from richard, allow multiprocessing to start

Reference: /n/atom/patch/applied/pimp
Date: Mon Jan  4 16:29:32 CET 2016
Signed-off-by: quanstro@quanstro.net

--- /sys/src/9/bcm/main.c	Mon Jan  4 16:29:23 2016
+++ /sys/src/9/bcm/main.c	Mon Jan  4 16:29:25 2016
@@ -246,6 +246,8 @@
 void
 mach0init(void)
 {
+	conf.nmach = 0;
+
 	m->machno = 0;
 	machaddr[m->machno] = m;
 
@@ -556,9 +558,6 @@
 	conf.upages = (conf.npage*80)/100;
 	conf.ialloc = ((conf.npage-conf.upages)/2)*BY2PG;
 
-	/* only one processor */
-	conf.nmach = 1;
-
 	/* set up other configuration parameters */
 	conf.nproc = 100 + ((conf.npage*BY2PG)/MB)*5;
 	if(cpuserver)
@@ -569,7 +568,7 @@
 	conf.nswppo = 4096;
 	conf.nimage = 200;
 
-	conf.copymode = 0;		/* copy on write */
+	conf.copymode = 1;		/* copy on reference, not copy on write */
 
 	/*
 	 * Guess how much is taken by the large permanent