hwdisk.c File Reference

#include <freeldr.h>
#include <debug.h>

Include dependency graph for hwdisk.c:

Go to the source code of this file.

Classes
struct	tagDISKCONTEXT

Typedefs
typedef struct tagDISKCONTEXT	DISKCONTEXT

Functions
	DBG_DEFAULT_CHANNEL (HWDETECT)
static ARC_STATUS	DiskClose (ULONG FileId)
static ARC_STATUS	DiskGetFileInformation (ULONG FileId, FILEINFORMATION *Information)
static ARC_STATUS	DiskOpen (CHAR *Path, OPENMODE OpenMode, ULONG *FileId)
static ARC_STATUS	DiskRead (ULONG FileId, VOID *Buffer, ULONG N, ULONG *Count)
static ARC_STATUS	DiskSeek (ULONG FileId, LARGE_INTEGER *Position, SEEKMODE SeekMode)
PCHAR	GetHarddiskIdentifier (UCHAR DriveNumber)
static VOID	GetHarddiskInformation (UCHAR DriveNumber)
static UCHAR	EnumerateHarddisks (OUT PBOOLEAN BootDriveReported)
static BOOLEAN	DiskIsDriveRemovable (UCHAR DriveNumber)
static BOOLEAN	DiskGetBootPath (BOOLEAN IsPxe)
BOOLEAN	PcInitializeBootDevices (VOID)

Variables
static const CHAR	Hex [] = "0123456789abcdef"
UCHAR	PcBiosDiskCount = 0
static CHAR	PcDiskIdentifier [32][20]
PVOID	DiskReadBuffer
SIZE_T	DiskReadBufferSize
static const DEVVTBL	DiskVtbl

Typedef Documentation

DISKCONTEXT

typedef struct tagDISKCONTEXT DISKCONTEXT

Function Documentation

DBG_DEFAULT_CHANNEL()

DBG_DEFAULT_CHANNEL

(

HWDETECT

)

DiskClose()

static ARC_STATUS DiskClose ( ULONG  FileId )

static

Definition at line 53 of file hwdisk.c.

{
    DISKCONTEXT* Context = FsGetDeviceSpecific(FileId);
    FrLdrTempFree(Context, TAG_HW_DISK_CONTEXT);
    return ESUCCESS;
}

DiskGetBootPath()

static BOOLEAN DiskGetBootPath ( BOOLEAN  IsPxe )

static

Definition at line 417 of file hwdisk.c.

{
    if (*FrLdrBootPath)
        return TRUE;
 
    // FIXME! FIXME! Do this in some drive recognition procedure!!!!
    if (IsPxe)
    {
        RtlStringCbCopyA(FrLdrBootPath, sizeof(FrLdrBootPath), "net(0)");
    }
    else
    /* 0x49 is our magic ramdisk drive, so try to detect it first */
    if (FrldrBootDrive == 0x49)
    {
        /* This is the ramdisk. See ArmInitializeBootDevices() too... */
        // RtlStringCbPrintfA(FrLdrBootPath, sizeof(FrLdrBootPath), "ramdisk(%u)", 0);
        RtlStringCbCopyA(FrLdrBootPath, sizeof(FrLdrBootPath), "ramdisk(0)");
    }
    else if (FrldrBootDrive < 0x80)
    {
        /* This is a floppy */
        RtlStringCbPrintfA(FrLdrBootPath, sizeof(FrLdrBootPath),
                           "multi(0)disk(0)fdisk(%u)", FrldrBootDrive);
    }
    else if (FrldrBootPartition == 0xFF)
    {
        /* Boot Partition 0xFF is the magic value that indicates booting from CD-ROM (see isoboot.S) */
        RtlStringCbPrintfA(FrLdrBootPath, sizeof(FrLdrBootPath),
                           "multi(0)disk(0)cdrom(%u)", FrldrBootDrive - 0x80);
    }
    else
    {
        ULONG BootPartition;
        PARTITION_TABLE_ENTRY PartitionEntry;
 
        /* This is a hard disk */
        if (!DiskGetBootPartitionEntry(FrldrBootDrive, &PartitionEntry, &BootPartition))
        {
            ERR("Failed to get boot partition entry\n");
            return FALSE;
        }
 
        FrldrBootPartition = BootPartition;
 
        RtlStringCbPrintfA(FrLdrBootPath, sizeof(FrLdrBootPath),
                           "multi(0)disk(0)rdisk(%u)partition(%lu)",
                           FrldrBootDrive - 0x80, FrldrBootPartition);
    }
 
    return TRUE;
}

Referenced by PcInitializeBootDevices().

DiskGetFileInformation()

static ARC_STATUS DiskGetFileInformation ( ULONG  FileId, FILEINFORMATION *  Information  )

static

Definition at line 61 of file hwdisk.c.

{
    DISKCONTEXT* Context = FsGetDeviceSpecific(FileId);
 
    RtlZeroMemory(Information, sizeof(*Information));
 
    /*
     * The ARC specification mentions that for partitions, StartingAddress and
     * EndingAddress are the start and end positions of the partition in terms
     * of byte offsets from the start of the disk.
     * CurrentAddress is the current offset into (i.e. relative to) the partition.
     */
    Information->StartingAddress.QuadPart = Context->SectorOffset * Context->SectorSize;
    Information->EndingAddress.QuadPart   = (Context->SectorOffset + Context->SectorCount) * Context->SectorSize;
    Information->CurrentAddress.QuadPart  = Context->SectorNumber * Context->SectorSize;
 
    return ESUCCESS;
}

DiskIsDriveRemovable()

static BOOLEAN DiskIsDriveRemovable ( UCHAR  DriveNumber )

static

Definition at line 402 of file hwdisk.c.

{
    /*
     * Hard disks use drive numbers >= 0x80 . So if the drive number
     * indicates a hard disk then return FALSE.
     * 0x49 is our magic ramdisk drive, so return FALSE for that too.
     */
    if ((DriveNumber >= 0x80) || (DriveNumber == 0x49))
        return FALSE;
 
    /* The drive is a floppy diskette so return TRUE */
    return TRUE;
}

Referenced by PcInitializeBootDevices().

DiskOpen()

static ARC_STATUS DiskOpen ( CHAR *  Path, OPENMODE  OpenMode, ULONG *  FileId  )

static

Definition at line 81 of file hwdisk.c.

{
    DISKCONTEXT* Context;
    UCHAR DriveNumber;
    ULONG DrivePartition, SectorSize;
    ULONGLONG SectorOffset = 0;
    ULONGLONG SectorCount = 0;
    PARTITION_TABLE_ENTRY PartitionTableEntry;
 
    if (DiskReadBufferSize == 0)
    {
        ERR("DiskOpen(): DiskReadBufferSize is 0, something is wrong.\n");
        ASSERT(FALSE);
        return ENOMEM;
    }
 
    if (!DissectArcPath(Path, NULL, &DriveNumber, &DrivePartition))
        return EINVAL;
 
    if (DrivePartition == 0xff)
    {
        /* This is a CD-ROM device */
        SectorSize = 2048;
    }
    else
    {
        /*
         * This is either a floppy disk device (DrivePartition == 0) or
         * a hard disk device (DrivePartition != 0 && DrivePartition != 0xFF)
         * but it doesn't matter which one because they both have 512 bytes
         * per sector.
         */
        SectorSize = 512;
    }
 
    if (DrivePartition != 0xff && DrivePartition != 0)
    {
        if (!DiskGetPartitionEntry(DriveNumber, DrivePartition, &PartitionTableEntry))
            return EINVAL;
 
        SectorOffset = PartitionTableEntry.SectorCountBeforePartition;
        SectorCount = PartitionTableEntry.PartitionSectorCount;
    }
    else
    {
        GEOMETRY Geometry;
        if (!MachDiskGetDriveGeometry(DriveNumber, &Geometry))
            return EINVAL;
 
        if (SectorSize != Geometry.BytesPerSector)
        {
            ERR("SectorSize (%lu) != Geometry.BytesPerSector (%lu), expect problems!\n",
                SectorSize, Geometry.BytesPerSector);
        }
 
        SectorOffset = 0;
        SectorCount = (ULONGLONG)Geometry.Cylinders * Geometry.Heads * Geometry.Sectors;
    }
 
    Context = FrLdrTempAlloc(sizeof(DISKCONTEXT), TAG_HW_DISK_CONTEXT);
    if (!Context)
        return ENOMEM;
 
    Context->DriveNumber = DriveNumber;
    Context->SectorSize = SectorSize;
    Context->SectorOffset = SectorOffset;
    Context->SectorCount = SectorCount;
    Context->SectorNumber = 0;
    FsSetDeviceSpecific(*FileId, Context);
 
    return ESUCCESS;
}

DiskRead()

static ARC_STATUS DiskRead ( ULONG  FileId, VOID *  Buffer, ULONG  N, ULONG *  Count  )

static

Definition at line 155 of file hwdisk.c.

{
    DISKCONTEXT* Context = FsGetDeviceSpecific(FileId);
    UCHAR* Ptr = (UCHAR*)Buffer;
    ULONG Length, TotalSectors, MaxSectors, ReadSectors;
    ULONGLONG SectorOffset;
    BOOLEAN ret;
 
    ASSERT(DiskReadBufferSize > 0);
 
    TotalSectors = (N + Context->SectorSize - 1) / Context->SectorSize;
    MaxSectors   = DiskReadBufferSize / Context->SectorSize;
    SectorOffset = Context->SectorOffset + Context->SectorNumber;
 
    // If MaxSectors is 0, this will lead to infinite loop.
    // In release builds assertions are disabled, however we also have sanity checks in DiskOpen()
    ASSERT(MaxSectors > 0);
 
    ret = TRUE;
 
    while (TotalSectors)
    {
        ReadSectors = TotalSectors;
        if (ReadSectors > MaxSectors)
            ReadSectors = MaxSectors;
 
        ret = MachDiskReadLogicalSectors(Context->DriveNumber,
                                         SectorOffset,
                                         ReadSectors,
                                         DiskReadBuffer);
        if (!ret)
            break;
 
        Length = ReadSectors * Context->SectorSize;
        if (Length > N)
            Length = N;
 
        RtlCopyMemory(Ptr, DiskReadBuffer, Length);
 
        Ptr += Length;
        N -= Length;
        SectorOffset += ReadSectors;
        TotalSectors -= ReadSectors;
    }
 
    *Count = (ULONG)((ULONG_PTR)Ptr - (ULONG_PTR)Buffer);
    Context->SectorNumber = SectorOffset - Context->SectorOffset;
 
    return (!ret) ? EIO : ESUCCESS;
}

DiskSeek()

static ARC_STATUS DiskSeek ( ULONG  FileId, LARGE_INTEGER *  Position, SEEKMODE  SeekMode  )

static

Definition at line 207 of file hwdisk.c.

{
    DISKCONTEXT* Context = FsGetDeviceSpecific(FileId);
    LARGE_INTEGER NewPosition = *Position;
 
    switch (SeekMode)
    {
        case SeekAbsolute:
            break;
        case SeekRelative:
            NewPosition.QuadPart += (Context->SectorNumber * Context->SectorSize);
            break;
        default:
            ASSERT(FALSE);
            return EINVAL;
    }
 
    if (NewPosition.QuadPart & (Context->SectorSize - 1))
        return EINVAL;
 
    /* Convert in number of sectors */
    NewPosition.QuadPart /= Context->SectorSize;
 
    /* HACK: CDROMs may have a SectorCount of 0 */
    if (Context->SectorCount != 0 && NewPosition.QuadPart >= Context->SectorCount)
        return EINVAL;
 
    Context->SectorNumber = NewPosition.QuadPart;
    return ESUCCESS;
}

EnumerateHarddisks()

static UCHAR EnumerateHarddisks ( OUT PBOOLEAN  BootDriveReported )

static

Definition at line 342 of file hwdisk.c.

{
    UCHAR DiskCount, DriveNumber;
    ULONG i;
    BOOLEAN Changed;
 
    *BootDriveReported = FALSE;
 
    /* Count the number of visible harddisk drives */
    DiskReportError(FALSE);
    DiskCount = 0;
    DriveNumber = 0x80;
 
    ASSERT(DiskReadBufferSize > 0);
 
    /*
     * There are some really broken BIOSes out there. There are even BIOSes
     * that happily report success when you ask them to read from non-existent
     * harddisks. So, we set the buffer to known contents first, then try to
     * read. If the BIOS reports success but the buffer contents haven't
     * changed then we fail anyway.
     */
    memset(DiskReadBuffer, 0xcd, DiskReadBufferSize);
    while (MachDiskReadLogicalSectors(DriveNumber, 0ULL, 1, DiskReadBuffer))
    {
        Changed = FALSE;
        for (i = 0; !Changed && i < DiskReadBufferSize; i++)
        {
            Changed = ((PUCHAR)DiskReadBuffer)[i] != 0xcd;
        }
        if (!Changed)
        {
            TRACE("BIOS reports success for disk %d (0x%02X) but data didn't change\n",
                  (int)DiskCount, DriveNumber);
            break;
        }
 
        /* Cache the BIOS hard disk information for later use */
        GetHarddiskInformation(DriveNumber);
 
        /* Check if we have seen the boot drive */
        if (FrldrBootDrive == DriveNumber)
            *BootDriveReported = TRUE;
 
        DiskCount++;
        DriveNumber++;
        memset(DiskReadBuffer, 0xcd, DiskReadBufferSize);
    }
    DiskReportError(TRUE);
 
    PcBiosDiskCount = DiskCount;
    TRACE("BIOS reports %d harddisk%s\n",
          (int)DiskCount, (DiskCount == 1) ? "" : "s");
 
    return DiskCount;
}

Referenced by PcInitializeBootDevices().

GetHarddiskIdentifier()

PCHAR GetHarddiskIdentifier

(

UCHAR

DriveNumber

)

Definition at line 249 of file hwdisk.c.

{
    return PcDiskIdentifier[DriveNumber - 0x80];
}

Referenced by DetectBiosDisks().

GetHarddiskInformation()

static VOID GetHarddiskInformation ( UCHAR  DriveNumber )

static

Definition at line 255 of file hwdisk.c.

{
    PMASTER_BOOT_RECORD Mbr;
    PULONG Buffer;
    ULONG i;
    ULONG Checksum;
    ULONG Signature;
    BOOLEAN ValidPartitionTable;
    CHAR ArcName[MAX_PATH];
    PARTITION_TABLE_ENTRY PartitionTableEntry;
    PCHAR Identifier = PcDiskIdentifier[DriveNumber - 0x80];
 
    /* Detect disk partition type */
    DiskDetectPartitionType(DriveNumber);
 
    /* Read the MBR */
    if (!MachDiskReadLogicalSectors(DriveNumber, 0ULL, 1, DiskReadBuffer))
    {
        ERR("Reading MBR failed\n");
        /* We failed, use a default identifier */
        sprintf(Identifier, "BIOSDISK%d", DriveNumber - 0x80 + 1);
        return;
    }
 
    Buffer = (ULONG*)DiskReadBuffer;
    Mbr = (PMASTER_BOOT_RECORD)DiskReadBuffer;
 
    Signature = Mbr->Signature;
    TRACE("Signature: %x\n", Signature);
 
    /* Calculate the MBR checksum */
    Checksum = 0;
    for (i = 0; i < 512 / sizeof(ULONG); i++)
    {
        Checksum += Buffer[i];
    }
    Checksum = ~Checksum + 1;
    TRACE("Checksum: %x\n", Checksum);
 
    ValidPartitionTable = (Mbr->MasterBootRecordMagic == 0xAA55);
 
    /* Fill out the ARC disk block */
    sprintf(ArcName, "multi(0)disk(0)rdisk(%u)", DriveNumber - 0x80);
    AddReactOSArcDiskInfo(ArcName, Signature, Checksum, ValidPartitionTable);
 
    sprintf(ArcName, "multi(0)disk(0)rdisk(%u)partition(0)", DriveNumber - 0x80);
    FsRegisterDevice(ArcName, &DiskVtbl);
 
    /* Add partitions */
    i = 1;
    DiskReportError(FALSE);
    while (DiskGetPartitionEntry(DriveNumber, i, &PartitionTableEntry))
    {
        if (PartitionTableEntry.SystemIndicator != PARTITION_ENTRY_UNUSED)
        {
            sprintf(ArcName, "multi(0)disk(0)rdisk(%u)partition(%lu)", DriveNumber - 0x80, i);
            FsRegisterDevice(ArcName, &DiskVtbl);
        }
        i++;
    }
    DiskReportError(TRUE);
 
    /* Convert checksum and signature to identifier string */
    Identifier[0] = Hex[(Checksum >> 28) & 0x0F];
    Identifier[1] = Hex[(Checksum >> 24) & 0x0F];
    Identifier[2] = Hex[(Checksum >> 20) & 0x0F];
    Identifier[3] = Hex[(Checksum >> 16) & 0x0F];
    Identifier[4] = Hex[(Checksum >> 12) & 0x0F];
    Identifier[5] = Hex[(Checksum >> 8) & 0x0F];
    Identifier[6] = Hex[(Checksum >> 4) & 0x0F];
    Identifier[7] = Hex[Checksum & 0x0F];
    Identifier[8] = '-';
    Identifier[9] = Hex[(Signature >> 28) & 0x0F];
    Identifier[10] = Hex[(Signature >> 24) & 0x0F];
    Identifier[11] = Hex[(Signature >> 20) & 0x0F];
    Identifier[12] = Hex[(Signature >> 16) & 0x0F];
    Identifier[13] = Hex[(Signature >> 12) & 0x0F];
    Identifier[14] = Hex[(Signature >> 8) & 0x0F];
    Identifier[15] = Hex[(Signature >> 4) & 0x0F];
    Identifier[16] = Hex[Signature & 0x0F];
    Identifier[17] = '-';
    Identifier[18] = (ValidPartitionTable ? 'A' : 'X');
    Identifier[19] = 0;
    TRACE("Identifier: %s\n", Identifier);
}

Referenced by EnumerateHarddisks().

PcInitializeBootDevices()

BOOLEAN PcInitializeBootDevices

(

VOID

)

Definition at line 470 of file hwdisk.c.

{
    UCHAR DiskCount;
    BOOLEAN BootDriveReported = FALSE;
    ULONG i;
 
    DiskCount = EnumerateHarddisks(&BootDriveReported);
 
    /* Initialize FrLdrBootPath, the boot path we're booting from (the "SystemPartition") */
    DiskGetBootPath(PxeInit());
 
    /* Add it, if it's a floppy or cdrom */
    if ((FrldrBootDrive >= 0x80 && !BootDriveReported) ||
        DiskIsDriveRemovable(FrldrBootDrive))
    {
        /* TODO: Check if it's really a CDROM drive */
 
        PMASTER_BOOT_RECORD Mbr;
        PULONG Buffer;
        ULONG Checksum = 0;
        ULONG Signature;
 
        /* Read the MBR */
        if (!MachDiskReadLogicalSectors(FrldrBootDrive, 16ULL, 1, DiskReadBuffer))
        {
            ERR("Reading MBR failed\n");
            return FALSE;
        }
 
        Buffer = (ULONG*)DiskReadBuffer;
        Mbr = (PMASTER_BOOT_RECORD)DiskReadBuffer;
 
        Signature = Mbr->Signature;
        TRACE("Signature: %x\n", Signature);
 
        /* Calculate the MBR checksum */
        for (i = 0; i < 2048 / sizeof(ULONG); i++)
        {
            Checksum += Buffer[i];
        }
        Checksum = ~Checksum + 1;
        TRACE("Checksum: %x\n", Checksum);
 
        /* Fill out the ARC disk block */
        AddReactOSArcDiskInfo(FrLdrBootPath, Signature, Checksum, TRUE);
 
        FsRegisterDevice(FrLdrBootPath, &DiskVtbl);
        DiskCount++; // This is not accounted for in the number of pre-enumerated BIOS drives!
        TRACE("Additional boot drive detected: 0x%02X\n", (int)FrldrBootDrive);
    }
 
    return (DiskCount != 0);
}

Referenced by MachInit(), and Pc98InitializeBootDevices().

Variable Documentation

DiskReadBuffer

PVOID DiskReadBuffer

Definition at line 46 of file hwdisk.c.

Referenced by DiskRead(), EnumerateHarddisks(), GetHarddiskInformation(), and PcInitializeBootDevices().

DiskReadBufferSize

SIZE_T DiskReadBufferSize

Definition at line 47 of file hwdisk.c.

Referenced by DiskOpen(), DiskRead(), EnumerateHarddisks(), and PcMemFinalizeMemoryMap().

DiskVtbl

const DEVVTBL DiskVtbl

static

Initial value:

=
{
    DiskClose,
    DiskGetFileInformation,
    DiskOpen,
    DiskRead,
    DiskSeek,
}

Definition at line 238 of file hwdisk.c.

Referenced by GetHarddiskInformation(), and PcInitializeBootDevices().

Hex

const CHAR Hex[] = "0123456789abcdef"

static

Definition at line 40 of file hwdisk.c.

Referenced by GetHarddiskInformation().

PcBiosDiskCount

UCHAR PcBiosDiskCount = 0

Definition at line 43 of file hwdisk.c.

Referenced by DetectBiosDisks(), and EnumerateHarddisks().

PcDiskIdentifier

CHAR PcDiskIdentifier[32][20]

static

Definition at line 44 of file hwdisk.c.

Referenced by GetHarddiskIdentifier(), and GetHarddiskInformation().