/*
 *  qemu user cpu loop
 *
 *  Copyright (c) 2003-2008 Fabrice Bellard
 *
 *  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, see <http://www.gnu.org/licenses/>.
 */

#include "qemu/osdep.h"
#include "qemu.h"
#include "user-internals.h"
#include "user/cpu_loop.h"
#include "signal-common.h"

void cpu_loop(CPUSH4State *env)
{
    CPUState *cs = env_cpu(env);
    int trapnr, ret;

    while (1) {
        bool arch_interrupt = true;

        cpu_exec_start(cs);
        trapnr = cpu_exec(cs);
        cpu_exec_end(cs);
        qemu_process_cpu_events(cs);

        switch (trapnr) {
        case 0x160:
            env->pc += 2;
            ret = do_syscall(env,
                             env->gregs[3],
                             env->gregs[4],
                             env->gregs[5],
                             env->gregs[6],
                             env->gregs[7],
                             env->gregs[0],
                             env->gregs[1],
                             0, 0);
            if (ret == -QEMU_ERESTARTSYS) {
                env->pc -= 2;
            } else if (ret != -QEMU_ESIGRETURN && ret != -QEMU_ESETPC) {
                env->gregs[0] = ret;
            }
            break;
        case EXCP_INTERRUPT:
            /* just indicate that signals should be handled asap */
            break;
        case EXCP_DEBUG:
            force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
            break;
        case EXCP_ATOMIC:
            cpu_exec_step_atomic(cs);
            arch_interrupt = false;
            break;
        case 0x180:
            /* Illegal instruction */
            /* fallthrough */
        case 0x1a0:
            /* Illegal instruction in delay slot */
            force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
            break;
        default:
            fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
            cpu_dump_state(cs, stderr, 0);
            exit(EXIT_FAILURE);
        }
        process_pending_signals (env);

        /* Most of the traps imply an exception or interrupt, which
           implies an REI instruction has been executed.  Which means
           that LDST (aka LOK_ADDR) should be cleared.  But there are
           a few exceptions for traps internal to QEMU.  */
        if (arch_interrupt) {
            env->lock_addr = -1;
        }
    }
}

void init_main_thread(CPUState *cs, struct image_info *info)
{
    CPUArchState *env = cpu_env(cs);

    env->pc = info->entry;
    env->gregs[15] = info->start_stack;
}