enum {
	Maxtrack	= 200,
	Ntrack		= Maxtrack+1,
	BScdrom		= 2048,		/* mmc data block size */
	BScdda		= 2352,
	BScdxa		= 2336,
	BSmax		= 2352,

	Maxfeatures	= 512,

	/* scsi peripheral device types, SPC-3 §6.4.2 */
	TypeDA		= 0,		/* Direct Access (SBC) */
	TypeSA		= 1,		/* Sequential Access (SSC) */
	TypeWO		= 4,		/* Worm (SBC)*/
	TypeCD		= 5,		/* CD/DVD/BD (MMC) */
	TypeMO		= 7,		/* rewriteable Magneto-Optical (SBC) */
	TypeMC		= 8,		/* Medium Changer (SMC) */

	/* MMC device types */
	Mmcnone	= 0,
	Mmccd,
	Mmcdvdminus,
	Mmcdvdplus,
	Mmcbd,

	/* disc or track types */
	TypeNone	= 0,
	TypeAudio,
	TypeAwritable,
	TypeData,
	TypeDwritable,
	TypeDisk,
	TypeBlank,

	/* disc writability classes */
	Readonly	= 0,		/* -ROM */
	Write1,				/* -R: write once only */
	Erasewrite,			/* -R[WE]: erase then write */
	Ram,				/* -RAM: read & write unrestricted */

	/* tri-state flags */
	Unset		= -1,
	No,
	Yes,

	/* offsets in Pagcapmechsts mode page; see MMC-3 §5.5.10 */
	Capread		= 2,
	Capwrite	= 3,
	Capmisc		= 5,

	/* device capabilities in Pagcapmechsts mode page */
	Capcdr		= 1<<0,		/* bytes 2 & 3 */
	Capcdrw		= 1<<1,
	Captestwr	= 1<<2,
	Capdvdrom	= 1<<3,
	Capdvdr		= 1<<4,
	Capdvdram	= 1<<5,
	Capcdda		= 1<<0,		/* Capmisc bits */
	Caprw		= 1<<2,

	/* Pagwrparams mode page offsets */
	Wpwrtype	= 2,		/* write type */
	Wptrkmode,			/* track mode */
	Wpdatblktype,
	Wpsessfmt	= 8,
	Wppktsz		= 10,		/* BE ulong: # user data blks/fixed pkt */

	/* Pagwrparams bits */
	Bufe	= 1<<6,	/* Wpwrtype: buffer under-run free recording enable */
	/* Wptrkmode */
	Msbits	= 3<<6,		/* multisession field */
	Msnonext= 0<<6,		/* no next border nor session */
	Mscdnonext= 1<<6,	/* cd special: no next session */
	Msnext	= 3<<6,		/* next session or border allowed */
	Fp	= 1<<5,		/* pay attention to Wppktsz */

	/* close track session cdb bits */
	Closetrack	= 1,
	Closesessfinal	= 2,	/* close session / finalize disc */
	Closefinaldvdrw	= 3,	/* dvd-rw special: finalize */
	/* dvd+r dl special: close session, write extended lead-out */
	Closesessextdvdrdl = 4,
	Closefinal30mm	= 5,	/* dvd+r special: finalize with ≥30mm radius */
	Closedvdrbdfinal= 6,	/* dvd+r, bd-r special: finalize */

	/* read toc format values */
	Tocfmttoc	= 0,
	Tocfmtsessnos	= 1,
	Tocfmtqleadin	= 2,
	Tocfmtqpma	= 3,
	Tocfmtatip	= 4,
	Tocfmtcdtext	= 5,

	/* read toc cdb[1] bit */
	Msfbit	= 1<<1,

	/* write types, MMC-6 §7.5.4.9 */
	Wtpkt	= 0,		/* a.k.a. incremental */
	Wttrackonce,
	Wtsessonce,		/* a.k.a. disc-at-once */
	Wtraw,
	Wtlayerjump,

	/* track modes (determine: are these also track types?) */
	Tmcdda	= 0,		/* audio cdda */
	Tm2audio,		/* 2 audio channels */
	Tmunintr = 4,		/* data, recorded uninterrupted */
	Tmintr,			/* data, recorded interrupted (dvd default) */

	/* data block types */
	Dbraw = 0,		/* 2352 bytes */
	Db2kdata = 8,		/* mode 1: 2K of user data */
	Db2336,			/* mode 2: 2336 bytes of user data */

	/* session formats */
	Sfdata	= 0,
	Sfcdi	= 0x10,
	Sfcdxa	= 0x20,

	/* Cache control bits in mode page 8 byte 2 */
	Ccrcd	= 1<<0,		/* read cache disabled */
	Ccmf	= 1<<1,		/* multiplication factor */
	Ccwce	= 1<<2,		/* writeback cache enabled */
	Ccsize	= 1<<3, /* use `cache segment size', not `# of cache segments' */
	Ccdisc	= 1<<4,		/* discontinuity */
	Cccap	= 1<<5,		/* caching analysis permitted */
	Ccabpf	= 1<<6,		/* abort pre-fetch */
	Ccic	= 1<<7,		/* initiator control */

	/* drive->cap bits */
	Cwrite	= 1<<0,
	Ccdda	= 1<<1,

	CDNblock = 12,		/* chosen for CD */
	DVDNblock = 16,		/* DVD ECC block is 16 sectors */
	BDNblock = 32,		/* BD ECC block (`cluster') is 32 sectors */
				/* BD-R are write-once in increments of 64KB */
	/*
	 * make a single transfer fit in a 9P rpc.  if we don't do this,
	 * remote access (e.g., via /mnt/term/dev/sd*) fails mysteriously.
	 */
	Readblock = 8192/BScdrom,
};

typedef struct Buf Buf;
typedef struct Dev Dev;
typedef struct Drive Drive;
typedef struct Msf Msf;		/* minute, second, frame */
typedef struct Otrack Otrack;
typedef struct Track Track;
typedef schar Tristate;

struct Msf {
	int	m;
	int	s;
	int	f;
};

struct Track
{
	/* initialized while obtaining the toc (gettoc) */
	vlong	size;		/* total size in bytes */
	long	bs;		/* block size in bytes */
	ulong	beg;		/* beginning block number */
	ulong	end;		/* ending block number */
	int	type;
	Msf	mbeg;
	Msf	mend;

	/* initialized by fs */
	char	name[32];
	int	mode;
	ulong	mtime;
};

struct DTrack			/* not used */
{
	uchar	name[32];
	uchar	beg[4];		/* msf value; only used for audio */
	uchar	end[4];		/* msf value; only used for audio */
	uchar	size[8];
	uchar	magic[4];
};

struct Otrack
{
	Track	*track;
	Drive	*drive;
	int	nchange;
	int	omode;
	Buf	*buf;

	int	nref;		/* kept by file server */
};

struct Dev
{
	Otrack*	(*openrd)(Drive *d, int trackno);
	Otrack*	(*create)(Drive *d, int bs);
	long	(*read)(Otrack *t, void *v, long n, vlong off);
	long	(*write)(Otrack *t, void *v, long n);
	void	(*close)(Otrack *t);
	int	(*gettoc)(Drive*);
	int	(*fixate)(Drive *d);
	char*	(*ctl)(Drive *d, int argc, char **argv);
	char*	(*setspeed)(Drive *d, int r, int w);
};

struct Drive
{
	QLock;
	Scsi;

	int	type;			/* scsi peripheral device type: Type?? */

	/* disc characteristics */
	int	mmctype;		/* cd, dvd, or bd */
	char	*dvdtype;		/* name of dvd flavour */
	char	*laysfx;		/* layer suffix (e.g., -dl) */
	int	firsttrack;
	int	invistrack;
	int	ntrack;
	int	nchange;		/* compare with the members in Scsi */
	ulong	changetime;		/* " */
	int	relearn;		/* need to re-learn the disc? */
	int	nameok;
	int	writeok;		/* writable disc? */
	/*
	 * we could combine these attributes into a single variable except
	 * that we discover them separately sometimes.
	 */
	Tristate recordable;		/* writable by burning? */
	Tristate erasable;		/* writable after erasing? */

	Track	track[Ntrack];
	ulong	end;			/* # of blks on current disc */
	ulong	cap;			/* drive capabilities */
	uchar	blkbuf[BScdda];

	int	maxreadspeed;
	int	maxwritespeed;
	int	readspeed;
	int	writespeed;
	Dev;

	uchar	features[Maxfeatures/8];

	void *aux;		/* kept by driver */
};

struct Buf
{
	uchar	*data;		/* buffer */
	vlong	off;		/* data[0] at offset off in file */
	int	bs;		/* block size */
	long	ndata;		/* no. valid bytes in data */
	int	nblock;		/* total buffer size in blocks */
	int	omode;		/* OREAD, OWRITE */
	long	(*fn)(Buf*, void*, long, ulong); /* read, write */

	/* used only by client */
	Otrack	*otrack;
};

extern int	vflag;