main.cc

一个mips虚拟机非常好代码,使用C++来编写的,希望大家多学学,

// U4600 Programmable Interrupt Controller
// Matt Chapman <[e-mail]>

#include <stdio.h>
#include <string.h>
#include <assert.hh>
#include "pic.hh"


// Serialization information.

SerialType<U4600_PIC> U4600_PIC::type(
    "U4600_PIC",
    "U4600 Programmable Interrupt Controller"
);


// Runtime constructor.

U4600_PIC::U4600_PIC(const SimArgs& args)
    : Module(args), Device(8)
{
	if (args.length() > 2)
		throw Error("Too many arguments to \"sim::install U4600_PIC\".");
}


// Serialized constructor.

U4600_PIC::U4600_PIC(Checkpoint& cp)
    : Module(cp), Device(8)
{
}


// Module interface.

void
U4600_PIC::reset(bool warm)
{
	intr_pending = 0;
	intr_mask = 0xffff;
}


// Serialization interface.

void
U4600_PIC::checkpoint(Checkpoint& cp, bool parent) const
{
}


void
U4600_PIC::check_interrupts(void)
{
    if (intr_pending & ~intr_mask)
	bus->clock->deliver_interrupt(1);
    else
	bus->clock->clear_interrupt(1);
}


ClockValue
U4600_PIC::read(UInt64 addr, UInt64* buf, int size)
{
    unsigned int reg = addr & 3;
    switch (reg)
    {
	case 0: *buf = intr_pending; break;
	case 1: *buf = intr_pending >> 8; break;
	case 2: *buf = intr_mask; break;
	case 3: *buf = intr_mask >> 8; break;
    }
    return 0; // ignore latency
}


ClockValue
U4600_PIC::write(UInt64 addr, const UInt64* buf, int size)
{
    unsigned int reg = addr & 3;
    UInt16 val = *buf & 0xff;

    switch (reg)
    {
	case 0: intr_pending = val | (intr_pending & 0xff00); break;
	case 1: intr_pending = (val << 8) | (intr_pending & 0x00ff); break;
	case 2: intr_mask = val | (intr_mask & 0xff00); break;
	case 3: intr_mask = (val << 8) | (intr_mask & 0x00ff); break;
    }
    check_interrupts();
    return 0; // ignore latency
}

void
U4600_PIC::deliver_interrupt(unsigned int irq)
{
    intr_pending |= (1 << irq);
    check_interrupts();
}

void
U4600_PIC::clear_interrupt(unsigned int irq)
{
    intr_pending &= ~(1 << irq);
    check_interrupts();
}