Archipelago » qemu

#include "hw.h"

#include "mips.h"

#include "qemu-timer.h"

#define TIMER_FREQ        100 * 1000 * 1000

void cpu_mips_irqctrl_init (void)

{

}

/* XXX: do not use a global */

uint32_t cpu_mips_get_random (CPUState *env)

{

    static uint32_t seed = 0;

    uint32_t idx;

    seed = seed * 314159 + 1;

    idx = (seed >> 16) % (env->tlb->nb_tlb - env->CP0_Wired) + env->CP0_Wired;

    return idx;

}

/* MIPS R4K timer */

uint32_t cpu_mips_get_count (CPUState *env)

{

    if (env->CP0_Cause & (1 << CP0Ca_DC))

        return env->CP0_Count;

    else

        return env->CP0_Count +

            (uint32_t)muldiv64(qemu_get_clock(vm_clock),

                               TIMER_FREQ, ticks_per_sec);

}

static void cpu_mips_timer_update(CPUState *env)

{

    uint64_t now, next;

    uint32_t wait;

    now = qemu_get_clock(vm_clock);

    wait = env->CP0_Compare - env->CP0_Count -

            (uint32_t)muldiv64(now, TIMER_FREQ, ticks_per_sec);

    next = now + muldiv64(wait, ticks_per_sec, TIMER_FREQ);

    qemu_mod_timer(env->timer, next);

}

void cpu_mips_store_count (CPUState *env, uint32_t count)

{

    if (env->CP0_Cause & (1 << CP0Ca_DC))

        env->CP0_Count = count;

    else {

        /* Store new count register */

        env->CP0_Count =

            count - (uint32_t)muldiv64(qemu_get_clock(vm_clock),

                                       TIMER_FREQ, ticks_per_sec);

        /* Update timer timer */

        cpu_mips_timer_update(env);

    }

}

void cpu_mips_store_compare (CPUState *env, uint32_t value)

{

    env->CP0_Compare = value;

    if (!(env->CP0_Cause & (1 << CP0Ca_DC)))

        cpu_mips_timer_update(env);

    if (env->insn_flags & ISA_MIPS32R2)

        env->CP0_Cause &= ~(1 << CP0Ca_TI);

    qemu_irq_lower(env->irq[(env->CP0_IntCtl >> CP0IntCtl_IPTI) & 0x7]);

}

void cpu_mips_start_count(CPUState *env)

{

    cpu_mips_store_count(env, env->CP0_Count);

}

void cpu_mips_stop_count(CPUState *env)

{

    /* Store the current value */

    env->CP0_Count += (uint32_t)muldiv64(qemu_get_clock(vm_clock),

                                         TIMER_FREQ, ticks_per_sec);

}

static void mips_timer_cb (void *opaque)

{

    CPUState *env;

    env = opaque;

#if 0

    if (logfile) {

        fprintf(logfile, "%s\n", __func__);

    }

#endif

    if (env->CP0_Cause & (1 << CP0Ca_DC))

        return;

    cpu_mips_timer_update(env);

    if (env->insn_flags & ISA_MIPS32R2)

        env->CP0_Cause |= 1 << CP0Ca_TI;

    qemu_irq_raise(env->irq[(env->CP0_IntCtl >> CP0IntCtl_IPTI) & 0x7]);

}

void cpu_mips_clock_init (CPUState *env)

{

    env->timer = qemu_new_timer(vm_clock, &mips_timer_cb, env);

    env->CP0_Compare = 0;

    cpu_mips_store_count(env, 1);

}