pic.c File Reference

#include "ntvdm.h"
#include <debug.h>
#include "emulator.h"
#include "pic.h"
#include "io.h"

Include dependency graph for pic.c:

Go to the source code of this file.

Classes
struct	_PIC

Macros
#define	NDEBUG

Typedefs
typedef struct _PIC	PIC
typedef struct _PIC *	PPIC

Functions
static BYTE WINAPI	PicReadCommand (USHORT Port)
static VOID WINAPI	PicWriteCommand (USHORT Port, BYTE Data)
static BYTE WINAPI	PicReadData (USHORT Port)
static VOID WINAPI	PicWriteData (USHORT Port, BYTE Data)
VOID	PicInterruptRequest (BYTE Number)
BYTE	PicGetInterrupt (VOID)
VOID	PicInitialize (VOID)
VOID WINAPI	call_ica_hw_interrupt (INT ms, BYTE line, INT count)
WORD WINAPI	VDDReserveIrqLine (IN HANDLE hVdd, IN WORD IrqLine)
BOOL WINAPI	VDDReleaseIrqLine (IN HANDLE hVdd, IN WORD IrqLine)

Variables
static PIC	MasterPic
static PIC	SlavePic

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 14 of file pic.c.

Typedef Documentation

PIC

typedef struct _PIC PIC

PPIC

typedef struct _PIC * PPIC

Function Documentation

call_ica_hw_interrupt()

VOID WINAPI call_ica_hw_interrupt	(	INT	ms,
		BYTE	line,
		INT	count
	)

Definition at line 308 of file pic.c.

{
    BYTE InterruptNumber = line;

    /* Check for PIC validity */
    if (ms != ICA_MASTER && ms != ICA_SLAVE) return;

    /*
     * Adjust the interrupt request number according to the parameters,
     * by adding an offset == 8 to the interrupt number.
     *
     * Indeed VDDs calling this function usually subtracts 8 so that they give:
     *
     *      ms     |  line  | corresponding interrupt number
     * ------------+--------+--------------------------------
     *  ICA_MASTER | 0 -- 7 |            0 -- 7
     *  ICA_SLAVE  | 0 -- 7 |            8 -- 15
     *
     * and PicInterruptRequest subtracts again 8 to the interrupt number
     * if it is greater or equal than 8 (so that it determines which PIC
     * to use via the interrupt number).
     */
    if (ms == ICA_SLAVE) InterruptNumber += 8;

    /* Send the specified number of interrupt requests */
    while (count-- > 0)
    {
        PicInterruptRequest(InterruptNumber);
        /*
         * FIXME: We should now restart 16-bit emulation and wait for its termination:
         *
         * "When the VDD calls VDDSimulateInterrupt, the address pointed to by
         * the interrupt vector starts running in 16-bit mode. For an asynchronous
         * interrupt, the VDD should create another thread and call VDDSimulateInterrupt
         * from that thread."
         */
    }
}

PicGetInterrupt()

BYTE PicGetInterrupt

(

VOID

)

Definition at line 244 of file pic.c.

{
    UINT i;

    /* Search the master PIC interrupts by priority */
    for (i = 0; i < 8; i++)
    {
        if (MasterPic.IntRequestRegister & (1 << i))
        {
            /* Clear the IRR flag */
            MasterPic.IntRequestRegister &= ~(1 << i);

            /* Set the ISR flag, unless AEOI is enabled */
            if (!MasterPic.AutoEoi) MasterPic.InServiceRegister |= (1 << i);

            /* Return the interrupt number */
            return MasterPic.IntOffset + i;
        }
    }

    /* Search the slave PIC interrupts by priority */
    for (i = 0; i < 8; i++)
    {
        if (SlavePic.IntRequestRegister & (1 << i))
        {
            /* Clear the IRR flag */
            SlavePic.IntRequestRegister &= ~(1 << i);

            if ((i == 1) && SlavePic.CascadeRegisterSet)
            {
                /* This interrupt is routed to the master PIC */
                return MasterPic.IntOffset + SlavePic.CascadeRegister;
            }
            else
            {
                /* Set the ISR flag, unless AEOI is enabled */
                if (!SlavePic.AutoEoi) SlavePic.InServiceRegister |= (1 << i);

                /* Return the interrupt number */
                return SlavePic.IntOffset + i;
            }
        }
    }

    /* Spurious interrupt */
    if (MasterPic.InServiceRegister & (1 << 2))
        return SlavePic.IntOffset + 7;
    else
        return MasterPic.IntOffset + 7;
}

Referenced by EmulatorIntAcknowledge().

PicInitialize()

VOID PicInitialize

(

VOID

)

Definition at line 295 of file pic.c.

{
    /* Register the I/O Ports */
    RegisterIoPort(PIC_MASTER_CMD , PicReadCommand, PicWriteCommand);
    RegisterIoPort(PIC_SLAVE_CMD  , PicReadCommand, PicWriteCommand);
    RegisterIoPort(PIC_MASTER_DATA, PicReadData   , PicWriteData   );
    RegisterIoPort(PIC_SLAVE_DATA , PicReadData   , PicWriteData   );
}

Referenced by EmulatorInitialize().

PicInterruptRequest()

VOID PicInterruptRequest

(

BYTE

Number

)

Definition at line 192 of file pic.c.

{
    BYTE i;

    if (/* Number >= 0 && */ Number < 8)
    {
        /* Check if any of the higher-priority interrupts are busy */
        for (i = 0; i <= Number; i++)
        {
            if (MasterPic.InServiceRegister & (1 << Number)) return;
        }

        /* Check if the interrupt is masked */
        if (MasterPic.MaskRegister & (1 << Number)) return;

        /* Set the appropriate bit in the IRR and interrupt the CPU */
        MasterPic.IntRequestRegister |= 1 << Number;
        EmulatorInterruptSignal();
    }
    else if (Number >= 8 && Number < 16)
    {
        Number -= 8;

        /*
         * The slave PIC is connected to IRQ 2, always! If the master PIC
         * was misconfigured, don't do anything.
         */
        if (!(MasterPic.CascadeRegister & (1 << 2))
            || SlavePic.CascadeRegister != 2)
        {
            return;
        }

        /* Check if any of the higher-priority interrupts are busy */
        if (MasterPic.InServiceRegister != 0) return;
        for (i = 0; i <= Number; i++)
        {
            if (SlavePic.InServiceRegister & (1 << Number)) return;
        }

        /* Check if the interrupt is masked */
        if (SlavePic.MaskRegister & (1 << Number)) return;

        /* Set the IRQ 2 bit in the master ISR */
        if (!MasterPic.AutoEoi) MasterPic.InServiceRegister |= (1 << 2);

        /* Set the appropriate bit in the IRR and interrupt the CPU */
        SlavePic.IntRequestRegister |= 1 << Number;
        EmulatorInterruptSignal();
    }
}

Referenced by call_ica_hw_interrupt(), EmulatorFpu(), GeneratePS2Irq(), PitChan0Out(), RtcPeriodicTick(), and RtcTimeUpdate().

PicReadCommand()

static BYTE WINAPI PicReadCommand ( USHORT  Port )

static

Definition at line 43 of file pic.c.

{
    PPIC Pic;

    /* Which PIC are we accessing? */
    if (Port == PIC_MASTER_CMD)
        Pic = &MasterPic;
    else // if (Port == PIC_SLAVE_CMD)
        Pic = &SlavePic;

    if (Pic->ReadIsr)
    {
        /* Read the in-service register */
        Pic->ReadIsr = FALSE;
        return Pic->InServiceRegister;
    }
    else
    {
        /* Read the interrupt request register */
        return Pic->IntRequestRegister;
    }
}

Referenced by PicInitialize().

PicReadData()

static BYTE WINAPI PicReadData ( USHORT  Port )

static

Definition at line 120 of file pic.c.

{
    /* Read the mask register */
    if (Port == PIC_MASTER_DATA)
        return MasterPic.MaskRegister;
    else // if (Port == PIC_SLAVE_DATA)
        return SlavePic.MaskRegister;
}

Referenced by PicInitialize().

PicWriteCommand()

static VOID WINAPI PicWriteCommand ( USHORT  Port, BYTE  Data  )

static

Definition at line 66 of file pic.c.

{
    PPIC Pic;

    /* Which PIC are we accessing? */
    if (Port == PIC_MASTER_CMD)
        Pic = &MasterPic;
    else // if (Port == PIC_SLAVE_CMD)
        Pic = &SlavePic;

    if (Data & PIC_ICW1)
    {
        /* Start initialization */
        Pic->Initialization = TRUE;
        Pic->IntOffset = 0xFF;
        Pic->CascadeRegisterSet = FALSE;
        Pic->ConfigRegister = Data;
        return;
    }

    if (Data & PIC_OCW3)
    {
        /* This is an OCR3 */
        if (Data == PIC_OCW3_READ_ISR)
        {
            /* Return the ISR on next read from command port */
            Pic->ReadIsr = TRUE;
        }

        return;
    }

    /* This is an OCW2 */
    if (Data & PIC_OCW2_EOI)
    {
        if (Data & PIC_OCW2_SL)
        {
            /* If the SL bit is set, clear a specific IRQ */
            Pic->InServiceRegister &= ~(1 << (Data & PIC_OCW2_NUM_MASK));
        }
        else
        {
            /* Otherwise, clear all of them */
            Pic->InServiceRegister = 0;
        }

        if (MasterPic.IntRequestRegister || SlavePic.IntRequestRegister)
        {
            /* Signal the next IRQ */
            EmulatorInterruptSignal();
        }
    }
}

Referenced by PicInitialize().

PicWriteData()

static VOID WINAPI PicWriteData ( USHORT  Port, BYTE  Data  )

static

Definition at line 129 of file pic.c.

{
    PPIC Pic;

    /* Which PIC are we accessing? */
    if (Port == PIC_MASTER_DATA)
        Pic = &MasterPic;
    else // if (Port == PIC_SLAVE_DATA)
        Pic = &SlavePic;

    /* Is the PIC ready? */
    if (!Pic->Initialization)
    {
        /* Yes, this is an OCW1 */
        Pic->MaskRegister = Data;
        return;
    }

    /* Has the interrupt offset been set? */
    if (Pic->IntOffset == 0xFF)
    {
        /* This is an ICW2, set the offset (last three bits always zero) */
        Pic->IntOffset = Data & 0xF8;

        /* Check if we are in single mode and don't need an ICW4 */
        if ((Pic->ConfigRegister & PIC_ICW1_SINGLE)
            && !(Pic->ConfigRegister & PIC_ICW1_ICW4))
        {
            /* Yes, done initializing */
            Pic->Initialization = FALSE;
        }
        return;
    }

    /* Check if we are in cascade mode and the cascade register was not set */
    if (!(Pic->ConfigRegister & PIC_ICW1_SINGLE) && !Pic->CascadeRegisterSet)
    {
        /* This is an ICW3 */
        Pic->CascadeRegister    = Data;
        Pic->CascadeRegisterSet = TRUE;

        /* Check if we need an ICW4 */
        if (!(Pic->ConfigRegister & PIC_ICW1_ICW4))
        {
            /* No, done initializing */
            Pic->Initialization = FALSE;
        }
        return;
    }

    /* This must be an ICW4, we will ignore the 8086 bit (assume always set) */
    if (Data & PIC_ICW4_AEOI)
    {
        /* Use automatic end-of-interrupt */
        Pic->AutoEoi = TRUE;
    }

    /* Done initializing */
    Pic->Initialization = FALSE;
}

Referenced by PicInitialize().

VDDReleaseIrqLine()

BOOL WINAPI VDDReleaseIrqLine	(	IN HANDLE	hVdd,
		IN WORD	IrqLine
	)

Definition at line 361 of file pic.c.

{
    UNIMPLEMENTED;
    SetLastError(ERROR_INVALID_PARAMETER);
    return FALSE;
}

VDDReserveIrqLine()

WORD WINAPI VDDReserveIrqLine	(	IN HANDLE	hVdd,
		IN WORD	IrqLine
	)

Definition at line 351 of file pic.c.

{
    UNIMPLEMENTED;
    SetLastError(ERROR_INVALID_PARAMETER);
    return 0xFFFF;
}

Variable Documentation

MasterPic

PIC MasterPic

static

Definition at line 39 of file pic.c.

Referenced by PicGetInterrupt(), PicInterruptRequest(), PicReadCommand(), PicReadData(), PicWriteCommand(), and PicWriteData().

SlavePic

PIC SlavePic

static

Definition at line 39 of file pic.c.

Referenced by PicGetInterrupt(), PicInterruptRequest(), PicReadCommand(), PicReadData(), PicWriteCommand(), and PicWriteData().