From 38310e4f234f2fd3cefd7d7529736249bdb9109a Mon Sep 17 00:00:00 2001
From: "Chloe M." <chloe@mensia.org>
Date: Fri, 26 Jun 2026 20:22:20 +0000
Subject: [PATCH] stos/amd64: cpu: Hardware enable Local APIC

Signed-off-by: Chloe M. <chloe@mensia.org>
---
 paw/stos/arch/amd64/cpu/lapic.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/paw/stos/arch/amd64/cpu/lapic.c b/paw/stos/arch/amd64/cpu/lapic.c
index dc52a22..3cc0bfc 100644
--- a/paw/stos/arch/amd64/cpu/lapic.c
+++ b/paw/stos/arch/amd64/cpu/lapic.c
@@ -7,6 +7,7 @@
  */
 
 #include <machine/lapic.h>
+#include <machine/lapicreg.h>
 #include <machine/msr.h>
 #include <machine/cpuid.h>
 #include <ex/trace.h>
@@ -39,6 +40,20 @@ LapicIsSupported(VOID)
     return ISSET(Edx, BIT(9)) != 0;
 }
 
+/*
+ * Enable the Local APIC unit
+ */
+static VOID
+LapicEnable(VOID)
+{
+    UQUAD ApicBase;
+
+    /* Hardware enable the Local APIC unit */
+    ApicBase = MdRdmsr(IA32_APIC_BASE_MSR);
+    ApicBase |= LAPIC_HW_ENABLE;
+    MdWrmsr(IA32_APIC_BASE_MSR, ApicBase);
+}
+
 VOID
 MdLapicInit(KPCR *Kpcr)
 {
@@ -49,4 +64,6 @@ MdLapicInit(KPCR *Kpcr)
     if (!LapicIsSupported()) {
         KeKnot(KNOT_MISSING_HARDWARE, "local apic not supported\n");
     }
+
+    LapicEnable();
 }