reactos/drivers/storage/class/ramdisk/ramdisk.c

/*
 * PROJECT:         Ramdisk Class Driver
 * LICENSE:         BSD - See COPYING.ARM in the top level directory
 * FILE:            drivers/storage/class/ramdisk/ramdisk.c
 * PURPOSE:         Main Driver Routines
 * PROGRAMMERS:     ReactOS Portable Systems Group
 */

/* INCLUDES *******************************************************************/

#include <initguid.h>
#include <ntddk.h>
#include <ntdddisk.h>
#include <ntddcdrm.h>
#include <scsi.h>
#include <ntddscsi.h>
#include <ntddvol.h>
#include <mountdev.h>
#include <mountmgr.h>
#include <ketypes.h>
#include <iotypes.h>
#include <rtlfuncs.h>
#include <arc/arc.h>
#include <reactos/drivers/ntddrdsk.h>
#include "../../../filesystems/fs_rec/fs_rec.h"
#include <stdio.h>
#define NDEBUG
#include <debug.h>

/* GLOBALS ********************************************************************/

#define RAMDISK_SESSION_SIZE \
    FIELD_OFFSET(CDROM_TOC, TrackData) + sizeof(TRACK_DATA)
    
#define RAMDISK_TOC_SIZE \
    FIELD_OFFSET(CDROM_TOC, TrackData) + 2 * sizeof(TRACK_DATA)
                                    
#define TOC_DATA_TRACK              (0x04)

typedef enum _RAMDISK_DEVICE_TYPE
{
    RamdiskBus,
    RamdiskDrive
} RAMDISK_DEVICE_TYPE;

typedef enum _RAMDISK_DEVICE_STATE
{
    RamdiskStateUninitialized,
    RamdiskStateStarted,
    RamdiskStatePaused,
    RamdiskStateStopped,
    RamdiskStateRemoved,
    RamdiskStateBusRemoved,
    RamdiskStateEnumerated,
} RAMDISK_DEVICE_STATE;

DEFINE_GUID(RamdiskBusInterface,
		    0x5DC52DF0,
			0x2F8A,
			0x410F,
			0x80, 0xE4, 0x05, 0xF8, 0x10, 0xE7, 0xA8, 0x8A);

typedef struct _RAMDISK_EXTENSION
{
    RAMDISK_DEVICE_TYPE Type;
    RAMDISK_DEVICE_STATE State;
    PDEVICE_OBJECT DeviceObject;
    PDEVICE_OBJECT PhysicalDeviceObject;
    PDEVICE_OBJECT AttachedDevice;
    IO_REMOVE_LOCK RemoveLock;
    UNICODE_STRING DriveDeviceName;
    UNICODE_STRING BusDeviceName;
    FAST_MUTEX DiskListLock;
    LIST_ENTRY DiskList;
} RAMDISK_EXTENSION, *PRAMDISK_EXTENSION;

typedef struct _RAMDISK_BUS_EXTENSION
{
    RAMDISK_EXTENSION;
} RAMDISK_BUS_EXTENSION, *PRAMDISK_BUS_EXTENSION;

typedef struct _RAMDISK_DRIVE_EXTENSION
{
    //
    // Inherited base class
    //
    RAMDISK_EXTENSION;
    
    //
    // Data we get from the creator
    //
    GUID DiskGuid;
    UNICODE_STRING GuidString;
    UNICODE_STRING SymbolicLinkName;
    ULONG DiskType;
    RAMDISK_CREATE_OPTIONS DiskOptions;
    LARGE_INTEGER DiskLength;
    LONG DiskOffset;
    WCHAR DriveLetter;
    ULONG BasePage;
    
    //
    // Data we get from the disk
    //
    ULONG BytesPerSector;
    ULONG SectorsPerTrack;
    ULONG NumberOfHeads;
    ULONG Cylinders;
    ULONG HiddenSectors;
} RAMDISK_DRIVE_EXTENSION, *PRAMDISK_DRIVE_EXTENSION;

ULONG MaximumViewLength;
ULONG MaximumPerDiskViewLength;
ULONG ReportDetectedDevice;
ULONG MarkRamdisksAsRemovable;
ULONG MinimumViewCount;
ULONG DefaultViewCount;
ULONG MaximumViewCount;
ULONG MinimumViewLength;
ULONG DefaultViewLength;
UNICODE_STRING DriverRegistryPath;
BOOLEAN ExportBootDiskAsCd;
BOOLEAN IsWinPEBoot;
PDEVICE_OBJECT RamdiskBusFdo;

/* FUNCTIONS ******************************************************************/

VOID
NTAPI
QueryParameters(IN PUNICODE_STRING RegistryPath)
{
    ULONG MinView, DefView, MinViewLength, DefViewLength, MaxViewLength;
    RTL_QUERY_REGISTRY_TABLE QueryTable[10];
    
    //
    // Set defaults
    //
    MaximumViewLength = 0x10000000u;
    MaximumPerDiskViewLength = 0x10000000u;
    ReportDetectedDevice = 0;
    MarkRamdisksAsRemovable = 0;
    MinimumViewCount = 2;
    DefaultViewCount = 16;
    MaximumViewCount = 64;
    MinimumViewLength = 0x10000u;
    DefaultViewLength = 0x100000u;
    
    //
    // Setup the query table and query the registry
    //
    RtlZeroMemory(QueryTable, sizeof(QueryTable));
    QueryTable[0].Flags = 1;
    QueryTable[0].Name = L"Parameters";
    QueryTable[1].Flags = 32;
    QueryTable[1].Name = L"ReportDetectedDevice";
    QueryTable[1].EntryContext = &ReportDetectedDevice;
    QueryTable[2].Flags = 32;
    QueryTable[2].Name = L"MarkRamdisksAsRemovable";
    QueryTable[2].EntryContext = &MarkRamdisksAsRemovable;
    QueryTable[3].Flags = 32;
    QueryTable[3].Name = L"MinimumViewCount";
    QueryTable[3].EntryContext = &MinimumViewCount;
    QueryTable[4].Flags = 32;
    QueryTable[4].Name = L"DefaultViewCount";
    QueryTable[4].EntryContext = &DefaultViewCount;
    QueryTable[5].Flags = 32;
    QueryTable[5].Name = L"MaximumViewCount";
    QueryTable[5].EntryContext = &MaximumViewCount;
    QueryTable[6].Flags = 32;
    QueryTable[6].Name = L"MinimumViewLength";
    QueryTable[6].EntryContext = &MinimumViewLength;
    QueryTable[7].Flags = 32;
    QueryTable[7].Name = L"DefaultViewLength";
    QueryTable[7].EntryContext = &DefaultViewLength;
    QueryTable[8].Flags = 32;
    QueryTable[8].Name = L"MaximumViewLength";
    QueryTable[8].EntryContext = &MaximumViewLength;
    QueryTable[9].Flags = 32;
    QueryTable[9].Name = L"MaximumPerDiskViewLength";
    QueryTable[9].EntryContext = &MaximumPerDiskViewLength;
    RtlQueryRegistryValues(RTL_REGISTRY_OPTIONAL,
                           RegistryPath->Buffer,
                           QueryTable,
                           NULL,
                           NULL);
    
    //
    // Parse minimum view count, cannot be bigger than 256 or smaller than 2
    //
    MinView = MinimumViewCount;
    if (MinimumViewCount >= 2)
    {
        if (MinimumViewCount > 256) MinView = 256;
    }
    else
    {
        MinView = 2;
    }
    MinimumViewCount = MinView;

    //
    // Parse default view count, cannot be bigger than 256 or smaller than minimum
    //
    DefView = DefaultViewCount;
    if (DefaultViewCount >= MinView)
    {
        if (DefaultViewCount > 256) DefView = 256;
    }
    else
    {
        DefView = MinView;
    }
    DefaultViewCount = DefView;
    
    //
    // Parse maximum view count, cannot be bigger than 256 or smaller than default
    //
    if (MaximumViewCount >= DefView)
    {
        if (MaximumViewCount > 256) MaximumViewCount = 256;
    }
    else
    {
        MaximumViewCount = DefView;
    }
    
    //
    // Parse minimum view length, cannot be bigger than 1GB or smaller than 64KB
    //
    MinViewLength = MinimumViewLength;
    if (MinimumViewLength >= 0x10000)
    {
        if (MinimumViewLength > 0x40000000) MinViewLength = 0x40000000u;
    }
    else
    {
        MinViewLength = 0x10000u;
    }
    MinimumViewLength = MinViewLength;

    //
    // Parse default view length, cannot be bigger than 1GB or smaller than minimum
    //
    DefViewLength = DefaultViewLength;
    if (DefaultViewLength >= MinViewLength)
    {
        if (DefaultViewLength > 0x40000000) DefViewLength = 0x40000000u;
    }
    else
    {
        DefViewLength = MinViewLength;
    }
    DefaultViewLength = DefViewLength;

    //
    // Parse maximum view length, cannot be bigger than 1GB or smaller than default
    //
    MaxViewLength = MaximumViewLength;
    if (MaximumViewLength >= DefViewLength)
    {
        if (MaximumViewLength > 0x40000000) MaxViewLength = 0x40000000u;
    }
    else
    {
        MaxViewLength = DefViewLength;
    }
    MaximumViewLength = MaxViewLength;

    //
    // Parse maximum view length per disk, cannot be smaller than 16MB
    //
    if (MaximumPerDiskViewLength >= 0x1000000)
    {
        if (MaxViewLength > 0xFFFFFFFF) MaximumPerDiskViewLength = -1;
    }
    else
    {
        MaximumPerDiskViewLength = 0x1000000u;
    }
}

PVOID
NTAPI
RamdiskMapPages(IN PRAMDISK_DRIVE_EXTENSION DeviceExtension,
                IN LARGE_INTEGER Offset,
                IN ULONG Length,
                OUT PULONG OutputLength)
{
    PHYSICAL_ADDRESS PhysicalAddress;
    PVOID MappedBase;
    ULONG PageOffset;
    SIZE_T ActualLength;
    LARGE_INTEGER ActualOffset;
    LARGE_INTEGER ActualPages;
    
    //
    // We only support boot disks for now
    //
    ASSERT(DeviceExtension->DiskType == RAMDISK_BOOT_DISK);
    
    //
    // Calculate the actual offset in the drive
    //
    ActualOffset.QuadPart = DeviceExtension->DiskOffset + Offset.QuadPart;
    
    //
    // Convert to pages
    //
    ActualPages.QuadPart = ActualOffset.QuadPart >> PAGE_SHIFT;
    
    //
    // Now add the base page
    //
    ActualPages.QuadPart = DeviceExtension->BasePage + ActualPages.QuadPart;
    
    //
    // Calculate final amount of bytes
    //
    PhysicalAddress.QuadPart = ActualPages.QuadPart << PAGE_SHIFT;
    
    //
    // Calculate pages spanned for the mapping
    //
    ActualLength = ADDRESS_AND_SIZE_TO_SPAN_PAGES(ActualOffset.QuadPart, Length);
    
    //
    // And convert this back to bytes
    //
    ActualLength <<= PAGE_SHIFT;
    
    //
    // Get the offset within the page
    //
    PageOffset = BYTE_OFFSET(ActualOffset.QuadPart);
    
    //
    // Map the I/O Space from the loader
    //
    MappedBase = MmMapIoSpace(PhysicalAddress, ActualLength, MmCached);
    
    //
    // Return actual offset within the page as well as the length
    //
    if (MappedBase) MappedBase = (PVOID)((ULONG_PTR)MappedBase + PageOffset);
    *OutputLength = Length;
    return MappedBase;
}

VOID
NTAPI
RamdiskUnmapPages(IN PRAMDISK_DRIVE_EXTENSION DeviceExtension,
                  IN PVOID BaseAddress,
                  IN LARGE_INTEGER Offset,
                  IN ULONG Length)
{
    LARGE_INTEGER ActualOffset;
    SIZE_T ActualLength;
    ULONG PageOffset;
    
    //
    // We only support boot disks for now
    //
    ASSERT(DeviceExtension->DiskType == RAMDISK_BOOT_DISK);
    
    //
    // Calculate the actual offset in the drive
    //
    ActualOffset.QuadPart = DeviceExtension->DiskOffset + Offset.QuadPart;
    
    //
    // Calculate pages spanned for the mapping
    //
    ActualLength = ADDRESS_AND_SIZE_TO_SPAN_PAGES(ActualOffset.QuadPart, Length);
    
    //
    // And convert this back to bytes
    //
    ActualLength <<= PAGE_SHIFT;
    
    //
    // Get the offset within the page
    //
    PageOffset = BYTE_OFFSET(ActualOffset.QuadPart);
    
    //
    // Calculate actual base address where we mapped this
    //
    BaseAddress = (PVOID)((ULONG_PTR)BaseAddress - PageOffset);
    
    //
    // Unmap the I/O space we got from the loader
    //
    MmUnmapIoSpace(BaseAddress, ActualLength);
}

NTSTATUS
NTAPI
RamdiskCreateDiskDevice(IN PRAMDISK_BUS_EXTENSION DeviceExtension,
						IN PRAMDISK_CREATE_INPUT Input,
						IN BOOLEAN ValidateOnly,
						OUT PRAMDISK_DRIVE_EXTENSION *NewDriveExtension)
{
	ULONG BasePage, ViewCount, DiskType, Length;
    NTSTATUS Status;
    PDEVICE_OBJECT DeviceObject;
    PRAMDISK_DRIVE_EXTENSION DriveExtension;
    PVOID Buffer;
    WCHAR LocalBuffer[16];
    UNICODE_STRING SymbolicLinkName, DriveString, GuidString, DeviceName;
    PPACKED_BOOT_SECTOR BootSector;
    BIOS_PARAMETER_BLOCK BiosBlock;
    ULONG BytesPerSector, SectorsPerTrack, Heads, BytesRead;
    PVOID BaseAddress;
    LARGE_INTEGER CurrentOffset, CylinderSize, DiskLength;
    ULONG CylinderCount, SizeByCylinders;
	
	//
	// Check if we're a boot RAM disk
	//
	DiskType = Input->DiskType;
	if (DiskType >= RAMDISK_BOOT_DISK)
	{
		//
		// Check if we're an ISO
		// 
		if (DiskType == RAMDISK_BOOT_DISK)
		{
			//
			// NTLDR mounted us somewhere
			//
			BasePage = Input->BasePage;
			if (!BasePage) return STATUS_INVALID_PARAMETER;
			
			//
			// Sanitize disk options
			//
			Input->Options.Fixed = TRUE;
			Input->Options.Readonly = Input->Options.ExportAsCd |
                                      Input->Options.Readonly;
			Input->Options.Hidden = FALSE;
			Input->Options.NoDosDevice = FALSE;
			Input->Options.NoDriveLetter = IsWinPEBoot ? TRUE : FALSE;
		}
		else
		{
			//
			// The only other possibility is a WIM disk
			//
			if (DiskType != RAMDISK_WIM_DISK)
            {
                //
                // Fail
                //
                return STATUS_INVALID_PARAMETER;
            }
			
			//
			// Read the view count instead
			//
			ViewCount = Input->ViewCount;
			
			//
			// Sanitize disk options
			//
			Input->Options.Hidden = FALSE;
			Input->Options.NoDosDevice = FALSE;
			Input->Options.Readonly = FALSE;
			Input->Options.NoDriveLetter = TRUE;
			Input->Options.Fixed = TRUE;
		}
		
		//
		// Are we just validating and returning to the user?
		//
		if (ValidateOnly) return STATUS_SUCCESS;
        
        //
        // Build the GUID string
        //
        Status = RtlStringFromGUID(&Input->DiskGuid, &GuidString);
        if (!(NT_SUCCESS(Status)) || !(GuidString.Buffer))
        {
            //
            // Fail
            //
            Status = STATUS_INSUFFICIENT_RESOURCES;
            goto FailCreate;
        }
        
        //
        // Allocate our device name
        //
        Length = GuidString.Length + 32;
        Buffer = ExAllocatePoolWithTag(NonPagedPool,
                                       Length,
                                       'dmaR');
        if (!Buffer)
        {
            //
            // Fail
            //
            Status = STATUS_INSUFFICIENT_RESOURCES;
            goto FailCreate;
        }
        
        // 
        // Build the device name string
        //
        DeviceName.Buffer = Buffer;
        DeviceName.Length = Length - 2;
        DeviceName.MaximumLength = Length;
        wcsncpy(Buffer, L"\\Device\\Ramdisk", Length / sizeof(WCHAR));
        wcsncat(Buffer, GuidString.Buffer, Length / sizeof(WCHAR));
        
        //
        // Create the drive device
        //
        Status = IoCreateDevice(DeviceExtension->DeviceObject->DriverObject,
                                sizeof(RAMDISK_DRIVE_EXTENSION),
                                &DeviceName,
                                (Input->Options.ExportAsCd) ?
                                FILE_DEVICE_CD_ROM : FILE_DEVICE_DISK,
                                0,
                                0,
                                &DeviceObject);
        if (!NT_SUCCESS(Status)) goto FailCreate;
        
        //
        // Grab the drive extension
        //
        DriveExtension = DeviceObject->DeviceExtension;
       
        //
        // Check if we need a DOS device
        //
        if (!Input->Options.NoDosDevice)
        {
            //
            // Build the symbolic link name
            //
            SymbolicLinkName.MaximumLength = GuidString.Length + 36;
            SymbolicLinkName.Length = GuidString.Length + 34;
            Buffer = ExAllocatePoolWithTag(NonPagedPool,
                                           SymbolicLinkName.MaximumLength,
                                           'dmaR');
            SymbolicLinkName.Buffer = Buffer;
            if (Buffer)
            {
                //
                // Create it
                //
                wcsncpy(Buffer,
                        L"\\GLOBAL??\\Ramdisk",
                        SymbolicLinkName.MaximumLength / sizeof(WCHAR));
                wcsncat(Buffer,
                        GuidString.Buffer,
                        SymbolicLinkName.MaximumLength / sizeof(WCHAR));
                Status = IoCreateSymbolicLink(&SymbolicLinkName, &DeviceName);
                if (!NT_SUCCESS(Status))
                {
                    //
                    // Nevermind...
                    //
                    Input->Options.NoDosDevice = TRUE;
                    ExFreePool(Buffer);
                    SymbolicLinkName.Buffer = NULL;
                }
            }
            else
            {
                //
                // No DOS device
                //
                Input->Options.NoDosDevice = TRUE;
            }
            
            //
            // It this an ISO boot ramdisk?
            //
            if (Input->DiskType == RAMDISK_BOOT_DISK)
            {
                //
                // Does it need a drive letter?
                //
                if (!Input->Options.NoDriveLetter)
                {
                    //
                    // Build it and take over the existing symbolic link
                    //
                    _snwprintf(LocalBuffer,
                               30,
                               L"\\DosDevices\\%wc:",
                               Input->DriveLetter);
                    RtlInitUnicodeString(&DriveString, LocalBuffer);
                    IoDeleteSymbolicLink(&DriveString);
                    IoCreateSymbolicLink(&DriveString, &DeviceName);
                    
                    //
                    // Save the drive letter
                    //
                    DriveExtension->DriveLetter = Input->DriveLetter;
                }
            }
            
        }
        
        //
        // Setup the device object flags
        //
        DeviceObject->Flags |= (DO_XIP | DO_POWER_PAGABLE | DO_DIRECT_IO);
        DeviceObject->AlignmentRequirement = 1;
        
        //
        // Build the drive FDO
        //
        *NewDriveExtension = DriveExtension;
        DriveExtension->Type = RamdiskDrive;
        DiskLength = Input->DiskLength;
		ExInitializeFastMutex(&DriveExtension->DiskListLock);
	    IoInitializeRemoveLock(&DriveExtension->RemoveLock,
                               'dmaR',
                               0,
                               1);
        DriveExtension->DriveDeviceName = DeviceName;
        DriveExtension->SymbolicLinkName = SymbolicLinkName;
        DriveExtension->GuidString = GuidString;
        DriveExtension->DiskGuid = Input->DiskGuid;
	    DriveExtension->PhysicalDeviceObject = DeviceObject;
	    DriveExtension->DeviceObject = RamdiskBusFdo;
        DriveExtension->AttachedDevice = RamdiskBusFdo;
        DriveExtension->DiskType = Input->DiskType;
        DriveExtension->DiskOptions = Input->Options;
        DriveExtension->DiskLength = DiskLength;
        DriveExtension->DiskOffset = Input->DiskOffset;
        DriveExtension->BasePage = Input->BasePage;
        DriveExtension->BytesPerSector = 0;
        DriveExtension->SectorsPerTrack = 0;
        DriveExtension->NumberOfHeads = 0;
        
        //
        // Make sure we don't free it later
        //
        DeviceName.Buffer = NULL;
        SymbolicLinkName.Buffer = NULL;
        GuidString.Buffer = NULL;
        
        //
        // Check if this is an boot disk, or a registry ram drive
        //
        if (!(Input->Options.ExportAsCd) &&
            (Input->DiskType == RAMDISK_BOOT_DISK))
        {
            //
            // Not an ISO boot, but it's a boot FS -- map it to figure out the
            // drive settings
            //
            CurrentOffset.QuadPart = 0;
            BaseAddress = RamdiskMapPages(DriveExtension,
                                          CurrentOffset,
                                          PAGE_SIZE,
                                          &BytesRead);
            if (BaseAddress)
            {
                //
                // Get the data
                //
                BootSector = (PPACKED_BOOT_SECTOR)BaseAddress;
                FatUnpackBios(&BiosBlock, &BootSector->PackedBpb);
                BytesPerSector = BiosBlock.BytesPerSector;
                SectorsPerTrack = BiosBlock.SectorsPerTrack;
                Heads = BiosBlock.Heads;
                
                //
                // Save it
                //
                DriveExtension->BytesPerSector = BytesPerSector;
                DriveExtension->SectorsPerTrack = SectorsPerTrack;
                DriveExtension->NumberOfHeads = Heads;
                
                //
                // Unmap now
                //
                CurrentOffset.QuadPart = 0;
                RamdiskUnmapPages(DriveExtension,
                                  BaseAddress,
                                  CurrentOffset,
                                  BytesRead);
            }
            else
            {
                //
                // Fail
                //
                Status = STATUS_INSUFFICIENT_RESOURCES;
                goto FailCreate;
            }
        }
                
        //
        // Check if the drive settings haven't been set yet
        //
        if ((DriveExtension->BytesPerSector == 0) ||
            (DriveExtension->SectorsPerTrack == 0) ||
            (DriveExtension->NumberOfHeads == 0))
        {
            //
            // Check if this is a CD
            //
            if (Input->Options.ExportAsCd)
            {
                //
                // Setup partition parameters default for ISO 9660
                //
                DriveExtension->BytesPerSector = 2048;
                DriveExtension->SectorsPerTrack = 32;
                DriveExtension->NumberOfHeads = 64;
            }
            else
            {
                //
                // Setup partition parameters default for FAT
                //
                DriveExtension->BytesPerSector = 512;
                DriveExtension->SectorsPerTrack = 128;
                DriveExtension->NumberOfHeads = 16;
            }
        }
        
        //
        // Calculate the cylinder size
        //
        CylinderSize.QuadPart = DriveExtension->BytesPerSector *
                                DriveExtension->SectorsPerTrack *
                                DriveExtension->NumberOfHeads;
        CylinderCount = DiskLength.QuadPart / CylinderSize.QuadPart;
        SizeByCylinders = CylinderSize.QuadPart * CylinderCount;
        DriveExtension->Cylinders = CylinderCount;
        if ((DiskLength.HighPart > 0) || (SizeByCylinders < DiskLength.LowPart))
        {
            //
            // Align cylinder size up
            //
            DriveExtension->Cylinders++;
        }
        
        //
        // Acquire the disk lock
        //
        KeEnterCriticalRegion();
        ExAcquireFastMutex(&DeviceExtension->DiskListLock);
        
        //
        // Insert us
        //
        InsertTailList(&DeviceExtension->DiskList, &DriveExtension->DiskList);
        
        //
        // Release the lock
        //
        ExReleaseFastMutex(&DeviceExtension->DiskListLock);
        KeLeaveCriticalRegion();
        
        //
        // Clear init flag
        //
        DeviceObject->Flags &= ~DO_DEVICE_INITIALIZING;
        return STATUS_SUCCESS;
    }
    
FailCreate:
    UNIMPLEMENTED;
    while (TRUE);
    return STATUS_SUCCESS;
}

NTSTATUS
NTAPI
RamdiskCreateRamdisk(IN PDEVICE_OBJECT DeviceObject,
                     IN PIRP Irp,
					 IN BOOLEAN ValidateOnly)
{
	PRAMDISK_CREATE_INPUT Input;
	ULONG Length;
	PRAMDISK_BUS_EXTENSION DeviceExtension;
    PRAMDISK_DRIVE_EXTENSION DriveExtension; 
	ULONG DiskType;
	PWCHAR FileNameStart, FileNameEnd;
	NTSTATUS Status;
	PIO_STACK_LOCATION IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
	
	//
	// Get the device extension and our input data
	//
	DeviceExtension = DeviceObject->DeviceExtension;
	Length = IoStackLocation->Parameters.DeviceIoControl.InputBufferLength;
	Input = (PRAMDISK_CREATE_INPUT)Irp->AssociatedIrp.SystemBuffer;
	
	//
	// Validate input parameters
	//
	if ((Length < sizeof(RAMDISK_CREATE_INPUT)) ||
		(Input->Version != sizeof(RAMDISK_CREATE_INPUT)))
	{
		//
		// Invalid input
		//
		return STATUS_INVALID_PARAMETER;
	}
	
	//
	// Validate the disk type
	//
	DiskType = Input->DiskType;
	if (DiskType == RAMDISK_WIM_DISK) return STATUS_INVALID_PARAMETER;
	
	//
	// Look at the disk type
	//
	if (DiskType == RAMDISK_BOOT_DISK)
	{
		//
		// We only allow this as an early-init boot
		//
		if (!KeLoaderBlock) return STATUS_INVALID_PARAMETER;
		
		//
		// Save command-line flags
		//
		if (ExportBootDiskAsCd) Input->Options.ExportAsCd = TRUE;
		if (IsWinPEBoot) Input->Options.NoDriveLetter = TRUE;
	}
    
	//
	// Validate the disk type
	//
	if ((Input->Options.ExportAsCd) && (DiskType != RAMDISK_BOOT_DISK))
	{
		//
		// If the type isn't CDFS, it has to at least be raw CD
		//
		if (DiskType != RAMDISK_MEMORY_MAPPED_DISK) return STATUS_INVALID_PARAMETER;
	}
	
	//
	// Check if this is an actual file
	//
	if (DiskType <= RAMDISK_MEMORY_MAPPED_DISK)
	{
		//
		// Validate the file name
		//
		FileNameStart = (PWCHAR)((ULONG_PTR)Input + Length);
		FileNameEnd = Input->FileName + 1;
		while ((FileNameEnd < FileNameStart) && *(FileNameEnd)) FileNameEnd++;
		if (FileNameEnd == FileNameStart) return STATUS_INVALID_PARAMETER;
	}
    
	//
	// Create the actual device
	//
	Status = RamdiskCreateDiskDevice(DeviceExtension,
									 Input, 
									 ValidateOnly,
									 &DriveExtension);
	if (NT_SUCCESS(Status))
	{
		//
		// Invalidate and set success
		//
		IoInvalidateDeviceRelations(DeviceExtension->PhysicalDeviceObject, 0);
		Irp->IoStatus.Information = STATUS_SUCCESS;
	}
	
	//
	// We're done
	//
	return Status;
}

VOID
NTAPI
RamdiskWorkerThread(IN PDEVICE_OBJECT DeviceObject,
                    IN PVOID Context)
{
    PRAMDISK_BUS_EXTENSION DeviceExtension;
    NTSTATUS Status;
    PIO_STACK_LOCATION IoStackLocation;
    PIRP Irp = Context;
    
    //
    // Get the stack location
    //
    IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
    
    //
    // Free the work item
    //
    IoFreeWorkItem(Irp->Tail.Overlay.DriverContext[0]);
    
    //
    // Grab the device extension and lock it
    //
    DeviceExtension = DeviceObject->DeviceExtension;
    Status = IoAcquireRemoveLock(&DeviceExtension->RemoveLock, Irp);
    if (NT_SUCCESS(Status))
    {
        //
        // Discriminate by major code
        //
        switch (IoStackLocation->MajorFunction)
        {
            //
            // Device control
            //
            case IRP_MJ_DEVICE_CONTROL:
                               
                //
                // Let's take a look at the IOCTL
                //
                switch (IoStackLocation->Parameters.DeviceIoControl.IoControlCode)
                {
                    //
                    // Ramdisk create request
                    //
                    case FSCTL_CREATE_RAM_DISK:
                        
                        //
                        // This time we'll do it for real
                        //
                        Status = RamdiskCreateRamdisk(DeviceObject, Irp, FALSE);
                        break;
                        
                    case IOCTL_DISK_SET_PARTITION_INFO:
                        
                        DPRINT1("Set partition info request\n");
                        UNIMPLEMENTED;
                        while (TRUE);
                        break;
                        
                    case IOCTL_DISK_GET_DRIVE_LAYOUT:
                        
                        DPRINT1("Get drive layout request\n");
                        UNIMPLEMENTED;
                        while (TRUE);
                        break;
                        
                    case IOCTL_DISK_GET_PARTITION_INFO:
                        
                        DPRINT1("Get partitinon info request\n");
                        UNIMPLEMENTED;
                        while (TRUE);
                        break;
                        
                    default:
                        
                        DPRINT1("Invalid request\n");
                        UNIMPLEMENTED;
                        while (TRUE);
                        break;
                }
                
                //
                // We're  here
                //
                break;
                
            //
            // Read or write request
            //
            case IRP_MJ_READ:
            case IRP_MJ_WRITE:
                
                DPRINT1("Read/Write request\n");
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            //
            // Internal request (SCSI?)
            //
            case IRP_MJ_INTERNAL_DEVICE_CONTROL:

                DPRINT1("SCSI request\n");
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            //
            // Flush request
            //
            case IRP_MJ_FLUSH_BUFFERS:
                
                DPRINT1("Flush request\n");
                UNIMPLEMENTED;
                while (TRUE);
                break;

            //
            // Anything else
            //
            default:
                
                DPRINT1("Invalid request: %lx\n", IoStackLocation->MajorFunction);
                UNIMPLEMENTED;
                while (TRUE);
                break;
        }
        
        //
        // Complete the I/O
        //
        IoReleaseRemoveLock(&DeviceExtension->RemoveLock, Irp);
        Irp->IoStatus.Status = Status;
        Irp->IoStatus.Information = 0;
        IoCompleteRequest(Irp, IO_DISK_INCREMENT);
        return;
    }
    
    //
    // Fail the I/O
    //
    Irp->IoStatus.Status = Status;
    Irp->IoStatus.Information = 0;
    IoCompleteRequest(Irp, IO_NO_INCREMENT);
}

NTSTATUS
NTAPI
SendIrpToThread(IN PDEVICE_OBJECT DeviceObject,
                IN PIRP Irp)
{
    PIO_WORKITEM WorkItem;
    
    //
    // Mark the IRP pending
    //
    IoMarkIrpPending(Irp);
    
    //
    // Allocate a work item
    //
    WorkItem = IoAllocateWorkItem(DeviceObject);
    if (WorkItem)
    {
        //
        // Queue it up
        //
        Irp->Tail.Overlay.DriverContext[0] = WorkItem;
        IoQueueWorkItem(WorkItem, RamdiskWorkerThread, DelayedWorkQueue, Irp);
        return STATUS_PENDING;
    }
    else
    {
        //
        // Fail
        //
        return STATUS_INSUFFICIENT_RESOURCES;
    }
}

NTSTATUS
NTAPI
RamdiskReadWriteReal(IN PIRP Irp,
                     IN PRAMDISK_DRIVE_EXTENSION DeviceExtension)
{
    PMDL Mdl;
    PVOID CurrentBase, SystemVa, BaseAddress;
    PIO_STACK_LOCATION IoStackLocation;
    LARGE_INTEGER CurrentOffset;
    ULONG BytesRead, BytesLeft, CopyLength;
    PVOID Source, Destination;
    NTSTATUS Status;
    
    //
    // Get the MDL and check if it's mapped
    //
    Mdl = Irp->MdlAddress;
    if (Mdl->MdlFlags & (MDL_MAPPED_TO_SYSTEM_VA | MDL_SOURCE_IS_NONPAGED_POOL))
    {
        //
        // Use the mapped address
        //
        SystemVa = Mdl->MappedSystemVa;
    }
    else
    {
        //
        // Map it ourselves
        //
        SystemVa = MmMapLockedPagesSpecifyCache(Mdl,
                                                0,
                                                MmCached,
                                                NULL,
                                                0, 
                                                NormalPagePriority);
    }
    
    //
    // Make sure we were able to map it
    //
    CurrentBase = SystemVa;
    if (!SystemVa) return STATUS_INSUFFICIENT_RESOURCES;
    
    //
    // Initialize default
    //
    Irp->IoStatus.Information = 0;
    
    //
    // Get the I/O Stack Location and capture the data
    //
    IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
    CurrentOffset = IoStackLocation->Parameters.Read.ByteOffset;
    BytesLeft = IoStackLocation->Parameters.Read.Length;
    if (!BytesLeft) return STATUS_INVALID_PARAMETER;
    
    //
    // Do the copy loop
    //
    while (TRUE)
    {
        //
        // Map the pages
        //
        BaseAddress = RamdiskMapPages(DeviceExtension,
                                      CurrentOffset,
                                      BytesLeft,
                                      &BytesRead);
        if (!BaseAddress) return STATUS_INSUFFICIENT_RESOURCES;
        
        //
        // Update our lengths
        //
        Irp->IoStatus.Information += BytesRead;
        CopyLength = BytesRead;
        
        //
        // Check if this was a read or write
        //
        Status = STATUS_SUCCESS;
        if (IoStackLocation->MajorFunction == IRP_MJ_READ)
        {
            //
            // Set our copy parameters
            //
            Destination = CurrentBase;
            Source = BaseAddress;
            goto DoCopy;
        }
        else if (IoStackLocation->MajorFunction == IRP_MJ_WRITE)
        {
            //
            // Set our copy parameters
            //
            Destination = BaseAddress;
            Source = CurrentBase;
DoCopy:
            //
            // Copy the data
            //
            RtlCopyMemory(Destination, Source, CopyLength);
        }
        else
        {
            //
            // Prepare us for failure
            //
            BytesLeft = CopyLength;
            Status = STATUS_INVALID_PARAMETER;
        }
        
        //
        // Unmap the pages
        //
        RamdiskUnmapPages(DeviceExtension,
                          BaseAddress,
                          CurrentOffset,
                          BytesRead);
        
        //
        // Update offset and bytes left
        //
        BytesLeft -= BytesRead;
        CurrentOffset.QuadPart += BytesRead;
        CurrentBase = (PVOID)((ULONG_PTR)CurrentBase + BytesRead);
        
        //
        // Check if we're done
        //
        if (!BytesLeft) return Status;
    }
}

NTSTATUS
NTAPI
RamdiskGetPartitionInfo(IN PIRP Irp,
                        IN PRAMDISK_DRIVE_EXTENSION DeviceExtension)
{
    NTSTATUS Status;
    PPARTITION_INFORMATION PartitionInfo;
    PVOID BaseAddress;
    LARGE_INTEGER Zero = {{0, 0}};
    ULONG Length;
    PIO_STACK_LOCATION IoStackLocation;
    
    //
    // Validate the length
    //
    IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
    if (IoStackLocation->Parameters.DeviceIoControl.
        OutputBufferLength < sizeof(PARTITION_INFORMATION))
    {
        //
        // Invalid length
        //
        Status = STATUS_BUFFER_TOO_SMALL;
        Irp->IoStatus.Status = Status;
        Irp->IoStatus.Information = 0;
        return Status;
    }
    
    //
    // Map the partition table
    //
    BaseAddress = RamdiskMapPages(DeviceExtension, Zero, PAGE_SIZE, &Length);
    if (!BaseAddress)
    {
        //
        // No memory
        //
        Status = STATUS_INSUFFICIENT_RESOURCES;
        Irp->IoStatus.Status = Status;
        Irp->IoStatus.Information = 0;
        return Status;
    }
    
    //
    // Fill out the information
    //
    PartitionInfo = Irp->AssociatedIrp.SystemBuffer;
    PartitionInfo->StartingOffset.QuadPart = DeviceExtension->BytesPerSector;
    PartitionInfo->PartitionLength.QuadPart = DeviceExtension->BytesPerSector *
                                              DeviceExtension->SectorsPerTrack *
                                              DeviceExtension->NumberOfHeads *
                                              DeviceExtension->Cylinders;
    PartitionInfo->HiddenSectors = DeviceExtension->HiddenSectors;
    PartitionInfo->PartitionNumber = 0;
    PartitionInfo->PartitionType = PARTITION_FAT32; //*((PCHAR)BaseAddress + 450);
    PartitionInfo->BootIndicator = (DeviceExtension->DiskType ==
                                    RAMDISK_BOOT_DISK) ? TRUE: FALSE;
    PartitionInfo->RecognizedPartition = IsRecognizedPartition(PartitionInfo->
                                                               PartitionType);
    PartitionInfo->RewritePartition = FALSE;

    //
    // Unmap the partition table
    //
    RamdiskUnmapPages(DeviceExtension, BaseAddress, Zero, Length);
    
    //
    // Done
    //
    Irp->IoStatus.Status = STATUS_SUCCESS;
    Irp->IoStatus.Information = sizeof(PARTITION_INFORMATION);
    return STATUS_SUCCESS;
}

NTSTATUS
NTAPI
RamdiskOpenClose(IN PDEVICE_OBJECT DeviceObject,
                 IN PIRP Irp)
{
    //
    // Complete the IRP
    //
    Irp->IoStatus.Information = 1;
    Irp->IoStatus.Status = STATUS_SUCCESS;
    IoCompleteRequest(Irp, IO_NO_INCREMENT);
    return STATUS_SUCCESS;
}

NTSTATUS
NTAPI
RamdiskReadWrite(IN PDEVICE_OBJECT DeviceObject,
                 IN PIRP Irp)
{
    PRAMDISK_DRIVE_EXTENSION DeviceExtension;
    ULONG Length;
    LARGE_INTEGER ByteOffset;
    PIO_STACK_LOCATION IoStackLocation;
    NTSTATUS Status, ReturnStatus;
    
    //
    // Get the device extension and make sure this isn't a bus
    //
    DeviceExtension = DeviceObject->DeviceExtension;
    if (DeviceExtension->Type == RamdiskBus)
    {
        //
        // Fail
        //
        Status = STATUS_INVALID_DEVICE_REQUEST;
        goto Complete;
    }
    
    //
    // Capture parameters
    //
    IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
    Length = IoStackLocation->Parameters.Read.Length;
    ByteOffset = IoStackLocation->Parameters.Read.ByteOffset;
    
    //
    // FIXME: Validate offset
    //
    
    //
    // FIXME: Validate sector
    //
    
    //
    // Validate write
    //
    if ((IoStackLocation->MajorFunction == IRP_MJ_WRITE) &&
        (DeviceExtension->DiskOptions.Readonly))
    {
        //
        // Fail, this is read-only
        //
        Status = STATUS_MEDIA_WRITE_PROTECTED;
        goto Complete;
    }
    
    //
    // See if we want to do this sync or async
    //
    if (DeviceExtension->DiskType > RAMDISK_MEMORY_MAPPED_DISK)
    {
        //
        // Do it sync
        //
        Status = RamdiskReadWriteReal(Irp, DeviceExtension);
        goto Complete;
    }
    
    //
    // Queue it to the worker
    //
    Status = SendIrpToThread(DeviceObject, Irp);
    ReturnStatus = STATUS_PENDING;
    
    //
    // Check if we're pending or not
    //
    if (Status != STATUS_PENDING)
    {
Complete:
        //
        // Complete the IRP
        //
        Irp->IoStatus.Status = Status;
        IoCompleteRequest(Irp, IO_DISK_INCREMENT);
        ReturnStatus = Status;
    }
    
    //
    // Return to caller
    //
    return ReturnStatus;
}

NTSTATUS
NTAPI
RamdiskDeviceControl(IN PDEVICE_OBJECT DeviceObject,
                     IN PIRP Irp)
{
    NTSTATUS Status;
    PIO_STACK_LOCATION IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
    PRAMDISK_BUS_EXTENSION DeviceExtension = DeviceObject->DeviceExtension;
    PRAMDISK_DRIVE_EXTENSION DriveExtension = (PVOID)DeviceExtension;
    ULONG Information;
    PCDROM_TOC Toc;
    PDISK_GEOMETRY DiskGeometry;
    
    //
    // Grab the remove lock
    //
    Status = IoAcquireRemoveLock(&DeviceExtension->RemoveLock, Irp);
    if (!NT_SUCCESS(Status))
    {
        //
        // Fail the IRP
        //
        Irp->IoStatus.Information = 0;
        Irp->IoStatus.Status = Status;
        IoCompleteRequest(Irp, IO_NO_INCREMENT);
        return Status;
    }
    
    //
    // Setup some defaults
    //
    Status = STATUS_INVALID_DEVICE_REQUEST;
    Information = 0;
    
    //
    // Check if this is an bus device or the drive
    //
    if (DeviceExtension->Type == RamdiskBus)
    {
        //
        // Check what the request is
        //
        switch (IoStackLocation->Parameters.DeviceIoControl.IoControlCode)
        {
            //
            // Request to create a ramdisk
            //
            case FSCTL_CREATE_RAM_DISK:
                
                //
                // Do it
                //
                Status = RamdiskCreateRamdisk(DeviceObject, Irp, TRUE);
                if (!NT_SUCCESS(Status)) goto CompleteRequest;
                break;
                
            default:
                
                //
                // We don't handle anything else yet
                //
                ASSERT(FALSE);
                while (TRUE);
        }
    }
    else
    {
        //
        // Check what the request is
        //
        switch (IoStackLocation->Parameters.DeviceIoControl.IoControlCode)
        {
            case IOCTL_DISK_CHECK_VERIFY:
            case IOCTL_STORAGE_CHECK_VERIFY:
            case IOCTL_STORAGE_CHECK_VERIFY2:
            case IOCTL_CDROM_CHECK_VERIFY:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;

            case IOCTL_STORAGE_GET_MEDIA_TYPES:
            case IOCTL_DISK_GET_MEDIA_TYPES:
            case IOCTL_DISK_GET_DRIVE_GEOMETRY:
            case IOCTL_CDROM_GET_DRIVE_GEOMETRY:
                
                //
                // Validate the length
                //
                if (IoStackLocation->Parameters.DeviceIoControl.
                    OutputBufferLength < sizeof(DISK_GEOMETRY))
                {
                    //
                    // Invalid length
                    //
                    Status = STATUS_BUFFER_TOO_SMALL;
                    break;
                }
                
                //
                // Fill it out
                //
                DiskGeometry = Irp->AssociatedIrp.SystemBuffer;
                DiskGeometry->Cylinders.QuadPart = DriveExtension->Cylinders;
                DiskGeometry->BytesPerSector = DriveExtension->BytesPerSector;
                DiskGeometry->SectorsPerTrack = DriveExtension->SectorsPerTrack;
                DiskGeometry->TracksPerCylinder = DriveExtension->NumberOfHeads;
                DiskGeometry->MediaType = DriveExtension->DiskOptions.Fixed ?
                                          FixedMedia : RemovableMedia;
                
                //
                // We're done
                //
                Status = STATUS_SUCCESS;
                Information = sizeof(DISK_GEOMETRY);
                break;
            
            //
            // Hack to support ReactOS's broken CDFS
            //
            case IOCTL_CDROM_GET_LAST_SESSION:
            
                //
                // Validate the length
                //
                if (IoStackLocation->Parameters.DeviceIoControl.
                    OutputBufferLength < RAMDISK_SESSION_SIZE)
                {
                    //
                    // Invalid length
                    //
                    Status = STATUS_BUFFER_TOO_SMALL;
                    break;
                }
                
                //
                // Fill out the TOC
                //
                Toc = Irp->AssociatedIrp.SystemBuffer;
                Toc->Length[0] = 0;
                Toc->Length[1] = RAMDISK_SESSION_SIZE - sizeof(Toc->Length);
                Toc->FirstTrack = 1;
                Toc->LastTrack = 1;
                Toc->TrackData[0].Adr = 1;
                Toc->TrackData[0].Control = TOC_DATA_TRACK;
                Toc->TrackData[0].TrackNumber = 1;
                Toc->TrackData[0].Address[0] =
                Toc->TrackData[0].Address[1] =
                Toc->TrackData[0].Address[2] =
                Toc->TrackData[0].Address[3] = 0;
                                
                //
                // We're done
                //
                Status = STATUS_SUCCESS;
                Information = RAMDISK_SESSION_SIZE;
                break;
                                
            case IOCTL_CDROM_READ_TOC:
                
                //
                // Validate the length
                //
                if (IoStackLocation->Parameters.DeviceIoControl.
                    OutputBufferLength < sizeof(CDROM_TOC))
                {
                    //
                    // Invalid length
                    //
                    Status = STATUS_BUFFER_TOO_SMALL;
                    break;
                }
                
                //
                // Clear the TOC
                //
                Toc = Irp->AssociatedIrp.SystemBuffer;
                RtlZeroMemory(Toc, sizeof(CDROM_TOC));
                
                //
                // Fill it out
                //
                Toc->Length[0] = 0;
                Toc->Length[1] = RAMDISK_TOC_SIZE - sizeof(Toc->Length);
                Toc->FirstTrack = 1;
                Toc->LastTrack = 1;
                Toc->TrackData[0].Adr = 1;
                Toc->TrackData[0].Control = TOC_DATA_TRACK;
                Toc->TrackData[0].TrackNumber = 1;
                
                //
                // We're done
                //
                Status = STATUS_SUCCESS;
                Information = RAMDISK_TOC_SIZE;
                break;
                
            case IOCTL_DISK_SET_PARTITION_INFO:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            case IOCTL_DISK_GET_PARTITION_INFO:
                
                //
                // Validate the length
                //
                if (IoStackLocation->Parameters.DeviceIoControl.
                    OutputBufferLength < sizeof(PARTITION_INFORMATION))
                {
                    //
                    // Invalid length
                    //
                    Status = STATUS_BUFFER_TOO_SMALL;
                    break;
                }
                
                //
                // Check if we need to do this sync or async
                //
                if (DriveExtension->DiskType > RAMDISK_MEMORY_MAPPED_DISK)
                {
                    //
                    // Call the helper function
                    //
                    Status = RamdiskGetPartitionInfo(Irp, DriveExtension);
                }
                else
                {
                    //
                    // Do it asynchronously later
                    //
                    goto CallWorker;
                }
                
                //
                // We're done
                //
                Information = Irp->IoStatus.Information;
                break;
                
            case IOCTL_DISK_GET_DRIVE_LAYOUT:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            case IOCTL_DISK_GET_LENGTH_INFO:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            case IOCTL_DISK_IS_WRITABLE:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            case IOCTL_SCSI_MINIPORT:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            case IOCTL_STORAGE_QUERY_PROPERTY:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            case IOCTL_MOUNTDEV_QUERY_UNIQUE_ID:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            case IOCTL_MOUNTDEV_QUERY_STABLE_GUID:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            case IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            case IOCTL_VOLUME_SET_GPT_ATTRIBUTES:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            case IOCTL_VOLUME_GET_GPT_ATTRIBUTES:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            case IOCTL_VOLUME_OFFLINE:
                
                UNIMPLEMENTED;
                while (TRUE);
                break;
                
            default:
         
                //
                // Drive code not emulated
                //
                DPRINT1("IOCTL: %lx\n", IoStackLocation->Parameters.DeviceIoControl.IoControlCode);                
                break;
        }

        //
        // If requests drop down here, we just return them complete them
        //
        goto CompleteRequest;
    }
    
    //
    // Queue the request to our worker thread
    //
CallWorker:
    Status = SendIrpToThread(DeviceObject, Irp);
    
CompleteRequest:
    //
    // Release the lock
    //
    IoReleaseRemoveLock(&DeviceExtension->RemoveLock, Irp);
    if (Status != STATUS_PENDING)
    {
        //
        // Complete the request
        //
        Irp->IoStatus.Status = Status;
        Irp->IoStatus.Information = Information;
        IoCompleteRequest(Irp, IO_NO_INCREMENT);
    }
    
    //
    // Return status
    //
    return Status;
}

NTSTATUS
NTAPI
RamdiskQueryDeviceRelations(IN DEVICE_RELATION_TYPE Type,
                            IN PDEVICE_OBJECT DeviceObject,
                            IN PIRP Irp)
{
    PRAMDISK_BUS_EXTENSION DeviceExtension;
    PRAMDISK_DRIVE_EXTENSION DriveExtension;
    PDEVICE_RELATIONS DeviceRelations, OurDeviceRelations;
    ULONG Count, DiskCount, FinalCount;
    PLIST_ENTRY ListHead, NextEntry;
    PDEVICE_OBJECT* DriveDeviceObject;
    RAMDISK_DEVICE_STATE State;
    
    //
    // Get the device extension and check if this is a drive
    //
    DeviceExtension = DeviceObject->DeviceExtension;
    if (DeviceExtension->Type == RamdiskDrive)
    {
        //
        // FIXME: TODO
        //
        UNIMPLEMENTED;
        while (TRUE);
    }
    
    //
    // Anything but bus relations, we don't handle
    //
    if (Type) goto PassToNext;
    
    //
    // Acquire the disk list lock
    //
    KeEnterCriticalRegion();
    ExAcquireFastMutex(&DeviceExtension->DiskListLock);
    
    //
    // Did a device already fill relations?
    //
    DeviceRelations = (PDEVICE_RELATIONS)Irp->IoStatus.Information;
    if (DeviceRelations)
    {
        //
        // Use the data
        //
        Count = DeviceRelations->Count;
    }
    else
    {
        //
        // We're the first
        //
        Count = 0;
    }
    
    //
    // Now loop our drives
    //
    DiskCount = 0;
    ListHead = &DeviceExtension->DiskList;
    NextEntry = ListHead->Flink;
    while (NextEntry != ListHead)
    {
        //
        // As long as it wasn't removed, count it in
        //
        DriveExtension = CONTAINING_RECORD(NextEntry,
                                           RAMDISK_DRIVE_EXTENSION,
                                           DiskList);
        if (DriveExtension->State < RamdiskStateBusRemoved) DiskCount++;
        
        //
        // Move to the next one
        //
        NextEntry = NextEntry->Flink;
    }
    
    //
    // Now we know our final count
    //
    FinalCount = Count + DiskCount;
    
    //
    // Allocate the structure
    //
    OurDeviceRelations = ExAllocatePoolWithTag(PagedPool,
                                               FIELD_OFFSET(DEVICE_RELATIONS,
                                                            Objects) +
                                               FinalCount *
                                               sizeof(PDEVICE_OBJECT),
                                               'dmaR');
    if (!OurDeviceRelations)
    {
        //
        // Fail
        //
        ExReleaseFastMutex(&DeviceExtension->DiskListLock);
        KeLeaveCriticalRegion();
        Irp->IoStatus.Status = STATUS_INSUFFICIENT_RESOURCES;
        IoCompleteRequest(Irp, IO_NO_INCREMENT);
        return STATUS_INSUFFICIENT_RESOURCES;
    }
    
    //
    // Check if we already had some relations
    //
    if (Count)
    {
        //
        // Copy them in
        //
        RtlCopyMemory(OurDeviceRelations->Objects,
                      DeviceRelations->Objects,
                      Count * sizeof(PDEVICE_OBJECT));
    }
    
    //
    // Save the count
    //
    OurDeviceRelations->Count = FinalCount;
    
    //
    // Now loop our drives again
    //
    ListHead = &DeviceExtension->DiskList;
    NextEntry = ListHead->Flink;
    while (NextEntry != ListHead)
    {
        //
        // Go to the end of the list
        //
        DriveDeviceObject = &OurDeviceRelations->Objects[Count];
        
        //
        // Get the drive state
        //
        DriveExtension = CONTAINING_RECORD(NextEntry,
                                           RAMDISK_DRIVE_EXTENSION,
                                           DiskList);
        State = DriveExtension->State;
        
        //
        // If it was removed or enumerated, we don't touch the device object
        //
        if (State >= RamdiskStateBusRemoved)
        {
            //
            // If it was removed, we still have to keep track of this though
            //
            if (State == RamdiskStateBusRemoved)
            {
                //
                // Mark it as enumerated now, but don't actually reference it
                //
                DriveExtension->State = RamdiskStateEnumerated;
            }
        }
        else
        {
            //
            // First time it's enumerated, reference the device object
            //
            ObReferenceObject(DriveExtension->DeviceObject);
            
            //
            // Save the object pointer, and move on
            //
            *DriveDeviceObject++ = DriveExtension->DeviceObject;
        }
        
        if (DriveExtension->State < RamdiskStateBusRemoved) DiskCount++;
        
        //
        // Move to the next one
        //
        NextEntry = NextEntry->Flink;
    }

    //
    // Release the lock
    //
    ExReleaseFastMutex(&DeviceExtension->DiskListLock);
    KeLeaveCriticalRegion();
    
    //
    // Cleanup old relations
    //
    if (DeviceRelations) ExFreePool(DeviceRelations);
    
    //
    // Complete our IRP
    //
    Irp->IoStatus.Information = (ULONG_PTR)OurDeviceRelations;
    Irp->IoStatus.Status = STATUS_SUCCESS;
    
    //
    // Pass to the next driver
    //
PassToNext:
    IoCopyCurrentIrpStackLocationToNext(Irp);
    return IoCallDriver(DeviceExtension->AttachedDevice, Irp);  
}

NTSTATUS
NTAPI
RamdiskPnp(IN PDEVICE_OBJECT DeviceObject,
           IN PIRP Irp)
{
    PIO_STACK_LOCATION IoStackLocation;
    PRAMDISK_BUS_EXTENSION DeviceExtension;
    NTSTATUS Status;
    UCHAR Minor;
    
    //
    // Get the device extension and stack location
    //
    DeviceExtension = DeviceObject->DeviceExtension;
    IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
    Minor = IoStackLocation->MinorFunction;
    
    //
    // Check if the bus is removed
    //
    if (DeviceExtension->State == RamdiskStateBusRemoved)
    {
        //
        // Only remove-device and query-id are allowed
        //
        if ((Minor != IRP_MN_REMOVE_DEVICE) || (Minor != IRP_MN_QUERY_ID))
        {
            //
            // Fail anything else
            //
            Status = STATUS_NO_SUCH_DEVICE;
            Irp->IoStatus.Status = Status;
            IoCompleteRequest(Irp, IO_NO_INCREMENT);
            return Status;
        }
    }
    
    //
    // Acquire the remove lock
    //
    Status = IoAcquireRemoveLock(&DeviceExtension->RemoveLock, Irp);
    if (!NT_SUCCESS(Status))
    {
        //
        // Fail the IRP
        //
        Irp->IoStatus.Information = 0;
        Irp->IoStatus.Status = Status;
        IoCompleteRequest(Irp, IO_NO_INCREMENT);
        return Status;
    }
    
    //
    // Query the IRP type
    //
    switch (Minor)
    {
        case IRP_MN_START_DEVICE:
            
            DPRINT1("PnP IRP: %lx\n", Minor);
            while (TRUE);
            break;
            
        case IRP_MN_QUERY_STOP_DEVICE:
            
            DPRINT1("PnP IRP: %lx\n", Minor);
            while (TRUE);
            break;
            
        case IRP_MN_CANCEL_STOP_DEVICE:
            
            DPRINT1("PnP IRP: %lx\n", Minor);
            while (TRUE);
            break;
            
        case IRP_MN_STOP_DEVICE:
            
            DPRINT1("PnP IRP: %lx\n", Minor);
            while (TRUE);
            break;
            
        case IRP_MN_QUERY_REMOVE_DEVICE:
            
            DPRINT1("PnP IRP: %lx\n", Minor);
            while (TRUE);
            break;
            
        case IRP_MN_CANCEL_REMOVE_DEVICE:
            
            DPRINT1("PnP IRP: %lx\n", Minor);
            while (TRUE);
            break;
            
        case IRP_MN_REMOVE_DEVICE:
            
            DPRINT1("PnP IRP: %lx\n", Minor);
            while (TRUE);
            break;

        case IRP_MN_SURPRISE_REMOVAL:
            
            DPRINT1("PnP IRP: %lx\n", Minor);
            while (TRUE);
            break;
            
        case IRP_MN_QUERY_ID:
            
            //
            // Are we a drive?
            //
            if (DeviceExtension->Type == RamdiskDrive)
            {
                DPRINT1("PnP IRP: %lx\n", Minor);
                while (TRUE);
            }
            break;
            
        case IRP_MN_QUERY_BUS_INFORMATION:
            
            //
            // Are we a drive?
            //
            if (DeviceExtension->Type == RamdiskDrive)
            {
                DPRINT1("PnP IRP: %lx\n", Minor);
                while (TRUE);
            }
            break;
            
        case IRP_MN_EJECT:
            
            DPRINT1("PnP IRP: %lx\n", Minor);
            while (TRUE);
            break;
            
        case IRP_MN_QUERY_DEVICE_TEXT:
            
            //
            // Are we a drive?
            //
            if (DeviceExtension->Type == RamdiskDrive)
            {
                DPRINT1("PnP IRP: %lx\n", Minor);
                while (TRUE);
            }
            break;
            
        case IRP_MN_QUERY_DEVICE_RELATIONS:

            //
            // Call our main routine
            //
            Status = RamdiskQueryDeviceRelations(IoStackLocation->
                                                 Parameters.
                                                 QueryDeviceRelations.Type,
                                                 DeviceObject,
                                                 Irp);
            goto ReleaseAndReturn;
            
        case IRP_MN_QUERY_CAPABILITIES:
            
            //
            // Are we a drive?
            //
            if (DeviceExtension->Type == RamdiskDrive)
            {
                DPRINT1("PnP IRP: %lx\n", Minor);
                while (TRUE);
            }
            break;
            
        case IRP_MN_QUERY_RESOURCES:
        case IRP_MN_QUERY_RESOURCE_REQUIREMENTS:
            
            //
            // Complete immediately without touching it
            //
            IoCompleteRequest(Irp, IO_NO_INCREMENT);
            goto ReleaseAndReturn;
            
        default:
            
            DPRINT1("Illegal IRP: %lx\n", Minor);
            break;
    }
    
    //
    // Are we the bus?
    //
    if (DeviceExtension->Type == RamdiskBus)
    {
        //
        // Do we have an attached device?
        //
        if (DeviceExtension->AttachedDevice)
        {
            //
            // Forward the IRP
            //
            IoSkipCurrentIrpStackLocation(Irp);
            Status = IoCallDriver(DeviceExtension->AttachedDevice, Irp);
        }
    }
    
    //
    // Release the lock and return status
    //
ReleaseAndReturn:
    IoReleaseRemoveLock(&DeviceExtension->RemoveLock, Irp);
    return Status;
}

NTSTATUS
NTAPI
RamdiskPower(IN PDEVICE_OBJECT DeviceObject,
             IN PIRP Irp)
{
    UNIMPLEMENTED;
    while (TRUE);
    return STATUS_SUCCESS;
}

NTSTATUS
NTAPI
RamdiskSystemControl(IN PDEVICE_OBJECT DeviceObject,
                     IN PIRP Irp)
{
    UNIMPLEMENTED;
    while (TRUE);
    return STATUS_SUCCESS;
}

NTSTATUS
NTAPI
RamdiskScsi(IN PDEVICE_OBJECT DeviceObject,
            IN PIRP Irp)
{
    UNIMPLEMENTED;
    while (TRUE);
    return STATUS_SUCCESS;
}

NTSTATUS
NTAPI
RamdiskFlushBuffers(IN PDEVICE_OBJECT DeviceObject,
                    IN PIRP Irp)
{
    UNIMPLEMENTED;
    while (TRUE);
    return STATUS_SUCCESS;
}

VOID
NTAPI
RamdiskUnload(IN PDRIVER_OBJECT DriverObject)
{
    UNIMPLEMENTED;
    while (TRUE);
}

NTSTATUS
NTAPI
RamdiskAddDevice(IN PDRIVER_OBJECT DriverObject, 
                 IN PDEVICE_OBJECT PhysicalDeviceObject)
{
	PRAMDISK_BUS_EXTENSION DeviceExtension;
	PDEVICE_OBJECT AttachedDevice;
	NTSTATUS Status; 
	UNICODE_STRING DeviceName;
	PDEVICE_OBJECT DeviceObject;
	
	//
	// Only create the bus FDO once
	//
	if (RamdiskBusFdo) return STATUS_DEVICE_ALREADY_ATTACHED;
	
	//
	// Create the bus FDO
	//
	RtlInitUnicodeString(&DeviceName, L"\\Device\\Ramdisk");
	Status = IoCreateDevice(DriverObject,
						    sizeof(RAMDISK_BUS_EXTENSION),
							&DeviceName,
							FILE_DEVICE_BUS_EXTENDER,
							FILE_DEVICE_SECURE_OPEN,
							0,
							&DeviceObject);
	if (NT_SUCCESS(Status))
	{
		//
		// Initialize the bus FDO extension
		//
	    DeviceExtension = DeviceObject->DeviceExtension;
	    RtlZeroMemory(DeviceObject->DeviceExtension,
                      sizeof(RAMDISK_BUS_EXTENSION));

		//
		// Set bus FDO flags
		//
	    DeviceObject->Flags |= DO_POWER_PAGABLE | DO_DIRECT_IO;

		//
		// Setup the bus FDO extension
		//
	    DeviceExtension->Type = RamdiskBus;
		ExInitializeFastMutex(&DeviceExtension->DiskListLock);
	    IoInitializeRemoveLock(&DeviceExtension->RemoveLock,
                               'dmaR',
                               0,
                               1);
		InitializeListHead(&DeviceExtension->DiskList);
	    DeviceExtension->PhysicalDeviceObject = PhysicalDeviceObject;
	    DeviceExtension->DeviceObject = DeviceObject;

		//
		// Register the RAM disk device interface
		//
	    Status = IoRegisterDeviceInterface(PhysicalDeviceObject,
										   &RamdiskBusInterface,
										   NULL,
										   &DeviceExtension->BusDeviceName);
	    if (!NT_SUCCESS(Status))
	    {
			//
			// Fail
			//
			IoDeleteDevice(DeviceObject);
			return Status;
	    }

		//
		// Attach us to the device stack
		//
	    AttachedDevice = IoAttachDeviceToDeviceStack(DeviceObject,
													 PhysicalDeviceObject);
	    DeviceExtension->AttachedDevice = AttachedDevice;
	    if (!AttachedDevice)
	    {
			//
			// Fail
			//
			IoSetDeviceInterfaceState(&DeviceExtension->BusDeviceName, 0);
			RtlFreeUnicodeString(&DeviceExtension->BusDeviceName);
			IoDeleteDevice(DeviceObject);
			return STATUS_NO_SUCH_DEVICE;
	    }

		//
		// Bus FDO is initialized
		//
	    RamdiskBusFdo = DeviceObject;

		//
		// Loop for loader block
		//
	    if (KeLoaderBlock)
	    {
			//
			// Are we being booted from setup? Not yet supported
			//
			//ASSERT(!KeLoaderBlock->SetupLdrBlock);
	    }

		//
		// All done
		//
	    DeviceObject->Flags &= DO_DEVICE_INITIALIZING;
	    Status = STATUS_SUCCESS;
	}

	//
	// Return status
	//
	return Status;
}

NTSTATUS
NTAPI
DriverEntry(IN PDRIVER_OBJECT DriverObject,
            IN PUNICODE_STRING RegistryPath)
{
    PCHAR BootDeviceName, CommandLine;
    PDEVICE_OBJECT PhysicalDeviceObject = NULL;
    NTSTATUS Status;
    DPRINT("RAM Disk Driver Initialized\n");
    
    //
    // Query ramdisk parameters
    //
    QueryParameters(RegistryPath);
    
    //
    // Save the registry path
    //
    DriverRegistryPath = *RegistryPath;
    DriverRegistryPath.Buffer = ExAllocatePoolWithTag(PagedPool,
                                                      RegistryPath->Length +
                                                      sizeof(WCHAR),
                                                      'dmaR');
    if (!DriverRegistryPath.Buffer) return STATUS_INSUFFICIENT_RESOURCES;
    RtlCopyUnicodeString(&DriverRegistryPath, RegistryPath);
    
    //
    // Set device routines
    //
    DriverObject->MajorFunction[IRP_MJ_CREATE] = RamdiskOpenClose;
    DriverObject->MajorFunction[IRP_MJ_CLOSE] = RamdiskOpenClose;
    DriverObject->MajorFunction[IRP_MJ_READ] = RamdiskReadWrite;
    DriverObject->MajorFunction[IRP_MJ_WRITE] = RamdiskReadWrite;
    DriverObject->MajorFunction[IRP_MJ_DEVICE_CONTROL] = RamdiskDeviceControl;
    DriverObject->MajorFunction[IRP_MJ_PNP] = RamdiskPnp;
    DriverObject->MajorFunction[IRP_MJ_POWER] = RamdiskPower;
    DriverObject->MajorFunction[IRP_MJ_SYSTEM_CONTROL] = RamdiskSystemControl;
    DriverObject->MajorFunction[IRP_MJ_SCSI] = RamdiskScsi;
    DriverObject->MajorFunction[IRP_MJ_FLUSH_BUFFERS] = RamdiskFlushBuffers;
    DriverObject->DriverExtension->AddDevice = RamdiskAddDevice;
    DriverObject->DriverUnload = RamdiskUnload;
    
    //
    // Check for a loader block
    //
    if (KeLoaderBlock)
    {
        //
        // Get the boot device name
        //
        BootDeviceName = KeLoaderBlock->ArcBootDeviceName;
        if (BootDeviceName)
        {
            //
            // Check if we're booting from ramdisk
            //
            if ((strlen(BootDeviceName) >= 10) &&
                !(_strnicmp(BootDeviceName, "ramdisk(0)", 10)))
            {
                //
                // We'll have to tell the PnP Manager
                //
                ReportDetectedDevice = TRUE;
                
                //
                // Check for a command line
                //
                CommandLine = KeLoaderBlock->LoadOptions;
                if (CommandLine)
                {
                    //
                    // Check if this is an ISO boot
                    //
                    if (strstr(CommandLine, "RDEXPORTASCD"))
                    {
                        //
                        // Remember for later
                        //
                        ExportBootDiskAsCd = TRUE;
                    }
                    
                    //
                    // Check if this is PE boot
                    //
                    if (strstr(CommandLine, "MININT"))
                    {
                        //
                        // Remember for later
                        //
                        IsWinPEBoot = TRUE;
                    }
                }
            }
            
        }
    }
    
    //
    // Installing from Ramdisk isn't supported yet
    //
    //ASSERT(!KeLoaderBlock->SetupLdrBlock);
    
    //
    // Are we reporting the device
    //
    if (ReportDetectedDevice)
    {
        //
        // Do it
        //
        Status = IoReportDetectedDevice(DriverObject,
                                        InterfaceTypeUndefined,
                                        0xFFFFFFFF,
                                        0xFFFFFFFF,
                                        NULL,
                                        NULL,
                                        0,
                                        &PhysicalDeviceObject);
        if (NT_SUCCESS(Status))
        {
            //
            // ReactOS Fix
            // The ReactOS Plug and Play Manager is broken and does not create
            // the required keys when reporting a detected device.
            // We hack around this ourselves.
            //
            RtlCreateUnicodeString(&((PEXTENDED_DEVOBJ_EXTENSION)
                                   PhysicalDeviceObject->DeviceObjectExtension)
                                   ->DeviceNode->InstancePath,
                                   L"Root\\UNKNOWN\\0000");
            
            //
            // Create the device object
            //
            Status = RamdiskAddDevice(DriverObject, PhysicalDeviceObject);
            if (NT_SUCCESS(Status))
            {
                //
                // We're done
                //
                PhysicalDeviceObject->Flags &= ~DO_DEVICE_INITIALIZING;
                Status = STATUS_SUCCESS;
            }
        }
    }
    else
    {
        //
        // Done
        //
        Status = STATUS_SUCCESS;
    }

    //
    // Done
    //
    return Status;
}