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/* except.c -- Simulation of OR1K exceptions

   Copyright (C) 1999 Damjan Lampret, lampret@opencores.org

This file is part of OpenRISC 1000 Architectural Simulator.

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include "abstract.h"

#include "except.h"

#include "sprs.h"

extern int cont_run;

extern struct iqueue_entry iqueue[20];

extern unsigned long pc;

extern unsigned long pcnext;

extern unsigned long pc_phy;

extern struct iqueue_entry iqueue[];

extern int delay_insn;

int cycle_delay = 0;  /* Added by CZ 27/05/01 */

/* Handle OR1K exceptions. */

void except_handle(int except, unsigned long ea)

{

        unsigned long pc_saved;

        printf("Exception 0x%x (%s): ", except, EXCEPT_NAME(except));

        printf("Iqueue[0].insn_addr: 0x%x  Eff ADDR: 0x%x\n",  iqueue[0].insn_addr, ea);

        printf("  pc: 0x%x  pcnext: 0x%x\n",  pc, pcnext);

#if ONLY_VIRTUAL_MACHINE

        printf("WARNING: No exception processing while ONLY_VIRTUAL_MACHINE is defined.\n");

        cont_run = 0;

#else

        if (delay_insn) {

                printf(" INFO: Exception during execution of delay slot insn.\n");

                pc -= 4;

        }

#if 0

        if ((pcnext != (pc + 4)) && (except != EXCEPT_ITLBMISS)) {      /* Always execute delay slot insn */

                printf("XXXXXXXXXXXXXX\n");

                fetch();                                                /* before starting with exception */

                decode(&iqueue[0]);                                      /* (itlbmiss is special case) */

                execute();

        }

#endif

        if (!(mfspr(SPR_SR) & SPR_SR_EXR)) {

                printf("ABORT: Exception occured while exception detection was disabled.\n");

                cont_run = 0;

                return;

        }

        pc_saved = pc & ~0x3;

        mtspr(SPR_EPCR_BASE, pc_saved);

        mtspr(SPR_EEAR_BASE, ea);

        mtspr(SPR_ESR_BASE, mfspr(SPR_SR));

        /* Address translation is always disabled when starting exception. */

        mtspr(SPR_SR, mfspr(SPR_SR) & ~(SPR_SR_DME));

        mtspr(SPR_SR, mfspr(SPR_SR) & ~(SPR_SR_IME));

        mtspr(SPR_SR, mfspr(SPR_SR) | SPR_SR_SUPV);     /* SUPV mode */

        mtspr(SPR_SR, mfspr(SPR_SR) & ~SPR_SR_EXR);     /* Disable except. */

        pc = (unsigned long)except;

        /* MM: We do pc update after the execute (in the simulator), so we

           decrease it by 4 so that next instruction points to first exception

           instruction. */

        if (except == EXCEPT_SYSCALL)

          pc -= 4;

        pcnext = pc+4;

        /* Added by CZ 27/05/01 */

        pc_phy = pc;

        cycle_delay = 7;  /* An exception stalls the CPU 7 clock cycles */

#endif

}