NetBSD/sys/msdosfs/fat.h

60 lines
2.2 KiB
C

/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*
* $Id: fat.h,v 1.1 1993/08/13 11:35:33 cgd Exp $
*/
/*
* Some useful cluster numbers.
*/
#define MSDOSFSROOT 0 /* cluster 0 means the root dir */
#define CLUST_FREE 0 /* cluster 0 also means a free cluster */
#define MSDOSFSFREE CLUST_FREE
#define CLUST_FIRST 2 /* first legal cluster number */
#define CLUST_RSRVS 0xfff0 /* start of reserved cluster range */
#define CLUST_RSRVE 0xfff6 /* end of reserved cluster range */
#define CLUST_BAD 0xfff7 /* a cluster with a defect */
#define CLUST_EOFS 0xfff8 /* start of eof cluster range */
#define CLUST_EOFE 0xffff /* end of eof cluster range */
#define FAT12_MASK 0x0fff /* mask for 12 bit cluster numbers */
#define FAT16_MASK 0xffff /* mask for 16 bit cluster numbers */
/*
* Return true if filesystem uses 12 bit fats. Microsoft Programmer's
* Reference says if the maximum cluster number in a filesystem is greater
* than 4086 then we've got a 16 bit fat filesystem.
*/
#define FAT12(pmp) (pmp->pm_maxcluster <= 4086)
#define FAT16(pmp) (pmp->pm_maxcluster > 4086)
#define MSDOSFSEOF(cn) (((cn) & 0xfff8) == 0xfff8)
/*
* These are the values for the function argument to the function
* fatentry().
*/
#define FAT_GET 0x0001 /* get a fat entry */
#define FAT_SET 0x0002 /* set a fat entry */
#define FAT_GET_AND_SET (FAT_GET | FAT_SET)
#if defined(KERNEL)
int pcbmap __P((struct denode * dep, u_long findcn, daddr_t * bnp, u_long * cnp));
int clusterfree __P((struct msdosfsmount * pmp, u_long cn, u_long * oldcnp));
int clusteralloc __P((struct msdosfsmount * pmp, u_long * retcluster, u_long fillwith));
int fatentry __P((int function, struct msdosfsmount * pmp, u_long cluster, u_long * oldcontents, u_long newcontents));
int freeclusterchain __P((struct msdosfsmount * pmp, u_long startchain));
#endif /* defined(KERNEL) */