vfdfat.c File Reference

#include <windows.h>
#include "vfdtypes.h"
#include "vfdio.h"
#include "vfdlib.h"
#include "vfdver.h"

Include dependency graph for vfdfat.c:

Go to the source code of this file.

Classes
struct	_DOS_BPB
struct	_EXBPB
struct	_DOS_PBR

Macros
#define	WIN32_LEAN_AND_MEAN
#define	FAT_DIR_ENTRY_SIZE   32
#define	VFD_JUMP_CODE   "\xeb\x3c\x90"
#define	VFD_OEM_NAME   "VFD" VFD_DRIVER_VERSION_STR " "
#define	VFD_VOLUME_LABEL   "NO NAME "
#define	VFD_FILESYSTEM   "FAT12 "

Typedefs
typedef struct _DOS_BPB	DOS_BPB
typedef struct _DOS_BPB *	PDOS_BPB
typedef struct _EXBPB	EXBPB
typedef struct _EXBPB *	PEXBPB
typedef struct _DOS_PBR	DOS_PBR
typedef struct _DOS_PBR *	PDOS_PBR

Functions
static const DOS_BPB *	SelectDosBpb (USHORT nSectors)
DWORD	FormatBufferFat (PUCHAR pBuffer, ULONG nSectors)

Macro Definition Documentation

FAT_DIR_ENTRY_SIZE

#define FAT_DIR_ENTRY_SIZE   32

Definition at line 71 of file vfdfat.c.

VFD_FILESYSTEM

#define VFD_FILESYSTEM   "FAT12 "

Definition at line 78 of file vfdfat.c.

VFD_JUMP_CODE

#define VFD_JUMP_CODE   "\xeb\x3c\x90"

Definition at line 75 of file vfdfat.c.

VFD_OEM_NAME

#define VFD_OEM_NAME   "VFD" VFD_DRIVER_VERSION_STR " "

Definition at line 76 of file vfdfat.c.

VFD_VOLUME_LABEL

#define VFD_VOLUME_LABEL   "NO NAME "

Definition at line 77 of file vfdfat.c.

WIN32_LEAN_AND_MEAN

#define WIN32_LEAN_AND_MEAN

Definition at line 15 of file vfdfat.c.

Typedef Documentation

DOS_BPB

typedef struct _DOS_BPB DOS_BPB

DOS_PBR

typedef struct _DOS_PBR DOS_PBR

EXBPB

typedef struct _EXBPB EXBPB

PDOS_BPB

typedef struct _DOS_BPB * PDOS_BPB

PDOS_PBR

typedef struct _DOS_PBR * PDOS_PBR

PEXBPB

typedef struct _EXBPB * PEXBPB

Function Documentation

FormatBufferFat()

DWORD FormatBufferFat	(	PUCHAR	pBuffer,
		ULONG	nSectors
	)

Definition at line 116 of file vfdfat.c.

{
    const DOS_BPB   *bpb;   // BIOS Parameter Block
    PDOS_PBR        pbr;    // Partition Boot Record
    PUCHAR          fat;    // File Allocation Table
    USHORT          idx;
 
    VFDTRACE(0,
        ("[VFD] VfdFormatImage - IN\n"));
 
    //
    //  Select DOS BPB parameters from media size
    //
    bpb = SelectDosBpb((USHORT)nSectors);
 
    if (!bpb) {
        VFDTRACE(0,
            ("[VFD] Unsupported media size %lu\n",
            nSectors));
        return ERROR_INVALID_PARAMETER;
    }
 
    //
    //  Initialize the whole area with the fill data
    //
    FillMemory(pBuffer,
        VFD_SECTOR_TO_BYTE(nSectors),
        VFD_FORMAT_FILL_DATA);
 
    //
    //  Make up the FAT boot record
    //
    ZeroMemory(pBuffer, VFD_BYTES_PER_SECTOR);
 
    pbr = (PDOS_PBR)pBuffer;
 
    CopyMemory(pbr->jump,   VFD_JUMP_CODE,  sizeof(pbr->jump));
    CopyMemory(pbr->oemid,  VFD_OEM_NAME,   sizeof(pbr->oemid));
    CopyMemory(&pbr->bpb,   bpb,            sizeof(pbr->bpb));
 
    //  Make up the extended BPB
 
    pbr->exbpb.BootSignature        = 0x29;
 
    //  use the tick count as the volume serial number
    pbr->exbpb.VolumeSerialNumber   = GetTickCount();
 
    CopyMemory(pbr->exbpb.VolumeLabel,
        VFD_VOLUME_LABEL, sizeof(pbr->exbpb.VolumeLabel));
 
    CopyMemory(pbr->exbpb.FileSystemType,
        VFD_FILESYSTEM, sizeof(pbr->exbpb.FileSystemType));
 
    //  Set the boot record signature
 
    *(pBuffer + VFD_BYTES_PER_SECTOR - 2) = 0x55;
    *(pBuffer + VFD_BYTES_PER_SECTOR - 1) = 0xaa;
 
    //
    //  Clear FAT areas
    //
    fat = pBuffer + VFD_SECTOR_TO_BYTE(bpb->ReservedSectors);
 
    ZeroMemory(
        fat,
        VFD_SECTOR_TO_BYTE(bpb->SectorsPerFAT * bpb->NumberOfFATs));
 
    //
    //  Make up FAT entries for the root directory
    //
    for (idx = 0; idx < bpb->NumberOfFATs; idx++) {
        *fat = bpb->MediaDescriptor;
        *(fat + 1) = 0xff;
        *(fat + 2) = 0xff;
 
        fat += VFD_SECTOR_TO_BYTE(bpb->SectorsPerFAT);
    }
 
    //
    //  Clear root directory entries
    //
    ZeroMemory(fat, bpb->RootEntries * FAT_DIR_ENTRY_SIZE);
 
    VFDTRACE(0,
        ("[VFD] VfdFormatImage - OUT\n"));
 
    return ERROR_SUCCESS;
}

Referenced by VfdCreateImageFile(), VfdFormatMedia(), and VfdOpenImage().

SelectDosBpb()

static const DOS_BPB * SelectDosBpb ( USHORT  nSectors )

static

Definition at line 83 of file vfdfat.c.

{
    static const DOS_BPB bpb_tbl[] = {
        // b/s                s/c r fat root  sec  desc s/f s/t  h
        {VFD_BYTES_PER_SECTOR, 2, 1, 2, 112,  320, 0xFE,  1,  8, 1, 0, 0},  // 160KB 5.25"
        {VFD_BYTES_PER_SECTOR, 2, 1, 2, 112,  360, 0xFC,  1,  9, 1, 0, 0},  // 180KB 5.25"
        {VFD_BYTES_PER_SECTOR, 2, 1, 2, 112,  640, 0xFF,  1,  8, 2, 0, 0},  // 320KB 5.25"
        {VFD_BYTES_PER_SECTOR, 2, 1, 2, 112,  720, 0xFD,  2,  9, 2, 0, 0},  // 360KB 5.25"
        {VFD_BYTES_PER_SECTOR, 2, 1, 2, 112, 1280, 0xFB,  2,  8, 2, 0, 0},  // 640KB 5.25" / 3.5"
        {VFD_BYTES_PER_SECTOR, 2, 1, 2, 112, 1440, 0xF9,  3,  9, 2, 0, 0},  // 720KB 5.25" / 3.5"
        {VFD_BYTES_PER_SECTOR, 2, 1, 2, 112, 1640, 0xF9,  3, 10, 2, 0, 0},  // 820KB 3.5"
        {VFD_BYTES_PER_SECTOR, 1, 1, 2, 224, 2400, 0xF9,  7, 15, 2, 0, 0},  // 1.20MB 5.25" / 3.5"
        {VFD_BYTES_PER_SECTOR, 1, 1, 2, 224, 2880, 0xF0,  9, 18, 2, 0, 0},  // 1.44MB 3.5"
        {VFD_BYTES_PER_SECTOR, 1, 1, 2, 224, 3360, 0xF0, 10, 21, 2, 0, 0},  // 1.68MB 3.5"
        {VFD_BYTES_PER_SECTOR, 1, 1, 2, 224, 3444, 0xF0, 10, 21, 2, 0, 0},  // 1.72MB 3.5"
        {VFD_BYTES_PER_SECTOR, 2, 1, 2, 240, 5760, 0xF0,  9, 36, 2, 0, 0},  // 2.88MB 3.5"
    };
 
    int i;
 
    for (i = 0; i < sizeof(bpb_tbl) / sizeof(bpb_tbl[0]); i++) {
        if (nSectors == bpb_tbl[i].SmallSectors) {
            return &bpb_tbl[i];
        }
    }
 
    return NULL;
}

Referenced by FormatBufferFat().