Don't enable interrupts prior to IVT and PIC setup

The machine may crash if an interrupt occurs prior to the setup of the
interrupt vector table (IVT) and programmable interrupt controller
(PIC).  This patch makes sure that interrupts remain disabled until
these components are setup.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 8 insertions, 5 deletions

diff --git a/src/stacks.c b/src/stacks.c
index 1dbdfe9b..1ad9ef09 100644
--- a/src/stacks.c
+++ b/src/stacks.c
@@ -558,12 +558,13 @@ getCurThread(void)
     return (void*)ALIGN_DOWN(esp, THREADSTACKSIZE);
 }
 
-static int ThreadControl;
+static u8 CanInterrupt, ThreadControl;
 
 // Initialize the support for internal threads.
 void
-thread_init(void)
+thread_setup(void)
 {
+    CanInterrupt = 1;
     if (! CONFIG_THREADS)
         return;
     ThreadControl = romfile_loadint("etc/threads", 1);
@@ -673,11 +674,12 @@ void
 yield(void)
 {
     if (MODESEGMENT || !CONFIG_THREADS) {
-        check_irqs();
+        if (MODESEGMENT || CanInterrupt)
+            check_irqs();
         return;
     }
     struct thread_info *cur = getCurThread();
-    if (cur == &MainThread)
+    if (cur == &MainThread && CanInterrupt)
         // Permit irqs to fire
         check_irqs();
 
@@ -705,7 +707,8 @@ yield_toirq(void)
         yield();
         return;
     }
-    wait_irq();
+    if (MODESEGMENT || CanInterrupt)
+        wait_irq();
 }
 
 // Wait for all threads (other than the main thread) to complete.