1 files changed, 45 insertions, 0 deletions
diff --git a/mubios/drivers/pit.c b/mubios/drivers/pit.c
new file mode 100644
index 0000000..4213940
--- /dev/null
+++ b/mubios/drivers/pit.c
@@ -0,0 +1,45 @@
+/*
+ RCC-Project
+
+ Copyright (C) 2026 Richard Qin
+
+ This file is part of RCC-Project.
+
+ RCC-Project is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at your option) any
+ later version.
+
+ RCC-Project is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ RCC-Project; see the file COPYING.  If not see
+ <http://www.gnu.org/licenses/>.
+ */
+
+#include "bios.h"
+#include "io.h"
+
+#define PIT_COUNTER0 0x0040u
+#define PIT_COMMAND  0x0043u
+
+#define PIT_SELECT_CHANNEL0 0x00u
+#define PIT_ACCESS_WORD     0x30u
+#define PIT_MODE_2          0x04u
+#define PIT_BINARY 0x00u
+
+#define PIT_COMMAND_CHANNEL0_MODE2                                            \
+  (PIT_SELECT_CHANNEL0 | PIT_ACCESS_WORD | PIT_MODE_2 | PIT_BINARY)
+
+void pit_init(void)
+{
+  io_out8 (PIT_COMMAND, PIT_COMMAND_CHANNEL0_MODE2);
+
+  /*
+   * A divisor of zero represents 65536.
+   */
+  io_out8 (PIT_COUNTER0, 0x00u);
+  io_out8 (PIT_COUNTER0, 0x00u);  
+}