#include "u.h"#include "../port/lib.h"#include "mem.h"#include "dat.h"#include "fns.h"#include "../port/error.h" #define	Image	IMAGE#include <draw.h>#include <memdraw.h>#include <cursor.h>#include "screen.h" static Lock vgaxlock;			/* access to index registers */ intvgaxi(long port, uchar index){	uchar data; 	ilock(&vgaxlock);	switch(port){ 	case Seqx:	case Crtx:	case Grx:		outb(port, index);		data = inb(port+1);		break; 	case Attrx:		/*		 * Allow processor access to the colour		 * palette registers. Writes to Attrx must		 * be preceded by a read from Status1 to		 * initialise the register to point to the		 * index register and not the data register.		 * Processor access is allowed by turning		 * off bit 0x20.		 */		inb(Status1);		if(index < 0x10){			outb(Attrx, index);			data = inb(Attrx+1);			inb(Status1);			outb(Attrx, 0x20|index);		}		else{			outb(Attrx, 0x20|index);			data = inb(Attrx+1);		}		break; 	default:		iunlock(&vgaxlock);		return -1;	}	iunlock(&vgaxlock); 	return data & 0xFF;} intvgaxo(long port, uchar index, uchar data){	ilock(&vgaxlock);	switch(port){ 	case Seqx:	case Crtx:	case Grx:		/*		 * We could use an outport here, but some chips		 * (e.g. 86C928) have trouble with that for some		 * registers.		 */		outb(port, index);		outb(port+1, data);		break; 	case Attrx:		inb(Status1);		if(index < 0x10){			outb(Attrx, index);			outb(Attrx, data);			inb(Status1);			outb(Attrx, 0x20|index);		}		else{			outb(Attrx, 0x20|index);			outb(Attrx, data);		}		break; 	default:		iunlock(&vgaxlock);		return -1;	}	iunlock(&vgaxlock); 	return 0;}