, copy, (unsigned long) addr,
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(unsigned long) ip);
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SET_H_GR (30, ip);
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/* Save and clear interrupt enable. */
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SET_H_CSR (LM32_CSR_IE, (GET_H_CSR (LM32_CSR_IE) & 1) << 1);
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CPU_PC_SET (cpu, GET_H_CSR (LM32_CSR_EBA) + LM32_EID_DATA_BUS_ERROR * 32);
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sim_engine_halt (sd, cpu, NULL, LM32_EID_DATA_BUS_ERROR * 32,
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sim_stopped, SIM_SIGBUS);
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break;
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default:
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sim_engine_abort (sd, cpu, cia,
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"sim_core_signal - internal error - bad switch");
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}
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}
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