Keep interrupts disabled during startup.

1 files changed, 27 insertions, 16 deletions

diff --git a/main.c b/main.c
index 63e8e35..3f2d57a 100644
--- a/main.c
+++ b/main.c
@@ -11,36 +11,30 @@
 #include "spinlock.h"
 
 extern char edata[], end[];
-extern int acpu;
 extern uint8_t _binary_user1_start[], _binary_user1_size[];
 extern uint8_t _binary_usertests_start[], _binary_usertests_size[];
 extern uint8_t _binary_userfs_start[], _binary_userfs_size[];
 
 extern int use_console_lock;
 
-struct spinlock sillylock;  // hold this to keep interrupts disabled
-
+// CPU 0 starts running C code here.
 int
 main()
 {
+  int i;
   struct proc *p;
 
-  if (acpu) {
-    cprintf("an application processor\n");
-    idtinit(); // CPU's idt
-    lapic_init(cpu());
-    lapic_timerinit();
-    lapic_enableintr();
-    scheduler();
-  }
-  acpu = 1;
-
   // clear BSS
   memset(edata, 0, end - edata);
 
+  // Make sure interrupts stay disabled on all processors
+  // until each signals it is ready, by pretending to hold
+  // an extra lock.
+  for(i=0; i<NCPU; i++)
+    cpus[i].nlock++;
+
   mp_init(); // collect info about this machine
 
-  acquire(&sillylock);
   use_console_lock = 1;
 
   lapic_init(mp_bcpu());
@@ -78,7 +72,8 @@ main()
   // init disk device
   //ide_init(); 
 
-  // become interruptable
+  // Enable interrupts on this processor.
+  cpus[cpu()].nlock--;
   sti();
 
   p = copyproc(&proc[0]);
@@ -87,13 +82,29 @@ main()
   //load_icode(p, _binary_userfs_start, (unsigned) _binary_userfs_size);
   p->state = RUNNABLE;
   cprintf("loaded userfs\n");
-  release(&sillylock);
 
   scheduler();
 
   return 0;
 }
 
+// Additional processors start here.
+int 
+mpmain(void)
+{
+  cprintf("an application processor\n");
+  idtinit(); // CPU's idt
+  lapic_init(cpu());
+  lapic_timerinit();
+  lapic_enableintr();
+
+  // Enable interrupts on this processor.
+  cpus[cpu()].nlock--;
+  sti();
+
+  scheduler();
+}
+
 void
 load_icode(struct proc *p, uint8_t *binary, unsigned size)
 {