typedef struct Cursor Cursor;typedef struct Cursorinfo Cursorinfo;struct Cursorinfo {	Cursor;	Lock;}; /* devmouse.c */extern void mousetrack(int, int, int, int);extern Point mousexy(void); extern void mouseaccelerate(int);extern int m3mouseputc(Queue*, int);extern int m5mouseputc(Queue*, int);extern int mouseputc(Queue*, int); extern Cursorinfo cursor;extern Cursor arrow; /* * Generic VGA registers. */enum {	MiscW		= 0x03C2,	/* Miscellaneous Output (W) */	MiscR		= 0x03CC,	/* Miscellaneous Output (R) */	Status0		= 0x03C2,	/* Input status 0 (R) */	Status1		= 0x03DA,	/* Input Status 1 (R) */	FeatureR	= 0x03CA,	/* Feature Control (R) */	FeatureW	= 0x03DA,	/* Feature Control (W) */ 	Seqx		= 0x03C4,	/* Sequencer Index, Data at Seqx+1 */	Crtx		= 0x03D4,	/* CRT Controller Index, Data at Crtx+1 */	Grx		= 0x03CE,	/* Graphics Controller Index, Data at Grx+1 */	Attrx		= 0x03C0,	/* Attribute Controller Index and Data */ 	PaddrW		= 0x03C8,	/* Palette Address Register, write */	Pdata		= 0x03C9,	/* Palette Data Register */	Pixmask		= 0x03C6,	/* Pixel Mask Register */	PaddrR		= 0x03C7,	/* Palette Address Register, read */	Pstatus		= 0x03C7,	/* DAC Status (RO) */ 	Pcolours	= 256,		/* Palette */	Pred		= 0,	Pgreen		= 1,	Pblue		= 2, 	Pblack		= 0x00,	Pwhite		= 0xFF,}; #define VGAMEM()	0xA0000#define vgai(port)		inb(port)#define vgao(port, data)	outb(port, data) extern int vgaxi(long, uchar);extern int vgaxo(long, uchar, uchar); /* */typedef struct VGAdev VGAdev;typedef struct VGAcur VGAcur;typedef struct VGAscr VGAscr; struct VGAdev {	char*	name; 	void	(*enable)(VGAscr*);	void	(*disable)(VGAscr*);	void	(*page)(VGAscr*, int);	void	(*linear)(VGAscr*, int, int);	void	(*drawinit)(VGAscr*);	int	(*fill)(VGAscr*, Rectangle, ulong);	void	(*ovlctl)(VGAscr*, Chan*, void*, int);	int	(*ovlwrite)(VGAscr*, void*, int, vlong);	void (*flush)(VGAscr*, Rectangle);}; struct VGAcur {	char*	name; 	void	(*enable)(VGAscr*);	void	(*disable)(VGAscr*);	void	(*load)(VGAscr*, Cursor*);	int	(*move)(VGAscr*, Point); 	int	doespanning;}; /* */struct VGAscr {	Lock	devlock;	VGAdev*	dev;	Pcidev*	pci; 	VGAcur*	cur;	uintptr	storage;				/* storage size (?) */	Cursor; 	int	useflush; 	uintmem	paddr;				/* frame buffer */	void*	vaddr;	int	apsize; 	uintmem	io;				/* device specific registers */	u32int	*mmio;		ulong	colormap[Pcolours][3];	int	palettedepth; 	Memimage*	gscreen;	Memdata*	gscreendata;	Memsubfont*	memdefont; 	int	(*fill)(VGAscr*, Rectangle, ulong);	int	(*scroll)(VGAscr*, Rectangle, Rectangle);	void	(*blank)(VGAscr*, int);	uint	id;	/* internal identifier for driver use */	int	isblank;	int	overlayinit;}; extern VGAscr vgascreen[]; enum {	Backgnd		= 0,	/* black */}; /* mouse.c */extern	void	mousectl(Cmdbuf*);extern	void	mouseresize(void);extern	void	mouseredraw(void); /* screen.c */extern	int	hwaccel;	/* use hw acceleration; default on */extern	int	hwblank;	/* use hw blanking; default on */extern	int	panning;	/* use virtual screen panning; default off */extern	void	addvgaseg(char*, uintmem, usize);extern	uchar*	attachscreen(Rectangle*, ulong*, int*, int*, int*);extern	void	flushmemscreen(Rectangle);extern	void	cursoron(void);extern	void	cursoroff(void);extern	void	setcursor(Cursor*);extern	int	screensize(int, int, int, ulong);extern	int	screenaperture(int, int);extern	Rectangle physgscreenr;	/* actual monitor size */extern	void	blankscreen(int);extern	int	setcolor(ulong, ulong, ulong, ulong);extern	void	getcolor(ulong, ulong*, ulong*, ulong*); extern	VGAcur	swcursor; /* devdraw.c */extern	void	deletescreenimage(void);extern	void	resetscreenimage(void);extern	int	drawhasclients(void);extern	ulong	blanktime;extern	void	setscreenimageclipr(Rectangle);extern	void	drawflush(void);extern	int	drawidletime(void);extern	QLock	drawlock; /* vga.c */extern	void	vgascreenwin(VGAscr*);extern	void	vgaimageinit(ulong);extern	void	vgalinearpciid(VGAscr*, int, int);extern	void	vgalinearpci(VGAscr*);extern	void	vgalinearaddr(VGAscr*, uintmem, usize); extern	void	drawblankscreen(int);extern	void	vgablank(VGAscr*, int); extern	Lock	vgascreenlock; #define ishwimage(i)	(vgascreen[0].gscreendata && (i)->data->bdata == vgascreen[0].gscreendata->bdata) /* swcursor.c */void		swcursorhide(void);void		swcursoravoid(Rectangle);void		swcursordraw(Point);void		swcursorload(Cursor *);void		swcursorinit(void);