View of xos/fs/vfat_fat_info.h

/* Copyright (C) 2008  Emmanuel Varoquaux
 
   This file is part of XOS.
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 
/* Implementation des macros definis dans le document 'FAT: General Overview of
 * On-Disk Format' (Microsoft Extensible Firmware Initiative - FAT32 File
 * System Specification). *
 * Les conventions de nommage definies dans ce document ont ete conservees. */
 
#ifndef VFAT_FAT_INFO_H
#define VFAT_FAT_INFO_H
 
#define FALSE 0
#define TRUE  1
 
#include "vfat_fat_info_struct.h"
 
typedef unsigned short WORD;
typedef unsigned long DWORD;
 
/* types de FAT */
enum {FAT12, FAT16, FAT32};
 
int init_fat_info(struct vfat_fat_info_struct *fat_info, const void *buf);
 
static inline unsigned long FirstSectorofCluster(const struct vfat_fat_info_struct *fat_info, unsigned long N)
{
  return ((N - 2) * fat_info->boot_sect.BPB_SecPerClus) + fat_info->FirstDataSector;
}
 
static inline unsigned long FATOffset(const struct vfat_fat_info_struct *fat_info, unsigned long N)
{
  if (fat_info->FATType == FAT12)
    return N + (N / 2);
  else if (fat_info->FATType == FAT16)
    return N * 2;
  else
    return N * 4;
}
 
static inline unsigned long ThisFATSecNum(const struct vfat_fat_info_struct *fat_info, unsigned long N)
{
  return fat_info->boot_sect.BPB_ResvdSecCnt + (FATOffset(fat_info, N) / fat_info->boot_sect.BPB_BytsPerSec);
}
 
static inline unsigned long ThisFATEntOffset(const struct vfat_fat_info_struct *fat_info, unsigned long N)
{
  return FATOffset(fat_info, N) % fat_info->boot_sect.BPB_BytsPerSec;
}
 
unsigned long get_FATClusEntryVal(const unsigned char SecBuff[], const struct vfat_fat_info_struct *fat_info, unsigned long N);
 
void set_FATClusEntryVal(unsigned char SecBuff[], const struct vfat_fat_info_struct *fat_info, unsigned long N, unsigned long FATClusEntryVal);
 
int IsEOF(const struct vfat_fat_info_struct *fat_info, unsigned long FATContent);
 
#endif