X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?p=pintos-anon;a=blobdiff_plain;f=src%2Fdevices%2Fvga.c;h=f421b617bd3706858d2536eb21866531b1fd9b85;hp=bc2d6b72bd561321b16f2c8a877c397c4d7a2a26;hb=f1f2dc8de9e336d83383692d4478bb14a3dafc11;hpb=f2f8875638593bd5365cfd6a5ba7c9578e52322f

diff --git a/src/devices/vga.c b/src/devices/vga.c
index bc2d6b7..f421b61 100644
--- a/src/devices/vga.c
+++ b/src/devices/vga.c
@@ -3,8 +3,10 @@
 #include <stdint.h>
 #include <stddef.h>
 #include <string.h>
+#include "devices/speaker.h"
 #include "threads/io.h"
-#include "threads/mmu.h"
+#include "threads/interrupt.h"
+#include "threads/vaddr.h"
 
 /* VGA text screen support.  See [FREEVGA] for more information. */
 
@@ -28,20 +30,33 @@ static void clear_row (size_t y);
 static void cls (void);
 static void newline (void);
 static void move_cursor (void);
+static void find_cursor (size_t *x, size_t *y);
 
-/* Initializes the VGA text display and clears the screen. */
-void
-vga_init (void)
+/* Initializes the VGA text display. */
+static void
+init (void)
 {
-  fb = ptov (0xb8000);
-  cls ();
+  /* Already initialized? */
+  static bool inited;
+  if (!inited)
+    {
+      fb = ptov (0xb8000);
+      find_cursor (&cx, &cy);
+      inited = true; 
+    }
 }
 
 /* Writes C to the VGA text display, interpreting control
-   characters in the conventional ways. */
+   characters in the conventional ways.  */
 void
 vga_putc (int c)
 {
+  /* Disable interrupts to lock out interrupt handlers
+     that might write to the console. */
+  enum intr_level old_level = intr_disable ();
+
+  init ();
+  
   switch (c) 
     {
     case '\n':
@@ -66,6 +81,12 @@ vga_putc (int c)
       if (cx >= COL_CNT)
         newline ();
       break;
+
+    case '\a':
+      intr_set_level (old_level);
+      speaker_beep ();
+      intr_disable ();
+      break;
       
     default:
       fb[cy][cx][0] = c;
@@ -77,6 +98,8 @@ vga_putc (int c)
 
   /* Update cursor position. */
   move_cursor ();
+
+  intr_set_level (old_level);
 }
 
 /* Clears the screen and moves the cursor to the upper left. */
@@ -131,3 +154,19 @@ move_cursor (void)
   outw (0x3d4, 0x0f | (cp << 8));
 }
 
+/* Reads the current hardware cursor position into (*X,*Y). */
+static void
+find_cursor (size_t *x, size_t *y) 
+{
+  /* See [FREEVGA] under "Manipulating the Text-mode Cursor". */
+  uint16_t cp;
+
+  outb (0x3d4, 0x0e);
+  cp = inb (0x3d5) << 8;
+
+  outb (0x3d4, 0x0f);
+  cp |= inb (0x3d5);
+
+  *x = cp % COL_CNT;
+  *y = cp / COL_CNT;
+}