X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Finterrupt.c;h=c886cc9d709ab71a3c4bc870eb758ea92321b1a5;hb=5f1b986185717577aac1922544cb3a7b1a56b632;hp=d248d7200b71173a3d43c941ff60f094bb773f34;hpb=f2f8875638593bd5365cfd6a5ba7c9578e52322f;p=pintos-anon

diff --git a/src/threads/interrupt.c b/src/threads/interrupt.c
index d248d72..c886cc9 100644
--- a/src/threads/interrupt.c
+++ b/src/threads/interrupt.c
@@ -3,6 +3,7 @@
 #include <inttypes.h>
 #include <stdint.h>
 #include <stdio.h>
+#include "threads/flags.h"
 #include "threads/intr-stubs.h"
 #include "threads/io.h"
 #include "threads/mmu.h"
@@ -50,7 +51,7 @@ intr_get_level (void)
 {
   uint32_t flags;
   
-  asm ("pushfl; popl %0" : "=g" (flags));
+  asm volatile ("pushfl; popl %0" : "=g" (flags));
 
   return flags & FLAG_IF ? INTR_ON : INTR_OFF;
 }
@@ -68,6 +69,7 @@ enum intr_level
 intr_enable (void) 
 {
   enum intr_level old_level = intr_get_level ();
+  ASSERT (!intr_context ());
   asm volatile ("sti");
   return old_level;
 }
@@ -93,7 +95,7 @@ intr_init (void)
 
   /* Initialize IDT. */
   for (i = 0; i < INTR_CNT; i++)
-    idt[i] = make_trap_gate (intr_stubs[i], 0);
+    idt[i] = make_intr_gate (intr_stubs[i], 0);
 
   /* Load IDT register. */
   idtr_operand = make_idtr_operand (sizeof idt - 1, idt);
@@ -116,6 +118,7 @@ intr_init (void)
   intr_names[11] = "#NP Segment Not Present";
   intr_names[12] = "#SS Stack Fault Exception";
   intr_names[13] = "#GP General Protection Exception";
+  intr_names[14] = "#PF Page-Fault Exception";
   intr_names[16] = "#MF x87 FPU Floating-Point Error";
   intr_names[17] = "#AC Alignment Check Exception";
   intr_names[18] = "#MC Machine-Check Exception";
@@ -303,6 +306,10 @@ intr_handler (struct intr_frame *frame)
   bool external;
   intr_handler_func *handler;
 
+  /* External interrupts are special.
+     We only handle one at a time (so interrupts must be off)
+     and they need to be acknowledged on the PIC (see below).
+     An external interrupt handler cannot sleep. */
   external = frame->vec_no >= 0x20 && frame->vec_no < 0x30;
   if (external) 
     {