diff --git a/main.c b/main.c
index 6ef8da1..d467217 100644
--- a/main.c
+++ b/main.c
@@ -20,7 +20,7 @@ void
 main0(void)
 {
   int i;
-  static int bcpu;  // cannot be on stack
+  static volatile int bcpu;  // cannot be on stack
 
   // clear BSS
   memset(edata, 0, end - edata);
@@ -32,7 +32,7 @@ main0(void)
   mp_init(); // collect info about this machine
   bcpu = mp_bcpu();
 
-  // switch to bootstrap processor's stack
+  // Switch to bootstrap processor's stack
   asm volatile("movl %0, %%esp" : : "r" (cpus[bcpu].mpstack+MPSTACK-32));
   asm volatile("movl %0, %%ebp" : : "r" (cpus[bcpu].mpstack+MPSTACK));
 
@@ -72,14 +72,10 @@ void
 mpmain(void)
 {
   cprintf("cpu%d: starting\n", cpu());
-  idtinit(); // CPU's idt
-  if(cpu() == 0)
-    panic("mpmain on cpu 0");
+  idtinit();
   lapic_init(cpu());
   lapic_timerinit();
   lapic_enableintr();
-
-  // make sure there's a TSS
   setupsegs(0);
 
   cpuid(0, 0, 0, 0, 0);  // memory barrier