#include <u.h>#include <libc.h>#include <tos.h> /* * nsec() is wallclock and can be adjusted by timesync * so need to use cycles() instead, but fall back to * nsec() in case we can't */uvlongclock(void){	static uvlong fasthz, xstart;	uvlong x, div; 	if(fasthz == ~0ULL)		return nsec() - xstart; 	if(fasthz == 0){		if((fasthz = _tos->cyclefreq) == 0){			fasthz = ~0ULL;			xstart = nsec();			fprint(2, "cyclefreq not available, falling back to nsec()\n");			fprint(2, "you might want to disable aux/timesync\n");			return 0;		}else{			cycles(&xstart);		}	}	cycles(&x);	x -= xstart; 	/* this is ugly */	for(div = 1000000000ULL; x < 0x1999999999999999ULL && div > 1 ; div /= 10ULL, x *= 10ULL); 	return x / (fasthz / div);}