#include <u.h>#include <libc.h> char *datac[] = {0,"#P/iob","#P/iow",0,"#P/iol",0,0,0,"#P/msr"};char *file; voidusage(void){	fprint(2, "%s: [-f file] [ -WLME ] [-r | -w] address [ value ] [ mask ]\n", argv0);	exits("usage");} voidmain(int argc, char** argv) {	int fd, size, op;	ulong port;	uvlong data, value, mask;	uchar datab[8];		data = value = mask = 0;	size = 1;	op = -1;	ARGBEGIN {		case 'f': file = EARGF(usage()); break;		case 'W': size = 2; break;		case 'L': size = 4; break;		case 'M': size = 8; break;		case 'E': datac[1] = datac[2] = datac[4] = datac[8] = "#P/ec"; break;		case 'r': op = OREAD; break;		case 'w': op = OWRITE; break;		default: usage();	} ARGEND;	if(op == -1) usage();	if(argc < 1) usage();	port = strtoul(*argv, 0, 0);	argv++, argc--;	if(op == OWRITE) {		if(argc < 1) usage();		value = strtoull(*argv, 0, 0);		argv++, argc--;	}	if(argc > 0){		mask = ~strtoull(*argv, 0, 0);		argv++, argc--;		if(op == OWRITE){			op = ORDWR;			value &= ~mask;		}	}  	if(op == OREAD)		mask = ~mask;	USED(argv);	if(argc != 0) usage();	fd = open(file==nil?datac[size]:file, op);	if(fd == -1) sysfatal("open: %r");	if(op == OREAD || op == ORDWR) {		memset(datab, 0, 8);		if(pread(fd, datab, size, port) != size)			sysfatal("pread: %r");		data = datab[0] | (datab[1] << 8) | (datab[2] << 16) |			(datab[3] << 24) | ((uvlong)datab[4] << 32) |			((uvlong)datab[5] << 40) | ((uvlong)datab[6] << 48) | 			((uvlong)datab[7] << 56);		data &= mask;	}	if(op == OWRITE || op == ORDWR) {		data |= value;		datab[0] = data;		datab[1] = data >> 8;		datab[2] = data >> 16;		datab[3] = data >> 24;		datab[4] = data >> 32;		datab[5] = data >> 40;		datab[6] = data >> 48;		datab[7] = data >> 56;		if(pwrite(fd, datab, size, port) != size)			sysfatal("pwrite: %r");	}	print("0x%ullx\n", data);	exits(nil);}