From 8c5424090eb6bb5a1d391e81f4fe728fa4102c41 Mon Sep 17 00:00:00 2001
From: h2-addad <hamza2.addad@live.uwe.ac.uk>
Date: Sun, 16 Jul 2023 00:38:16 +0000
Subject: [PATCH] Update
---
src/devices/speaker.c | 68 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)
create mode 100644 src/devices/speaker.c
diff --git a/src/devices/speaker.c b/src/devices/speaker.c
new file mode 100644
index 0000000..5052005
--- /dev/null
+++ b/src/devices/speaker.c
@@ -0,0 +1,68 @@
+#include "devices/speaker.h"
+#include "devices/pit.h"
+#include "threads/io.h"
+#include "threads/interrupt.h"
+#include "devices/timer.h"
+
+/* Speaker port enable I/O register. */
+#define SPEAKER_PORT_GATE 0x61
+
+/* Speaker port enable bits. */
+#define SPEAKER_GATE_ENABLE 0x03
+
+/* Sets the PC speaker to emit a tone at the given FREQUENCY, in
+ Hz. */
+void
+speaker_on (int frequency)
+{
+ if (frequency >= 20 && frequency <= 20000)
+ {
+ /* Set the timer channel that's connected to the speaker to
+ output a square wave at the given FREQUENCY, then
+ connect the timer channel output to the speaker. */
+ enum intr_level old_level = intr_disable ();
+ pit_configure_channel (2, 3, frequency);
+ outb (SPEAKER_PORT_GATE, inb (SPEAKER_PORT_GATE) | SPEAKER_GATE_ENABLE);
+ intr_set_level (old_level);
+ }
+ else
+ {
+ /* FREQUENCY is outside the range of normal human hearing.
+ Just turn off the speaker. */
+ speaker_off ();
+ }
+}
+
+/* Turn off the PC speaker, by disconnecting the timer channel's
+ output from the speaker. */
+void
+speaker_off (void)
+{
+ enum intr_level old_level = intr_disable ();
+ outb (SPEAKER_PORT_GATE, inb (SPEAKER_PORT_GATE) & ~SPEAKER_GATE_ENABLE);
+ intr_set_level (old_level);
+}
+
+/* Briefly beep the PC speaker. */
+void
+speaker_beep (void)
+{
+ /* Only attempt to beep the speaker if interrupts are enabled,
+ because we don't want to freeze the machine during the beep.
+ We could add a hook to the timer interrupt to avoid that
+ problem, but then we'd risk failing to ever stop the beep if
+ Pintos crashes for some unrelated reason. There's nothing
+ more annoying than a machine whose beeping you can't stop
+ without a power cycle.
+
+ We can't just enable interrupts while we sleep. For one
+ thing, we get called (indirectly) from printf, which should
+ always work, even during boot before we're ready to enable
+ interrupts. */
+ if (intr_get_level () == INTR_ON)
+ {
+ speaker_on (440);
+ timer_msleep (250);
+ speaker_off ();
+ }
+}
--
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