From fd3f51eecaecc12806a573c38263df1de43ee8c2 Mon Sep 17 00:00:00 2001
From: hachem <im@hachem.wtf>
Date: Fri, 25 Sep 2026 18:08:17 +0200
Subject: feat: pit timer

---
 boot/timer.zig | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 boot/timer.zig

(limited to 'boot/timer.zig')

diff --git a/boot/timer.zig b/boot/timer.zig
new file mode 100644
index 0000000..4569d6a
--- /dev/null
+++ b/boot/timer.zig
@@ -0,0 +1,17 @@
+// PIT channel 0 tick counter
+// configuring the PIT itself (outb to 0x43/0x40) is done in revo (kernel
+// `pit_init`), since it's just port writes the VM can drive
+
+var ticks: u64 = 0;
+
+// called from the IRQ0 handler
+pub fn onIrq() void {
+    const t: *volatile u64 = &ticks;
+    t.* +%= 1;
+}
+
+// called from the event loop
+pub fn now() u64 {
+    const t: *volatile u64 = &ticks;
+    return t.*;
+}
-- 
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