scemu/main.c

#include <u.h>
#include <libc.h>
#include "dat.h"
#include "fns.h"

void
usage(void)
{
	fprint(2, "usage: %s [ -t ] [ -s target cycle length ] prog\n", argv0);
	exits("usage");
}

void
openprog(char *f)
{
	int fd;
	long n;
	Dir *d;
	usize s;

	fd = open(f, OREAD);
	if(fd < 0)
		sysfatal("cannot open program: %r");
	d = dirfstat(fd);
	if(d->length > 0xFF00)
		sysfatal("program too big: cannot be bigger than $ff00");
	romptr = mem+32768;
	romptr += 32768 - d->length;
	s = mem+65536-romptr;
	free(d);
	n = read(fd, romptr, s);
	if(n != s)
		fprint(2, "tried to read %ulld bytes, got %ld bytes\n", s, n);
	close(fd);
}

void
main(int argc, char **argv)
{
	int c;
	vlong t, t2, t3;
	vlong target;

	trace = 0;
	target = 1000;
	mem = malloc(0x10000);
	if(mem == nil)
		sysfatal("bad malloc for mem");
	ARGBEGIN{
	case 's':
		target = atoll(EARGF(usage()));
		break;
	case 't':
		trace = 1;
		break;
	default:
		usage();
		break;
	}ARGEND
	if(!argc)
		usage();
	openprog(*argv);
	rP = 0x34;
	pc = 0xFFFC;
	pc = fetch16();
	for(;;){
		c = step();
		while(c >= 0){
			t = nsec();
			--c;
			t2 = nsec();
			t3 = t2-t;
			while(t3 < target){
				t2 = nsec();
				t3 = t2-t;
			}
		}
		out();
	}
}