initial commit of lk (little kernel) project
diff --git a/platform/armemu/timer.c b/platform/armemu/timer.c
new file mode 100644
index 0000000..770905b
--- /dev/null
+++ b/platform/armemu/timer.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <sys/types.h>
+#include <err.h>
+#include <kernel/thread.h>
+#include <platform.h>
+#include <platform/interrupts.h>
+#include <platform/timer.h>
+#include <platform/armemu.h>
+#include "platform_p.h"
+
+static platform_timer_callback t_callback;
+
+status_t platform_set_periodic_timer(platform_timer_callback callback, void *arg, time_t interval)
+{
+	enter_critical_section();
+
+	t_callback = callback;
+
+	*REG(PIT_CLEAR) = 1;
+	*REG(PIT_INTERVAL) = interval;
+	*REG(PIT_START_PERIODIC) = 1;
+
+	unmask_interrupt(INT_PIT, NULL);
+
+	exit_critical_section();
+
+	return NO_ERROR;
+}
+
+time_t current_time(void)
+{
+	time_t time;
+	*REG(SYSINFO_TIME_LATCH) = 1;
+	time = *REG(SYSINFO_TIME_SECS) * 1000;
+	time += *REG(SYSINFO_TIME_USECS) / 1000;
+			
+	return time;
+}
+
+static enum handler_return platform_tick(void *arg)
+{
+	*REG(PIT_CLEAR_INT) = 1;
+	if (t_callback) {
+		return t_callback(arg, current_time());
+	} else {
+		return INT_NO_RESCHEDULE;
+	}
+}
+
+void platform_init_timer(void)
+{
+	register_int_handler(INT_PIT, &platform_tick, NULL);
+}
+