Adding upstream version 7.0.14-dfsg.upstream/7.0.14-dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 1452 insertions, 0 deletions

diff --git a/src/VBox/ExtPacks/BusMouseSample/.scm-settings b/src/VBox/ExtPacks/BusMouseSample/.scm-settings
new file mode 100644
index 00000000..637f87d2
--- /dev/null
+++ b/src/VBox/ExtPacks/BusMouseSample/.scm-settings
@@ -0,0 +1,33 @@
+# $Id: .scm-settings $
+## @file
+# Source code massager settings for BusMouse sample.
+#
+
+#
+# Copyright (C) 2010-2023 Oracle and/or its affiliates.
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation
+# files (the "Software"), to deal in the Software without
+# restriction, including without limitation the rights to use,
+# copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following
+# conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+#
+
+# This directory contains sample code and are therefore under MIT license.
+--license-mit
+
diff --git a/src/VBox/ExtPacks/BusMouseSample/DevBusMouse.cpp b/src/VBox/ExtPacks/BusMouseSample/DevBusMouse.cpp
new file mode 100644
index 00000000..da480986
--- /dev/null
+++ b/src/VBox/ExtPacks/BusMouseSample/DevBusMouse.cpp
@@ -0,0 +1,901 @@
+/* $Id: DevBusMouse.cpp $ */
+/** @file
+ * BusMouse - Microsoft Bus (parallel) mouse controller device.
+ */
+
+/*
+ * Copyright (C) 2006-2023 Oracle and/or its affiliates.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#define LOG_GROUP LOG_GROUP_DEV_KBD
+#include <VBox/vmm/pdmdev.h>
+#ifndef IN_RING3
+# include <VBox/vmm/pdmapi.h>
+#endif
+#include <VBox/AssertGuest.h>
+#include <VBox/version.h>
+#include <iprt/assert.h>
+#include <iprt/uuid.h>
+
+/** @page pg_busmouse DevBusMouse - Microsoft Bus Mouse Emulation
+ *
+ * The Microsoft Bus Mouse was an early mouse sold by Microsoft, originally
+ * introduced in 1983. The mouse had a D-shaped 9-pin connector which plugged
+ * into a small ISA add-in board.
+ *
+ * The mouse itself was very simple (compared to a serial mouse) and most of the
+ * logic was located on the ISA board. Later, Microsoft sold an InPort mouse,
+ * which was also called a "bus mouse", but used a different interface.
+ *
+ * Microsoft part numbers for the Bus Mouse were 037-099 (100 ppi)
+ * and 037-199 (200 ppi).
+ *
+ * The Bus Mouse adapter included IRQ configuration jumpers (ref. MS article
+ * Q12230). The IRQ could be set to one of 2, 3, 4, 5. The typical setting
+ * would be IRQ 2 for a PC/XT and IRQ 5 for an AT compatible. Because IRQ 5
+ * may conflict with a SoundBlaster or a PCI device, this device defaults to
+ * IRQ 3. Note that IRQ 3 is also used by the COM 2 device, not often needed.
+ *
+ * The ISA adapter was built around an Intel 8255A compatible chip (ref.
+ * MS article Q46369). Once enabled, the adapter raises the configured IRQ
+ * 30 times per second; the rate is not configurable. The interrupts
+ * occur regardless of whether the mouse state has changed or not.
+ *
+ * To function properly, the 8255A must be programmed as follows:
+ *  - Port A: Input. Used to read motion deltas and button states.
+ *  - Port B: Output. Not used except for mouse detection.
+ *  - Port C: Split. Upper bits set as output, used for control purposes.
+ *                   Lower bits set as input, reflecting IRQ state.
+ *
+ * Detailed information was gleaned from Windows and OS/2 DDK mouse samples.
+ */
+
+
+/*********************************************************************************************************************************
+*   Defined Constants And Macros                                                                                                 *
+*********************************************************************************************************************************/
+/** The original bus mouse controller is fixed at I/O port 0x23C. */
+#define BMS_IO_BASE         0x23C
+#define BMS_IO_SIZE         4
+
+/** @name Offsets relative to the I/O base.
+ *@{ */
+#define BMS_PORT_DATA       0   /**< 8255 Port A. */
+#define BMS_PORT_SIG        1   /**< 8255 Port B. */
+#define BMS_PORT_CTRL       2   /**< 8255 Port C. */
+#define BMS_PORT_INIT       3   /**< 8255 Control Port. */
+/** @} */
+
+/** @name Port C bits (control port).
+ * @{  */
+#define BMS_CTL_INT_DIS     RT_BIT(4)   /**< Disable IRQ (else enabled). */
+#define BMS_CTL_SEL_HIGH    RT_BIT(5)   /**< Select hi nibble (else lo). */
+#define BMS_CTL_SEL_Y       RT_BIT(6)   /**< Select X to read (else Y). */
+#define BMS_CTL_HOLD        RT_BIT(7)   /**< Hold counter (else clear). */
+/** @} */
+
+/** @name Port A bits (data port).
+ * @{ */
+#define BMS_DATA_DELTA      0x0F        /**< Motion delta in lower nibble. */
+#define BMS_DATA_B3_UP      RT_BIT(5)   /**< Button 3 (right) is up. */
+#define BMS_DATA_B2_UP      RT_BIT(6)   /**< Button 2 (middle) is up. */
+#define BMS_DATA_B1_UP      RT_BIT(7)   /**< Button 1 (left) is up. */
+/** @} */
+
+/** Convert IRQ level (2/3/4/5) to a bit in the control register. */
+#define BMS_IRQ_BIT(a)      (1 << (5 - a))
+
+/** IRQ period, corresponds to approx. 30 Hz. */
+#define BMS_IRQ_PERIOD_MS   34
+
+/** Default IRQ setting. */
+#define BMS_DEFAULT_IRQ     3
+
+/** The saved state version. */
+#define BMS_SAVED_STATE_VERSION     1
+
+
+/*********************************************************************************************************************************
+*   Structures and Typedefs                                                                                                      *
+*********************************************************************************************************************************/
+/**
+ * The shared Bus Mouse device state.
+ */
+typedef struct MouState
+{
+    /** @name 8255A state
+     * @{ */
+    uint8_t         port_a;
+    uint8_t         port_b;
+    uint8_t         port_c;
+    uint8_t         ctrl_port;
+    uint8_t         cnt_held;   /**< Counters held for reading. */
+    uint8_t         held_dx;
+    uint8_t         held_dy;
+    uint8_t         irq;        /**< The "jumpered" IRQ level. */
+    int32_t         irq_toggle_counter;
+    /** Timer period in milliseconds. */
+    uint32_t        cTimerPeriodMs;
+    /** Mouse timer handle. */
+    TMTIMERHANDLE   hMouseTimer;
+    /** @} */
+
+    /** @name mouse state
+     * @{ */
+    int32_t         disable_counter;
+    int32_t         mouse_dx; /* current values, needed for 'poll' mode */
+    int32_t         mouse_dy;
+    uint8_t         mouse_enabled;
+    uint8_t         mouse_buttons;
+    uint8_t         mouse_buttons_reported;
+    uint8_t         bAlignment;
+    /** @}  */
+
+    /** The I/O ports registration. */
+    IOMIOPORTHANDLE hIoPorts;
+
+} MouState, BMSSTATE;
+/** Pointer to the shared Bus Mouse device state.  */
+typedef BMSSTATE *PBMSSTATE;
+
+
+/**
+ * The ring-3 Bus Mouse device state.
+ */
+typedef struct BMSSTATER3
+{
+    /** Pointer to the device instance.
+     * @note Only for getting our bearings in an interface method. */
+    PPDMDEVINSR3    pDevIns;
+
+    /**
+     * Mouse port - LUN#0.
+     *
+     * @implements  PDMIBASE
+     * @implements  PDMIMOUSEPORT
+     */
+    struct
+    {
+        /** The base interface for the mouse port. */
+        PDMIBASE                            IBase;
+        /** The mouse port base interface. */
+        PDMIMOUSEPORT                       IPort;
+
+        /** The base interface of the attached mouse driver. */
+        R3PTRTYPE(PPDMIBASE)                pDrvBase;
+        /** The mouse interface of the attached mouse driver. */
+        R3PTRTYPE(PPDMIMOUSECONNECTOR)      pDrv;
+    } Mouse;
+} BMSSTATER3;
+/** Pointer to the ring-3 Bus Mouse device state.  */
+typedef BMSSTATER3 *PBMSSTATER3;
+
+
+#ifndef VBOX_DEVICE_STRUCT_TESTCASE
+
+# ifdef IN_RING3
+
+/**
+ * Report a change in status down the driver chain.
+ *
+ * We want to report the mouse as enabled if and only if the guest is "using"
+ * it. That way, other devices (e.g. a PS/2 or USB mouse) can receive mouse
+ * events when the bus mouse is disabled. Enabling interrupts constitutes
+ * enabling the bus mouse. The mouse is considered disabled if interrupts are
+ * disabled for several consecutive mouse timer ticks; this is because the
+ * interrupt handler in the guest typically temporarily disables interrupts and
+ * we do not want to toggle the enabled/disabled state more often than
+ * necessary.
+ */
+static void bmsR3UpdateDownstreamStatus(PBMSSTATE pThis, PBMSSTATER3 pThisCC)
+{
+    PPDMIMOUSECONNECTOR pDrv = pThisCC->Mouse.pDrv;
+    bool fEnabled = !!pThis->mouse_enabled;
+    if (pDrv)   /* pDrv may be NULL if no mouse interface attached. */
+        pDrv->pfnReportModes(pDrv, fEnabled, false, false, false);
+}
+
+/**
+ * Process a mouse event coming from the host.
+ */
+static void bmsR3MouseEvent(PBMSSTATE pThis, int dx, int dy, int dz, int dw, int buttons_state)
+{
+    LogRel3(("%s: dx=%d, dy=%d, dz=%d, dw=%d, buttons_state=0x%x\n",
+             __PRETTY_FUNCTION__, dx, dy, dz, dw, buttons_state));
+
+    /* Only record X/Y movement and buttons. */
+    pThis->mouse_dx += dx;
+    pThis->mouse_dy += dy;
+    pThis->mouse_buttons = buttons_state;
+}
+
+/**
+ * @callback_method_impl{FNTMTIMERDEV}
+ */
+static DECLCALLBACK(void) bmsR3TimerCallback(PPDMDEVINS pDevIns, TMTIMERHANDLE hTimer, void *pvUser)
+{
+    PBMSSTATE   pThis   = PDMDEVINS_2_DATA(pDevIns, PBMSSTATE);
+    PBMSSTATER3 pThisCC = PDMDEVINS_2_DATA_CC(pDevIns, PBMSSTATER3);
+    uint8_t     irq_bit;
+    RT_NOREF(pvUser);
+    Assert(hTimer == pThis->hMouseTimer);
+
+    /* Toggle the IRQ line if interrupts are enabled. */
+    irq_bit = BMS_IRQ_BIT(pThis->irq);
+
+    if (pThis->port_c & irq_bit)
+    {
+        if (!(pThis->port_c & BMS_CTL_INT_DIS))
+            PDMDevHlpISASetIrq(pDevIns, pThis->irq, PDM_IRQ_LEVEL_LOW);
+        pThis->port_c &= ~irq_bit;
+    }
+    else
+    {
+        pThis->port_c |= irq_bit;
+        if (!(pThis->port_c & BMS_CTL_INT_DIS))
+            PDMDevHlpISASetIrq(pDevIns, pThis->irq, PDM_IRQ_LEVEL_HIGH);
+    }
+
+    /* Handle enabling/disabling of the mouse interface. */
+    if (pThis->port_c & BMS_CTL_INT_DIS)
+    {
+        if (pThis->disable_counter)
+            --pThis->disable_counter;
+
+        if (pThis->disable_counter == 0 && pThis->mouse_enabled)
+        {
+            pThis->mouse_enabled = false;
+            bmsR3UpdateDownstreamStatus(pThis, pThisCC);
+        }
+    }
+    else
+    {
+        pThis->disable_counter = 8; /* Re-arm the disable countdown. */
+        if (!pThis->mouse_enabled)
+        {
+            pThis->mouse_enabled = true;
+            bmsR3UpdateDownstreamStatus(pThis, pThisCC);
+        }
+    }
+
+    /* Re-arm the timer. */
+    PDMDevHlpTimerSetMillies(pDevIns, hTimer, pThis->cTimerPeriodMs);
+}
+
+# endif /* IN_RING3 */
+
+static void bmsSetReportedButtons(PBMSSTATE pThis, unsigned fButtons, unsigned fButtonMask)
+{
+    pThis->mouse_buttons_reported |= (fButtons & fButtonMask);
+    pThis->mouse_buttons_reported &= (fButtons | ~fButtonMask);
+}
+
+/**
+ * Update the internal state after a write to port C.
+ */
+static void bmsUpdateCtrl(PPDMDEVINS pDevIns, PBMSSTATE pThis)
+{
+    int32_t     dx, dy;
+
+    /* If the controller is in hold state, transfer data from counters. */
+    if (pThis->port_c & BMS_CTL_HOLD)
+    {
+        if (!pThis->cnt_held)
+        {
+            pThis->cnt_held = true;
+            dx = pThis->mouse_dx < 0 ? RT_MAX(pThis->mouse_dx, -128)
+                                     : RT_MIN(pThis->mouse_dx, 127);
+            dy = pThis->mouse_dy < 0 ? RT_MAX(pThis->mouse_dy, -128)
+                                     : RT_MIN(pThis->mouse_dy, 127);
+            pThis->mouse_dx -= dx;
+            pThis->mouse_dy -= dy;
+            bmsSetReportedButtons(pThis, pThis->mouse_buttons & 0x07, 0x07);
+
+            /* Force type conversion. */
+            pThis->held_dx = dx;
+            pThis->held_dy = dy;
+        }
+    }
+    else
+        pThis->cnt_held = false;
+
+    /* Move the appropriate nibble into port A. */
+    if (pThis->cnt_held)
+    {
+        if (pThis->port_c & BMS_CTL_SEL_Y)
+        {
+            if (pThis->port_c & BMS_CTL_SEL_HIGH)
+                pThis->port_a = pThis->held_dy >> 4;
+            else
+                pThis->port_a = pThis->held_dy & 0xF;
+        }
+        else
+        {
+            if (pThis->port_c & BMS_CTL_SEL_HIGH)
+                pThis->port_a = pThis->held_dx >> 4;
+            else
+                pThis->port_a = pThis->held_dx & 0xF;
+        }
+        /* And update the button bits. */
+        pThis->port_a |= pThis->mouse_buttons & 1 ? 0 : BMS_DATA_B1_UP;
+        pThis->port_a |= pThis->mouse_buttons & 2 ? 0 : BMS_DATA_B3_UP;
+        pThis->port_a |= pThis->mouse_buttons & 4 ? 0 : BMS_DATA_B2_UP;
+    }
+    /* Immediately clear the IRQ if necessary. */
+    if (pThis->port_c & BMS_CTL_INT_DIS)
+    {
+        PDMDevHlpISASetIrq(pDevIns, pThis->irq, PDM_IRQ_LEVEL_LOW);
+        pThis->port_c &= ~BMS_IRQ_BIT(pThis->irq);
+    }
+}
+
+/**
+ * @callback_method_impl{FNIOMIOPORTNEWIN}
+ */
+static DECLCALLBACK(VBOXSTRICTRC) bmsIoPortRead(PPDMDEVINS pDevIns, void *pvUser, RTIOPORT offPort, uint32_t *pu32, unsigned cb)
+{
+    RT_NOREF(pvUser);
+    if (cb == 1)
+    {
+        PBMSSTATE pThis = PDMDEVINS_2_DATA(pDevIns, PBMSSTATE);
+        uint32_t uValue;
+
+        switch (offPort)
+        {
+            case BMS_PORT_DATA:
+                /* Read port A. */
+                uValue = pThis->port_a;
+                break;
+            case BMS_PORT_SIG:
+                /* Read port B. */
+                uValue = pThis->port_b;
+                break;
+            case BMS_PORT_CTRL:
+                /* Read port C. */
+                uValue = pThis->port_c;
+                /* Some Microsoft driver code reads the control port 10,000 times when
+                 * determining the IRQ level. This can occur faster than the IRQ line
+                 * transitions and the detection fails. To work around this, we force
+                 * the IRQ bit to toggle every once in a while.
+                 */
+                if (pThis->irq_toggle_counter)
+                    pThis->irq_toggle_counter--;
+                else
+                {
+                    pThis->irq_toggle_counter = 1000;
+                    uValue ^= BMS_IRQ_BIT(pThis->irq);
+                }
+                break;
+            case BMS_PORT_INIT:
+                /* Read the 8255A control port. */
+                uValue = pThis->ctrl_port;
+                break;
+            default:
+                ASSERT_GUEST_MSG_FAILED(("invalid port %#x\n", offPort));
+                uValue = 0xff;
+                break;
+        }
+
+        *pu32 = uValue;
+        Log2(("mouIoPortRead: offPort=%#x+%x cb=%d *pu32=%#x\n", BMS_IO_BASE, offPort, cb, uValue));
+        LogRel3(("mouIoPortRead: read port %u: %#04x\n", offPort, uValue));
+        return VINF_SUCCESS;
+    }
+    ASSERT_GUEST_MSG_FAILED(("offPort=%#x cb=%d\n", offPort, cb));
+    return VERR_IOM_IOPORT_UNUSED;
+}
+
+/**
+ * @callback_method_impl{FNIOMIOPORTNEWOUT}
+ */
+static DECLCALLBACK(VBOXSTRICTRC) bmsIoPortWrite(PPDMDEVINS pDevIns, void *pvUser, RTIOPORT offPort, uint32_t u32, unsigned cb)
+{
+    RT_NOREF(pvUser);
+    if (cb == 1)
+    {
+        PBMSSTATE pThis = PDMDEVINS_2_DATA(pDevIns, PBMSSTATE);
+        LogRel3(("mouIoPortWrite: write port %u: %#04x\n", offPort, u32));
+
+        switch (offPort)
+        {
+            case BMS_PORT_SIG:
+                /* Update port B. */
+                pThis->port_b = u32;
+                break;
+            case BMS_PORT_DATA:
+                /* Do nothing, port A is not writable. */
+                break;
+            case BMS_PORT_INIT:
+                pThis->ctrl_port = u32;
+                break;
+            case BMS_PORT_CTRL:
+                /* Update the high nibble of port C. */
+                pThis->port_c = (u32 & 0xF0) | (pThis->port_c & 0x0F);
+                bmsUpdateCtrl(pDevIns, pThis);
+                break;
+            default:
+                ASSERT_GUEST_MSG_FAILED(("invalid port %#x\n", offPort));
+                break;
+        }
+
+        Log2(("mouIoPortWrite: offPort=%#x+%u cb=%d u32=%#x\n", BMS_IO_BASE, offPort, cb, u32));
+    }
+    else
+        ASSERT_GUEST_MSG_FAILED(("offPort=%#x cb=%d\n", offPort, cb));
+    return VINF_SUCCESS;
+}
+
+# ifdef IN_RING3
+
+/**
+ * @callback_method_impl{FNSSMDEVSAVEEXEC}
+ */
+static DECLCALLBACK(int) bmsR3SaveExec(PPDMDEVINS pDevIns, PSSMHANDLE pSSMHandle)
+{
+    PBMSSTATE       pThis = PDMDEVINS_2_DATA(pDevIns, PBMSSTATE);
+    PCPDMDEVHLPR3   pHlp  = pDevIns->pHlpR3;
+
+    /* 8255A state. */
+    pHlp->pfnSSMPutU8(pSSMHandle, pThis->port_a);
+    pHlp->pfnSSMPutU8(pSSMHandle, pThis->port_b);
+    pHlp->pfnSSMPutU8(pSSMHandle, pThis->port_c);
+    pHlp->pfnSSMPutU8(pSSMHandle, pThis->ctrl_port);
+    /* Other device state. */
+    pHlp->pfnSSMPutU8(pSSMHandle, pThis->cnt_held);
+    pHlp->pfnSSMPutU8(pSSMHandle, pThis->held_dx);
+    pHlp->pfnSSMPutU8(pSSMHandle, pThis->held_dy);
+    pHlp->pfnSSMPutU8(pSSMHandle, pThis->irq);
+    pHlp->pfnSSMPutU32(pSSMHandle, pThis->cTimerPeriodMs);
+    /* Current mouse state deltas. */
+    pHlp->pfnSSMPutS32(pSSMHandle, pThis->mouse_dx);
+    pHlp->pfnSSMPutS32(pSSMHandle, pThis->mouse_dy);
+    pHlp->pfnSSMPutU8(pSSMHandle, pThis->mouse_buttons_reported);
+    /* Timer. */
+    return PDMDevHlpTimerSave(pDevIns, pThis->hMouseTimer, pSSMHandle);
+}
+
+/**
+ * @callback_method_impl{FNSSMDEVLOADEXEC}
+ */
+static DECLCALLBACK(int) bmsR3LoadExec(PPDMDEVINS pDevIns, PSSMHANDLE pSSMHandle, uint32_t uVersion, uint32_t uPass)
+{
+    PBMSSTATE       pThis = PDMDEVINS_2_DATA(pDevIns, PBMSSTATE);
+    PCPDMDEVHLPR3   pHlp  = pDevIns->pHlpR3;
+
+    Assert(uPass == SSM_PASS_FINAL); NOREF(uPass);
+
+    if (uVersion > BMS_SAVED_STATE_VERSION)
+        return VERR_SSM_UNSUPPORTED_DATA_UNIT_VERSION;
+
+    /* 8255A state. */
+    pHlp->pfnSSMGetU8(pSSMHandle, &pThis->port_a);
+    pHlp->pfnSSMGetU8(pSSMHandle, &pThis->port_b);
+    pHlp->pfnSSMGetU8(pSSMHandle, &pThis->port_c);
+    pHlp->pfnSSMGetU8(pSSMHandle, &pThis->ctrl_port);
+    /* Other device state. */
+    pHlp->pfnSSMGetU8(pSSMHandle, &pThis->cnt_held);
+    pHlp->pfnSSMGetU8(pSSMHandle, &pThis->held_dx);
+    pHlp->pfnSSMGetU8(pSSMHandle, &pThis->held_dy);
+    pHlp->pfnSSMGetU8(pSSMHandle, &pThis->irq);
+    pHlp->pfnSSMGetU32(pSSMHandle, &pThis->cTimerPeriodMs);
+    /* Current mouse state deltas. */
+    pHlp->pfnSSMGetS32(pSSMHandle, &pThis->mouse_dx);
+    pHlp->pfnSSMGetS32(pSSMHandle, &pThis->mouse_dy);
+    pHlp->pfnSSMGetU8(pSSMHandle, &pThis->mouse_buttons_reported);
+    /* Timer. */
+    return PDMDevHlpTimerLoad(pDevIns, pThis->hMouseTimer, pSSMHandle);
+}
+
+/**
+ * Reset notification.
+ *
+ * @returns VBox status code.
+ * @param   pDevIns     The device instance data.
+ */
+static DECLCALLBACK(void) bmsR3Reset(PPDMDEVINS pDevIns)
+{
+    PBMSSTATE   pThis   = PDMDEVINS_2_DATA(pDevIns, PBMSSTATE);
+    PBMSSTATER3 pThisCC = PDMDEVINS_2_DATA_CC(pDevIns, PBMSSTATER3);
+
+    /* Reinitialize the timer. */
+    pThis->cTimerPeriodMs = BMS_IRQ_PERIOD_MS / 2;
+    PDMDevHlpTimerSetMillies(pDevIns, pThis->hMouseTimer, pThis->cTimerPeriodMs);
+
+    /* Clear the device setup. */
+    pThis->port_a = pThis->port_b = 0;
+    pThis->port_c = BMS_CTL_INT_DIS;    /* Interrupts disabled. */
+    pThis->ctrl_port = 0x91;            /* Default 8255A setup. */
+
+    /* Clear motion/button state. */
+    pThis->cnt_held = false;
+    pThis->mouse_dx = pThis->mouse_dy = 0;
+    pThis->mouse_buttons = 0;
+    pThis->mouse_buttons_reported = 0;
+    pThis->disable_counter = 0;
+    pThis->irq_toggle_counter = 1000;
+
+    if (pThis->mouse_enabled)
+    {
+        pThis->mouse_enabled = false;
+        bmsR3UpdateDownstreamStatus(pThis, pThisCC);
+    }
+}
+
+
+/* -=-=-=-=-=- Mouse: IBase  -=-=-=-=-=- */
+
+/**
+ * @interface_method_impl{PDMIBASE,pfnQueryInterface}
+ */
+static DECLCALLBACK(void *) bmsR3Base_QueryMouseInterface(PPDMIBASE pInterface, const char *pszIID)
+{
+    PBMSSTATER3 pThisCC = RT_FROM_MEMBER(pInterface, BMSSTATER3, Mouse.IBase);
+    PDMIBASE_RETURN_INTERFACE(pszIID, PDMIBASE, &pThisCC->Mouse.IBase);
+    PDMIBASE_RETURN_INTERFACE(pszIID, PDMIMOUSEPORT, &pThisCC->Mouse.IPort);
+    return NULL;
+}
+
+
+/* -=-=-=-=-=- Mouse: IMousePort  -=-=-=-=-=- */
+
+/**
+ * @interface_method_impl{PDMIMOUSEPORT,pfnPutEvent}
+ */
+static DECLCALLBACK(int) bmsR3MousePort_PutEvent(PPDMIMOUSEPORT pInterface, int32_t dx,
+                                                 int32_t dy, int32_t dz, int32_t dw,
+                                                 uint32_t fButtons)
+{
+    PBMSSTATER3 pThisCC = RT_FROM_MEMBER(pInterface, BMSSTATER3, Mouse.IPort);
+    PPDMDEVINS  pDevIns = pThisCC->pDevIns;
+    PBMSSTATE   pThis   = PDMDEVINS_2_DATA(pDevIns, PBMSSTATE);
+    int rc = PDMDevHlpCritSectEnter(pDevIns, pDevIns->CTX_SUFF(pCritSectRo), VERR_SEM_BUSY);
+    PDM_CRITSECT_RELEASE_ASSERT_RC_DEV(pDevIns, pDevIns->CTX_SUFF(pCritSectRo), rc);
+
+    bmsR3MouseEvent(pThis, dx, dy, dz, dw, fButtons);
+
+    PDMDevHlpCritSectLeave(pDevIns, pDevIns->CTX_SUFF(pCritSectRo));
+    return VINF_SUCCESS;
+}
+
+/**
+ * @interface_method_impl{PDMIMOUSEPORT,pfnPutEventAbs}
+ */
+static DECLCALLBACK(int) bmsR3MousePort_PutEventAbs(PPDMIMOUSEPORT pInterface, uint32_t x, uint32_t y,
+                                                    int32_t dz, int32_t dw, uint32_t fButtons)
+{
+    RT_NOREF(pInterface, x, y, dz, dw, fButtons);
+    AssertFailedReturn(VERR_NOT_SUPPORTED);
+}
+
+/**
+ * @interface_method_impl{PDMIMOUSEPORT,pfnPutEventMultiTouch}
+ */
+static DECLCALLBACK(int) bmsR3MousePort_PutEventMultiTouch(PPDMIMOUSEPORT pInterface, uint8_t cContacts,
+                                                           const uint64_t *pau64Contacts, uint32_t u32ScanTime)
+{
+    RT_NOREF(pInterface, cContacts, pau64Contacts, u32ScanTime);
+    AssertFailedReturn(VERR_NOT_SUPPORTED);
+}
+
+/* -=-=-=-=-=- setup code -=-=-=-=-=- */
+
+
+/**
+ * @interface_method_impl{PDMDEVREGR3,pfnAttach}
+ */
+static DECLCALLBACK(int) bmsR3Attach(PPDMDEVINS pDevIns, unsigned iLUN, uint32_t fFlags)
+{
+    PBMSSTATER3 pThisCC = PDMDEVINS_2_DATA_CC(pDevIns, PBMSSTATER3);
+    int         rc;
+
+    AssertMsgReturn(fFlags & PDM_TACH_FLAGS_NOT_HOT_PLUG,
+                    ("Bus mouse device does not support hotplugging\n"),
+                    VERR_INVALID_PARAMETER);
+
+    switch (iLUN)
+    {
+        /* LUN #0: mouse */
+        case 0:
+            rc = PDMDevHlpDriverAttach(pDevIns, iLUN, &pThisCC->Mouse.IBase, &pThisCC->Mouse.pDrvBase, "Bus Mouse Port");
+            if (RT_SUCCESS(rc))
+            {
+                pThisCC->Mouse.pDrv = PDMIBASE_QUERY_INTERFACE(pThisCC->Mouse.pDrvBase, PDMIMOUSECONNECTOR);
+                if (!pThisCC->Mouse.pDrv)
+                {
+                    AssertLogRelMsgFailed(("LUN #0 doesn't have a mouse interface! rc=%Rrc\n", rc));
+                    rc = VERR_PDM_MISSING_INTERFACE;
+                }
+            }
+            else if (rc == VERR_PDM_NO_ATTACHED_DRIVER)
+            {
+                LogRel(("%s/%d: Warning: no driver attached to LUN #0!\n", pDevIns->pReg->szName, pDevIns->iInstance));
+                rc = VINF_SUCCESS;
+            }
+            else
+                AssertLogRelMsgFailed(("Failed to attach LUN #0! rc=%Rrc\n", rc));
+            break;
+
+        default:
+            AssertMsgFailed(("Invalid LUN #%d\n", iLUN));
+            return VERR_PDM_NO_SUCH_LUN;
+    }
+
+    return rc;
+}
+
+
+/**
+ * @interface_method_impl{PDMDEVREGR3,pfnDetach}
+ */
+static DECLCALLBACK(void) bmsR3Detach(PPDMDEVINS pDevIns, unsigned iLUN, uint32_t fFlags)
+{
+#  if 0
+    /*
+     * Reset the interfaces and update the controller state.
+     */
+    PBMSSTATE   pThis = PDMDEVINS_2_DATA(pDevIns, PBMSSTATE);
+    switch (iLUN)
+    {
+        /* LUN #0: mouse */
+        case 0:
+            pThis->Mouse.pDrv = NULL;
+            pThis->Mouse.pDrvBase = NULL;
+            break;
+
+        default:
+            AssertMsgFailed(("Invalid LUN #%d\n", iLUN));
+            break;
+    }
+#  else
+    RT_NOREF(pDevIns, iLUN, fFlags);
+#  endif
+}
+
+
+/**
+ * @interface_method_impl{PDMDEVREG,pfnConstruct}
+ */
+static DECLCALLBACK(int) bmsR3Construct(PPDMDEVINS pDevIns, int iInstance, PCFGMNODE pCfg)
+{
+    PDMDEV_CHECK_VERSIONS_RETURN(pDevIns);
+    PBMSSTATE       pThis   = PDMDEVINS_2_DATA(pDevIns, PBMSSTATE);
+    PBMSSTATER3     pThisCC = PDMDEVINS_2_DATA_CC(pDevIns, PBMSSTATER3);
+    PCPDMDEVHLPR3   pHlp    = pDevIns->pHlpR3;
+    int             rc;
+    RT_NOREF(iInstance);
+
+    Assert(iInstance == 0);
+
+    /*
+     * Validate and read the configuration.
+     */
+    PDMDEV_VALIDATE_CONFIG_RETURN(pDevIns, "IRQ", "");
+
+    rc = pHlp->pfnCFGMQueryU8Def(pCfg, "IRQ", &pThis->irq, BMS_DEFAULT_IRQ);
+    if (RT_FAILURE(rc))
+        return PDMDEV_SET_ERROR(pDevIns, rc, N_("Failed to query \"IRQ\" from the config"));
+    if (pThis->irq < 2 || pThis->irq > 5)
+        return PDMDEV_SET_ERROR(pDevIns, rc, N_("Invalid \"IRQ\" config setting"));
+
+    Log(("busmouse: IRQ=%u fRCEnabled=%RTbool fR0Enabled=%RTbool\n", pThis->irq, pDevIns->fRCEnabled, pDevIns->fR0Enabled));
+
+    /*
+     * Initialize the interfaces.
+     */
+    pThisCC->pDevIns                            = pDevIns;
+    pThisCC->Mouse.IBase.pfnQueryInterface      = bmsR3Base_QueryMouseInterface;
+    pThisCC->Mouse.IPort.pfnPutEvent            = bmsR3MousePort_PutEvent;
+    pThisCC->Mouse.IPort.pfnPutEventAbs         = bmsR3MousePort_PutEventAbs;
+    pThisCC->Mouse.IPort.pfnPutEventTouchScreen = bmsR3MousePort_PutEventMultiTouch;
+    pThisCC->Mouse.IPort.pfnPutEventTouchPad    = bmsR3MousePort_PutEventMultiTouch;
+
+    /*
+     * Create the interrupt timer.
+     */
+    rc = PDMDevHlpTimerCreate(pDevIns, TMCLOCK_VIRTUAL, bmsR3TimerCallback, pThis,
+                              TMTIMER_FLAGS_DEFAULT_CRIT_SECT | TMTIMER_FLAGS_NO_RING0, "Bus Mouse", &pThis->hMouseTimer);
+    AssertRCReturn(rc, rc);
+
+    /*
+     * Register I/O ports.
+     */
+    static const IOMIOPORTDESC s_aDescs[] =
+    {
+        { "DATA", "DATA", NULL, NULL },
+        { "SIG",  "SIG",  NULL, NULL },
+        { "CTRL", "CTRL", NULL, NULL },
+        { "INIT", "INIT", NULL, NULL },
+        { NULL,   NULL,   NULL, NULL }
+    };
+    rc = PDMDevHlpIoPortCreateAndMap(pDevIns, BMS_IO_BASE, BMS_IO_SIZE, bmsIoPortWrite, bmsIoPortRead,
+                                     "Bus Mouse", s_aDescs, &pThis->hIoPorts);
+    AssertRCReturn(rc, rc);
+
+    /*
+     * Register saved state.
+     */
+    rc = PDMDevHlpSSMRegister(pDevIns, BMS_SAVED_STATE_VERSION, sizeof(*pThis), bmsR3SaveExec, bmsR3LoadExec);
+    AssertRCReturn(rc, rc);
+
+    /*
+     * Attach to the mouse driver.
+     */
+    rc = bmsR3Attach(pDevIns, 0, PDM_TACH_FLAGS_NOT_HOT_PLUG);
+    AssertRCReturn(rc, rc);
+
+    /*
+     * Initialize the device state.
+     */
+    bmsR3Reset(pDevIns);
+
+    return VINF_SUCCESS;
+}
+
+# else /* !IN_RING3 */
+
+/**
+ * @callback_method_impl{PDMDEVREGR0,pfnConstruct}
+ */
+static DECLCALLBACK(int) bmsRZConstruct(PPDMDEVINS pDevIns)
+{
+    PDMDEV_CHECK_VERSIONS_RETURN(pDevIns);
+    PBMSSTATE   pThis = PDMDEVINS_2_DATA(pDevIns, PBMSSTATE);
+
+    int rc = PDMDevHlpIoPortSetUpContext(pDevIns, pThis->hIoPorts, bmsIoPortWrite, bmsIoPortRead, NULL /*pvUser*/);
+    AssertRCReturn(rc, rc);
+
+    return VINF_SUCCESS;
+}
+
+# endif /* !IN_RING3 */
+
+
+/**
+ * The device registration structure.
+ */
+static const PDMDEVREG g_DeviceBusMouse =
+{
+    /* .u32Version = */             PDM_DEVREG_VERSION,
+    /* .uReserved0 = */             0,
+    /* .szName = */                 "busmouse",
+    /* .fFlags = */                 PDM_DEVREG_FLAGS_DEFAULT_BITS /** @todo | PDM_DEVREG_FLAGS_RZ */ | PDM_DEVREG_FLAGS_NEW_STYLE,
+    /* .fClass = */                 PDM_DEVREG_CLASS_INPUT,
+    /* .cMaxInstances = */          1,
+    /* .uSharedVersion = */         42,
+    /* .cbInstanceShared = */       sizeof(BMSSTATE),
+    /* .cbInstanceCC = */           CTX_EXPR(sizeof(BMSSTATER3), 0, 0),
+    /* .cbInstanceRC = */           0,
+    /* .cMaxPciDevices = */         0,
+    /* .cMaxMsixVectors = */        0,
+    /* .pszDescription = */         "Microsoft Bus Mouse controller. LUN #0 is the mouse connector.",
+# if defined(IN_RING3)
+    /* .pszRCMod = */               "VBoxDDRC.rc",
+    /* .pszR0Mod = */               "VBoxDDR0.r0",
+    /* .pfnConstruct = */           bmsR3Construct,
+    /* .pfnDestruct = */            NULL,
+    /* .pfnRelocate = */            NULL,
+    /* .pfnMemSetup = */            NULL,
+    /* .pfnPowerOn = */             NULL,
+    /* .pfnReset = */               bmsR3Reset,
+    /* .pfnSuspend = */             NULL,
+    /* .pfnResume = */              NULL,
+    /* .pfnAttach = */              bmsR3Attach,
+    /* .pfnDetach = */              bmsR3Detach,
+    /* .pfnQueryInterface = */      NULL,
+    /* .pfnInitComplete = */        NULL,
+    /* .pfnPowerOff = */            NULL,
+    /* .pfnSoftReset = */           NULL,
+    /* .pfnReserved0 = */           NULL,
+    /* .pfnReserved1 = */           NULL,
+    /* .pfnReserved2 = */           NULL,
+    /* .pfnReserved3 = */           NULL,
+    /* .pfnReserved4 = */           NULL,
+    /* .pfnReserved5 = */           NULL,
+    /* .pfnReserved6 = */           NULL,
+    /* .pfnReserved7 = */           NULL,
+# elif defined(IN_RING0)
+    /* .pfnEarlyConstruct = */      NULL,
+    /* .pfnConstruct = */           bmsRZConstruct,
+    /* .pfnDestruct = */            NULL,
+    /* .pfnFinalDestruct = */       NULL,
+    /* .pfnRequest = */             NULL,
+    /* .pfnReserved0 = */           NULL,
+    /* .pfnReserved1 = */           NULL,
+    /* .pfnReserved2 = */           NULL,
+    /* .pfnReserved3 = */           NULL,
+    /* .pfnReserved4 = */           NULL,
+    /* .pfnReserved5 = */           NULL,
+    /* .pfnReserved6 = */           NULL,
+    /* .pfnReserved7 = */           NULL,
+# elif defined(IN_RC)
+    /* .pfnConstruct = */           bmsRZConstruct,
+    /* .pfnReserved0 = */           NULL,
+    /* .pfnReserved1 = */           NULL,
+    /* .pfnReserved2 = */           NULL,
+    /* .pfnReserved3 = */           NULL,
+    /* .pfnReserved4 = */           NULL,
+    /* .pfnReserved5 = */           NULL,
+    /* .pfnReserved6 = */           NULL,
+    /* .pfnReserved7 = */           NULL,
+# else
+#  error "Not in IN_RING3, IN_RING0 or IN_RC!"
+# endif
+    /* .u32VersionEnd = */          PDM_DEVREG_VERSION
+};
+
+# ifdef VBOX_IN_EXTPACK_R3
+
+/**
+ * @callback_method_impl{FNPDMVBOXDEVICESREGISTER}
+ */
+extern "C" DECLEXPORT(int) VBoxDevicesRegister(PPDMDEVREGCB pCallbacks, uint32_t u32Version)
+{
+    AssertLogRelMsgReturn(u32Version >= VBOX_VERSION,
+                          ("u32Version=%#x VBOX_VERSION=%#x\n", u32Version, VBOX_VERSION),
+                          VERR_EXTPACK_VBOX_VERSION_MISMATCH);
+    AssertLogRelMsgReturn(pCallbacks->u32Version == PDM_DEVREG_CB_VERSION,
+                          ("pCallbacks->u32Version=%#x PDM_DEVREG_CB_VERSION=%#x\n", pCallbacks->u32Version, PDM_DEVREG_CB_VERSION),
+                          VERR_VERSION_MISMATCH);
+
+    return pCallbacks->pfnRegister(pCallbacks, &g_DeviceBusMouse);
+}
+
+# else  /* !VBOX_IN_EXTPACK_R3 */
+
+/** Pointer to the ring-0 device registrations for the Bus Mouse. */
+static PCPDMDEVREGR0 g_apDevRegs[] =
+{
+    &g_DeviceBusMouse,
+};
+
+/** Module device registration record for the Bus Mouse. */
+static PDMDEVMODREGR0 g_ModDevReg =
+{
+    /* .u32Version = */ PDM_DEVMODREGR0_VERSION,
+    /* .cDevRegs = */   RT_ELEMENTS(g_apDevRegs),
+    /* .papDevRegs = */ &g_apDevRegs[0],
+    /* .hMod = */       NULL,
+    /* .ListEntry = */  { NULL, NULL },
+};
+
+DECLEXPORT(int)  ModuleInit(void *hMod)
+{
+    LogFlow(("VBoxBusMouseRZ/ModuleInit: %p\n", hMod));
+    return PDMR0DeviceRegisterModule(hMod, &g_ModDevReg);
+}
+
+DECLEXPORT(void) ModuleTerm(void *hMod)
+{
+    LogFlow(("VBoxBusMouseRZ/ModuleTerm: %p\n", hMod));
+    PDMR0DeviceDeregisterModule(hMod, &g_ModDevReg);
+}
+
+# endif  /* !VBOX_IN_EXTPACK_R3 */
+
+#endif /* !VBOX_DEVICE_STRUCT_TESTCASE */
+
diff --git a/src/VBox/ExtPacks/BusMouseSample/ExtPack.xml b/src/VBox/ExtPacks/BusMouseSample/ExtPack.xml
new file mode 100644
index 00000000..0ceba0a5
--- /dev/null
+++ b/src/VBox/ExtPacks/BusMouseSample/ExtPack.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<VirtualBoxExtensionPack xmlns="http://www.virtualbox.org/VirtualBoxExtensionPack" version="1.0">
+    <Name>BusMouse</Name>
+    <Description>The bus mouse sample extension pack.</Description>
+    <Version revision="@VBOX_SVN_REV@">@VBOX_VERSION_STRING@</Version>
+    <MainModule>VBoxBusMouseMain</MainModule>
+    <MainVMModule>VBoxBusMouseMainVM</MainVMModule>
+    <ShowLicense/>
+</VirtualBoxExtensionPack>
+
diff --git a/src/VBox/ExtPacks/BusMouseSample/Makefile.kmk b/src/VBox/ExtPacks/BusMouseSample/Makefile.kmk
new file mode 100644
index 00000000..16118996
--- /dev/null
+++ b/src/VBox/ExtPacks/BusMouseSample/Makefile.kmk
@@ -0,0 +1,203 @@
+# $Id: Makefile.kmk $
+## @file
+# Sub-Makefile for the Bus Mouse Extension Pack Sample.
+#
+
+#
+# Copyright (C) 2010-2023 Oracle and/or its affiliates.
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation
+# files (the "Software"), to deal in the Software without
+# restriction, including without limitation the rights to use,
+# copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following
+# conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+#
+
+SUB_DEPTH = ../../../..
+include $(KBUILD_PATH)/subheader.kmk
+
+#
+# Extend the extension pack templates.
+#
+TEMPLATE_VBoxR3ExtPackBusMouse          = For the ring-3 context modules in the Bus Mouse extension pack.
+TEMPLATE_VBoxR3ExtPackBusMouse_EXTENDS  = VBoxR3ExtPack
+TEMPLATE_VBoxR3ExtPackBusMouse_INST     = $(INST_EXTPACK)BusMouse/$(KBUILD_TARGET).$(KBUILD_TARGET_ARCH)/
+
+TEMPLATE_VBoxR0ExtPackBusMouse          = For the ring-0 context modules in the Bus Mouse extension pack.
+TEMPLATE_VBoxR0ExtPackBusMouse_EXTENDS  = VBoxR0ExtPack
+TEMPLATE_VBoxR0ExtPackBusMouse_INST     = $(INST_EXTPACK)BusMouse/$(KBUILD_TARGET).$(KBUILD_TARGET_ARCH)/
+
+TEMPLATE_VBoxRcExtPackBusMouse          = For the raw-mode context modules in the Bus Mouse extension pack.
+TEMPLATE_VBoxRcExtPackBusMouse_EXTENDS  = VBoxRcExtPack
+TEMPLATE_VBoxRcExtPackBusMouse_INST     = $(INST_EXTPACK)BusMouse/$(KBUILD_TARGET).$(KBUILD_TARGET_ARCH)/
+
+TEMPLATE_VBoxInsExtPackBusMouse         = For the install targets of an extension pack.
+TEMPLATE_VBoxInsExtPackBusMouse_EXTENDS = VBoxR0ExtPack
+TEMPLATE_VBoxInsExtPackBusMouse_INST    = $(INST_EXTPACK)BusMouse/
+
+#
+# Globals.
+#
+VBOX_BUSMOUSE_NAME         = BusMouse
+VBOX_BUSMOUSE_MANGLED_NAME = BusMouse
+VBOX_PATH_EXTPACK_BUSMOUSE = $(PATH_STAGE)/$(INST_EXTPACK)BusMouse
+
+
+#
+# VBoxBusMouseMain - The module which the VirtualBox Main API talks to.
+#
+DLLS += VBoxBusMouseMain
+VBoxBusMouseMain_TEMPLATE = VBoxR3ExtPackBusMouse
+VBoxBusMouseMain_SOURCES = VBoxBusMouseMain.cpp
+VBoxBusMouseMain_DEFS =
+
+
+#
+# VBoxBusMouseMainVM - The module in a VM which the VirtualBox Main API talks to.
+#
+DLLS += VBoxBusMouseMainVM
+VBoxBusMouseMainVM_TEMPLATE = VBoxR3ExtPackBusMouse
+VBoxBusMouseMainVM_SOURCES = VBoxBusMouseMainVM.cpp
+VBoxBusMouseMainVM_DEFS =
+
+
+#
+# The device code.
+#
+DLLS += VBoxBusMouseR3
+VBoxBusMouseR3_TEMPLATE = VBoxR3ExtPackBusMouse
+VBoxBusMouseR3_SOURCES  = DevBusMouse.cpp
+
+ifdef VBOX_WITH_R0_MODULES
+ ifdef VBOX_WITH_VBOXR0_AS_DLL
+  DLLS    += VBoxBusMouseR0
+ else
+  SYSMODS += VBoxBusMouseR0
+ endif
+ VBoxBusMouseR0_TEMPLATE = VBoxR0ExtPackBusMouse
+ VBoxBusMouseR0_SOURCES  = DevBusMouse.cpp
+endif
+
+ifdef VBOX_WITH_RAW_MODE
+ SYSMODS += VBoxBusMouseRC
+ VBoxBusMouseRC_TEMPLATE = VBoxRcExtPackBusMouse
+ VBoxBusMouseRC_SOURCES  = DevBusMouse.cpp
+endif
+
+
+#
+# Install the description.
+#
+INSTALLS += VBoxBusMouseIns
+VBoxBusMouseIns_TEMPLATE = VBoxInsExtPackBusMouse
+VBoxBusMouseIns_SOURCES = \
+	$(VBoxBusMouseIns_0_OUTDIR)/ExtPack.xml
+$(call VBOX_EDIT_VERSION_RULE_FN,VBoxBusMouseIns,ExtPack.xml)
+
+
+#
+# Packing.
+#
+ifndef VBOX_WITHOUT_EXTPACK_BUSMOUSE_PACKING
+ PACKING += $(VBOX_PATH_PACKAGES)/$(VBOX_BUSMOUSE_MANGLED_NAME)-$(VBOX_VERSION_STRING)r$(VBOX_SVN_REV).vbox-extpack
+endif
+
+ifndef VBOX_WITH_EXTPACK_OS_ARCHS
+ ifeq ($(USER),bird) # for now
+  VBOX_WITH_EXTPACK_OS_ARCHS = $(KBUILD_TARGET).$(KBUILD_TARGET_ARCH)
+ endif
+endif
+
+# Build the file list.  The macro takes 1=darwin.x86, 2=dist/VirtualBox.app/Contents/MacOS, 3=dylib
+VBOX_BUSMOUSE_FILES_MACRO = \
+	$(PATH_OUT_BASE)/$(1)/$(KBUILD_TYPE)/$(2)/ExtensionPacks/$(VBOX_BUSMOUSE_MANGLED_NAME)/$(1)/VBoxBusMouseMain.$(3)=>$(1)/VBoxBusMouseMain.$(3) \
+	$(PATH_OUT_BASE)/$(1)/$(KBUILD_TYPE)/$(2)/ExtensionPacks/$(VBOX_BUSMOUSE_MANGLED_NAME)/$(1)/VBoxBusMouseMainVM.$(3)=>$(1)/VBoxBusMouseMainVM.$(3) \
+	$(PATH_OUT_BASE)/$(1)/$(KBUILD_TYPE)/$(2)/ExtensionPacks/$(VBOX_BUSMOUSE_MANGLED_NAME)/$(1)/VBoxBusMouseR3.$(3)=>$(1)/VBoxBusMouseR3.$(3) \
+	$(PATH_OUT_BASE)/$(1)/$(KBUILD_TYPE)/$(2)/ExtensionPacks/$(VBOX_BUSMOUSE_MANGLED_NAME)/$(1)/VBoxBusMouseR0.r0=>$(1)/VBoxBusMouseR0.r0
+ifdef VBOX_WITH_RAW_MODE
+ VBOX_BUSMOUSE_FILES_MACRO += \
+ 	$(PATH_OUT_BASE)/$(1)/$(KBUILD_TYPE)/$(2)/ExtensionPacks/$(VBOX_BUSMOUSE_MANGLED_NAME)/$(1)/VBoxBusMouseRC.rc=>$(1)/VBoxBusMouseRC.rc
+endif
+
+VBOX_BUSMOUSE_FILES := \
+	$(VBOX_PATH_EXTPACK_BUSMOUSE)/ExtPack.xml=>ExtPack.xml
+
+if1of (darwin.amd64, $(VBOX_WITH_EXTPACK_OS_ARCHS))
+ VBOX_BUSMOUSE_FILES += $(call VBOX_BUSMOUSE_FILES_MACRO,darwin.amd64,dist/VirtualBox.app/Contents/MacOS,dylib)
+endif
+if1of (darwin.x86, $(VBOX_WITH_EXTPACK_OS_ARCHS))
+ VBOX_BUSMOUSE_FILES += $(call VBOX_BUSMOUSE_FILES_MACRO,darwin.x86,dist/VirtualBox.app/Contents/MacOS,dylib)
+endif
+if1of (freebsd.amd64, $(VBOX_WITH_EXTPACK_OS_ARCHS))
+ VBOX_BUSMOUSE_FILES += $(call VBOX_BUSMOUSE_FILES_MACRO,freebsd.amd64,bin,so)
+endif
+if1of (freebsd.x86, $(VBOX_WITH_EXTPACK_OS_ARCHS))
+ VBOX_BUSMOUSE_FILES += $(call VBOX_BUSMOUSE_FILES_MACRO,freebsd.x86,bin,so)
+endif
+if1of (linux.amd64, $(VBOX_WITH_EXTPACK_OS_ARCHS))
+ VBOX_BUSMOUSE_FILES += $(call VBOX_BUSMOUSE_FILES_MACRO,linux.amd64,bin,so)
+endif
+if1of (linux.x86, $(VBOX_WITH_EXTPACK_OS_ARCHS))
+ VBOX_BUSMOUSE_FILES += $(call VBOX_BUSMOUSE_FILES_MACRO,linux.x86,bin,so)
+endif
+if1of (os2.x86, $(VBOX_WITH_EXTPACK_OS_ARCHS))
+ VBOX_BUSMOUSE_FILES += $(call VBOX_BUSMOUSE_FILES_MACRO,os2.x86,bin,so)
+endif
+if1of (solaris.amd64, $(VBOX_WITH_EXTPACK_OS_ARCHS))
+ VBOX_BUSMOUSE_FILES += $(call VBOX_BUSMOUSE_FILES_MACRO,solaris.amd64,bin,so)
+endif
+if1of (solaris.x86, $(VBOX_WITH_EXTPACK_OS_ARCHS))
+ VBOX_BUSMOUSE_FILES += $(call VBOX_BUSMOUSE_FILES_MACRO,solaris.x86,bin,so)
+endif
+if1of (win.amd64, $(VBOX_WITH_EXTPACK_OS_ARCHS))
+ VBOX_BUSMOUSE_FILES += $(call VBOX_BUSMOUSE_FILES_MACRO,win.amd64,bin,dll)
+endif
+if1of (win.x86, $(VBOX_WITH_EXTPACK_OS_ARCHS))
+ VBOX_BUSMOUSE_FILES += $(call VBOX_BUSMOUSE_FILES_MACRO,win.x86,bin,dll)
+endif
+
+# Pack it all up using a temporary staging directory.
+$(VBOX_PATH_PACKAGES)/$(VBOX_BUSMOUSE_MANGLED_NAME)-$(VBOX_VERSION_STRING)r$(VBOX_SVN_REV).vbox-extpack: \
+		$$(foreach file, $$(VBOX_BUSMOUSE_FILES), $$(firstword $$(subst =>,$$(SP),$$(file)))) \
+		| $(VBOX_PATH_PACKAGES)/
+	$(RM) -f $(wildcard $(VBOX_PATH_PACKAGES)/$(VBOX_BUSMOUSE_MANGLED_NAME)-*.vbox-extpack) \
+		$(VBoxBusMouseIns_0_OUTDIR)/ExtPack.manifest \
+		$(VBoxBusMouseIns_0_OUTDIR)/ExtPack.signature
+# Stage all the files
+	$(RM) -Rf $(VBoxBusMouseIns_0_OUTDIR)/Stage/
+	$(foreach file, $(VBOX_BUSMOUSE_FILES),\
+		$(NLTAB)$(MKDIR) -p $(dir $(lastword $(subst =>,$(SP)$(VBoxBusMouseIns_0_OUTDIR)/Stage/,$(file)))) \
+		$(NLTAB)$(CP) $(subst =>,$(SP)$(VBoxBusMouseIns_0_OUTDIR)/Stage/,$(file)) )
+# Create the manifest
+	$(VBOX_RTMANIFEST) \
+		--manifest $(VBoxBusMouseIns_0_OUTDIR)/Stage/ExtPack.manifest \
+		--chdir $(VBoxBusMouseIns_0_OUTDIR)/Stage/ \
+		$(foreach file, $(VBOX_BUSMOUSE_FILES), $(lastword $(subst =>,$(SP),$(file))))
+	$(APPEND) $(VBoxBusMouseIns_0_OUTDIR)/Stage/ExtPack.signature "todo"
+	$(CHMOD) a+r \
+		$(VBoxBusMouseIns_0_OUTDIR)/Stage/ExtPack.manifest \
+		$(VBoxBusMouseIns_0_OUTDIR)/Stage/ExtPack.signature
+# Tar it up.
+	tar -cvf - -C $(VBoxBusMouseIns_0_OUTDIR)/Stage/ . | gzip -9c > $@
+# Clean up
+	$(RM) -Rf $(VBoxBusMouseIns_0_OUTDIR)/Stage/
+
+BLDDIRS += $(VBOX_PATH_PACKAGES)/
+
+include $(FILE_KBUILD_SUB_FOOTER)
+
diff --git a/src/VBox/ExtPacks/BusMouseSample/VBoxBusMouseMain.cpp b/src/VBox/ExtPacks/BusMouseSample/VBoxBusMouseMain.cpp
new file mode 100644
index 00000000..4a4e0100
--- /dev/null
+++ b/src/VBox/ExtPacks/BusMouseSample/VBoxBusMouseMain.cpp
@@ -0,0 +1,130 @@
+/* $Id: VBoxBusMouseMain.cpp $ */
+/** @file
+ * Bus Mouse main module.
+ */
+
+/*
+ * Copyright (C) 2010-2023 Oracle and/or its affiliates.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include <VBox/ExtPack/ExtPack.h>
+
+#include <iprt/errcore.h>
+#include <VBox/version.h>
+#include <iprt/string.h>
+#include <iprt/param.h>
+#include <iprt/path.h>
+
+
+/*********************************************************************************************************************************
+*   Global Variables                                                                                                             *
+*********************************************************************************************************************************/
+/** Pointer to the extension pack helpers. */
+static PCVBOXEXTPACKHLP g_pHlp;
+
+
+// /**
+//  * @interface_method_impl{VBOXEXTPACKREG,pfnInstalled}
+//  */
+// static DECLCALLBACK(void) vboxBusMouseExtPack_Installed(PCVBOXEXTPACKREG pThis, VBOXEXTPACK_IF_CS(IVirtualBox) *pVirtualBox, PRTERRINFO pErrInfo);
+//
+// /**
+//  * @interface_method_impl{VBOXEXTPACKREG,pfnUninstall}
+//  */
+// static DECLCALLBACK(int)  vboxBusMouseExtPack_Uninstall(PCVBOXEXTPACKREG pThis, VBOXEXTPACK_IF_CS(IVirtualBox) *pVirtualBox);
+//
+// /**
+//  * @interface_method_impl{VBOXEXTPACKREG,pfnVirtualBoxReady}
+//  */
+// static DECLCALLBACK(void)  vboxBusMouseExtPack_VirtualBoxReady(PCVBOXEXTPACKREG pThis, VBOXEXTPACK_IF_CS(IVirtualBox) *pVirtualBox);
+//
+// /**
+//  * @interface_method_impl{VBOXEXTPACKREG,pfnUnload}
+//  */
+// static DECLCALLBACK(void) vboxBusMouseExtPack_Unload(PCVBOXEXTPACKREG pThis);
+//
+// /**
+//  * @interface_method_impl{VBOXEXTPACKREG,pfnVMCreated}
+//  */
+// static DECLCALLBACK(int)  vboxBusMouseExtPack_VMCreated(PCVBOXEXTPACKREG pThis, VBOXEXTPACK_IF_CS(IVirtualBox) *pVirtualBox, VBOXEXTPACK_IF_CS(IMachine) *pMachine);
+//
+// /**
+//  * @interface_method_impl{VBOXEXTPACKREG,pfnQueryObject}
+//  */
+// static DECLCALLBACK(void) vboxBusMouseExtPack_QueryObject(PCVBOXEXTPACKREG pThis, PCRTUUID pObjectId);
+
+
+static const VBOXEXTPACKREG g_vboxBusMouseExtPackReg =
+{
+    VBOXEXTPACKREG_VERSION,
+    /* .uVBoxFullVersion =  */  VBOX_FULL_VERSION,
+    /* .pszNlsBaseName =    */  NULL,
+    /* .pfnInstalled =      */  NULL,
+    /* .pfnUninstall =      */  NULL,
+    /* .pfnVirtualBoxReady =*/  NULL,
+    /* .pfnUnload =         */  NULL,
+    /* .pfnVMCreated =      */  NULL,
+    /* .pfnQueryObject =    */  NULL,
+    /* .pfnReserved1 =      */  NULL,
+    /* .pfnReserved2 =      */  NULL,
+    /* .pfnReserved3 =      */  NULL,
+    /* .pfnReserved4 =      */  NULL,
+    /* .pfnReserved5 =      */  NULL,
+    /* .pfnReserved6 =      */  NULL,
+    /* .uReserved7 =        */  0,
+    VBOXEXTPACKREG_VERSION
+};
+
+
+/** @callback_method_impl{FNVBOXEXTPACKREGISTER}  */
+extern "C" DECLEXPORT(int) VBoxExtPackRegister(PCVBOXEXTPACKHLP pHlp, PCVBOXEXTPACKREG *ppReg, PRTERRINFO pErrInfo)
+{
+    /*
+     * Check the VirtualBox version.
+     */
+    if (!VBOXEXTPACK_IS_VER_COMPAT(pHlp->u32Version, VBOXEXTPACKHLP_VERSION))
+        return RTErrInfoSetF(pErrInfo, VERR_VERSION_MISMATCH,
+                             "Helper version mismatch - expected %#x got %#x",
+                             VBOXEXTPACKHLP_VERSION, pHlp->u32Version);
+    if (   VBOX_FULL_VERSION_GET_MAJOR(pHlp->uVBoxFullVersion) != VBOX_VERSION_MAJOR
+        || VBOX_FULL_VERSION_GET_MINOR(pHlp->uVBoxFullVersion) != VBOX_VERSION_MINOR)
+        return RTErrInfoSetF(pErrInfo, VERR_VERSION_MISMATCH,
+                             "VirtualBox version mismatch - expected %u.%u got %u.%u",
+                             VBOX_VERSION_MAJOR, VBOX_VERSION_MINOR,
+                             VBOX_FULL_VERSION_GET_MAJOR(pHlp->uVBoxFullVersion),
+                             VBOX_FULL_VERSION_GET_MINOR(pHlp->uVBoxFullVersion));
+
+    /*
+     * We're good, save input and return the registration structure.
+     */
+    g_pHlp = pHlp;
+    *ppReg = &g_vboxBusMouseExtPackReg;
+
+    return VINF_SUCCESS;
+}
+
diff --git a/src/VBox/ExtPacks/BusMouseSample/VBoxBusMouseMainVM.cpp b/src/VBox/ExtPacks/BusMouseSample/VBoxBusMouseMainVM.cpp
new file mode 100644
index 00000000..1f661a2f
--- /dev/null
+++ b/src/VBox/ExtPacks/BusMouseSample/VBoxBusMouseMainVM.cpp
@@ -0,0 +1,175 @@
+/* $Id: VBoxBusMouseMainVM.cpp $ */
+/** @file
+ * Bus Mouse main VM module.
+ */
+
+/*
+ * Copyright (C) 2010-2023 Oracle and/or its affiliates.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include <VBox/ExtPack/ExtPack.h>
+
+#include <VBox/err.h>
+#include <VBox/version.h>
+#include <VBox/vmm/vmmr3vtable.h>
+#include <iprt/string.h>
+#include <iprt/param.h>
+#include <iprt/path.h>
+
+
+/*********************************************************************************************************************************
+*   Global Variables                                                                                                             *
+*********************************************************************************************************************************/
+/** Pointer to the extension pack helpers. */
+static PCVBOXEXTPACKHLP g_pHlp;
+
+
+// /**
+//  * @interface_method_impl{VBOXEXTPACKVMREG,pfnConsoleReady}
+//  */
+// static DECLCALLBACK(void)  vboxBusMouseExtPackVM_ConsoleReady(PCVBOXEXTPACKVMREG pThis, VBOXEXTPACK_IF_CS(IConsole) *pConsole);
+//
+// /**
+//  * @interface_method_impl{VBOXEXTPACKVMREG,pfnUnload}
+//  */
+// static DECLCALLBACK(void) vboxBusMouseExtPackVM_Unload(PCVBOXEXTPACKVMREG pThis);
+
+/**
+ * @interface_method_impl{VBOXEXTPACKVMREG,pfnVMConfigureVMM
+ */
+static DECLCALLBACK(int)  vboxBusMouseExtPackVM_VMConfigureVMM(PCVBOXEXTPACKVMREG pThis, VBOXEXTPACK_IF_CS(IConsole) *pConsole,
+                                                               PVM pVM, PCVMMR3VTABLE pVMM)
+{
+    RT_NOREF(pThis, pConsole);
+
+    /*
+     * Find the bus mouse module and tell PDM to load it.
+     * ASSUME /PDM/Devices exists.
+     */
+    char szPath[RTPATH_MAX];
+    int rc = g_pHlp->pfnFindModule(g_pHlp, "VBoxBusMouseR3", NULL, VBOXEXTPACKMODKIND_R3, szPath, sizeof(szPath), NULL);
+    if (RT_FAILURE(rc))
+        return rc;
+
+    PCFGMNODE pCfgRoot = pVMM->pfnCFGMR3GetRoot(pVM);
+    AssertReturn(pCfgRoot, VERR_INTERNAL_ERROR_3);
+
+    PCFGMNODE pCfgDevices = pVMM->pfnCFGMR3GetChild(pCfgRoot, "PDM/Devices");
+    AssertReturn(pCfgDevices, VERR_INTERNAL_ERROR_3);
+
+    PCFGMNODE pCfgMine;
+    rc = pVMM->pfnCFGMR3InsertNode(pCfgDevices, "VBoxBusMouse", &pCfgMine);
+    AssertRCReturn(rc, rc);
+    rc = pVMM->pfnCFGMR3InsertString(pCfgMine, "Path", szPath);
+    AssertRCReturn(rc, rc);
+
+    /*
+     * Tell PDM where to find the R0 and RC modules for the bus mouse device.
+     */
+#ifdef VBOX_WITH_RAW_MODE
+    rc = g_pHlp->pfnFindModule(g_pHlp, "VBoxBusMouseRC", NULL, VBOXEXTPACKMODKIND_RC, szPath, sizeof(szPath), NULL);
+    AssertRCReturn(rc, rc);
+    RTPathStripFilename(szPath);
+    rc = pVMM->pfnCFGMR3InsertString(pCfgMine, "RCSearchPath", szPath);
+    AssertRCReturn(rc, rc);
+#endif
+
+    rc = g_pHlp->pfnFindModule(g_pHlp, "VBoxBusMouseR0", NULL, VBOXEXTPACKMODKIND_R0, szPath, sizeof(szPath), NULL);
+    AssertRCReturn(rc, rc);
+    RTPathStripFilename(szPath);
+    rc = pVMM->pfnCFGMR3InsertString(pCfgMine, "R0SearchPath", szPath);
+    AssertRCReturn(rc, rc);
+
+    return VINF_SUCCESS;
+}
+
+// /**
+//  * @interface_method_impl{VBOXEXTPACKVMREG,pfnVMPowerOn}
+//  */
+// static DECLCALLBACK(int)  vboxBusMouseExtPackVM_VMPowerOn(PCVBOXEXTPACKVMREG pThis, VBOXEXTPACK_IF_CS(IConsole) *pConsole, PVM pVM);
+//
+// /**
+//  * @interface_method_impl{VBOXEXTPACKVMREG,pfnVMPowerOff}
+//  */
+// static DECLCALLBACK(void) vboxBusMouseExtPackVM_VMPowerOff(PCVBOXEXTPACKVMREG pThis, VBOXEXTPACK_IF_CS(IConsole) *pConsole, PVM pVM);
+//
+// /**
+//  * @interface_method_impl{VBOXEXTPACKVMREG,pfnQueryObject}
+//  */
+// static DECLCALLBACK(void) vboxBusMouseExtPackVM_QueryObject(PCVBOXEXTPACKVMREG pThis, PCRTUUID pObjectId);
+
+
+static const VBOXEXTPACKVMREG g_vboxBusMouseExtPackVMReg =
+{
+    VBOXEXTPACKVMREG_VERSION,
+    /* .uVBoxFullVersion =  */  VBOX_FULL_VERSION,
+    /* .pszNlsBaseName =    */  NULL,
+    /* .pfnConsoleReady =   */  NULL,
+    /* .pfnUnload =         */  NULL,
+    /* .pfnVMConfigureVMM = */  vboxBusMouseExtPackVM_VMConfigureVMM,
+    /* .pfnVMPowerOn =      */  NULL,
+    /* .pfnVMPowerOff =     */  NULL,
+    /* .pfnQueryObject =    */  NULL,
+    /* .pfnReserved1 =      */  NULL,
+    /* .pfnReserved2 =      */  NULL,
+    /* .pfnReserved3 =      */  NULL,
+    /* .pfnReserved4 =      */  NULL,
+    /* .pfnReserved5 =      */  NULL,
+    /* .pfnReserved6 =      */  NULL,
+    /* .uReserved7 =        */  0,
+    VBOXEXTPACKVMREG_VERSION
+};
+
+
+/** @callback_method_impl{FNVBOXEXTPACKVMREGISTER}  */
+extern "C" DECLEXPORT(int) VBoxExtPackVMRegister(PCVBOXEXTPACKHLP pHlp, PCVBOXEXTPACKVMREG *ppReg, PRTERRINFO pErrInfo)
+{
+    /*
+     * Check the VirtualBox version.
+     */
+    if (!VBOXEXTPACK_IS_VER_COMPAT(pHlp->u32Version, VBOXEXTPACKHLP_VERSION))
+        return RTErrInfoSetF(pErrInfo, VERR_VERSION_MISMATCH,
+                             "Helper version mismatch - expected %#x got %#x",
+                             VBOXEXTPACKHLP_VERSION, pHlp->u32Version);
+    if (   VBOX_FULL_VERSION_GET_MAJOR(pHlp->uVBoxFullVersion) != VBOX_VERSION_MAJOR
+        || VBOX_FULL_VERSION_GET_MINOR(pHlp->uVBoxFullVersion) != VBOX_VERSION_MINOR)
+        return RTErrInfoSetF(pErrInfo, VERR_VERSION_MISMATCH,
+                             "VirtualBox version mismatch - expected %u.%u got %u.%u",
+                             VBOX_VERSION_MAJOR, VBOX_VERSION_MINOR,
+                             VBOX_FULL_VERSION_GET_MAJOR(pHlp->uVBoxFullVersion),
+                             VBOX_FULL_VERSION_GET_MINOR(pHlp->uVBoxFullVersion));
+
+    /*
+     * We're good, save input and return the registration structure.
+     */
+    g_pHlp = pHlp;
+    *ppReg = &g_vboxBusMouseExtPackVMReg;
+
+    return VINF_SUCCESS;
+}
+