From 35fd771c84247bbeb04f5f945cb89735c25d0256 Mon Sep 17 00:00:00 2001
From: Timo Kreuzer <timo.kreuzer@reactos.org>
Date: Fri, 18 Apr 2025 11:57:45 +0300
Subject: [PATCH] [HALX86/APIC] Read APIC Id from APIC instead of using initial
 Id

This is needed on some hardware systems, where the BIOS has modified the actual APIC IDs.
The timer interrupt already did this, but in a broken way.
---
 hal/halx86/apic/apic.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/hal/halx86/apic/apic.c b/hal/halx86/apic/apic.c
index 96a0f8831cb..0ec72d5d949 100644
--- a/hal/halx86/apic/apic.c
+++ b/hal/halx86/apic/apic.c
@@ -385,7 +385,7 @@ HalpAllocateSystemInterrupt(
     ReDirReg.TriggerMode = APIC_TGM_Edge;
     ReDirReg.Mask = 1;
     ReDirReg.Reserved = 0;
-    ReDirReg.Destination = 0;
+    ReDirReg.Destination = ApicRead(APIC_ID) >> 24;
 
     /* Initialize entry */
     ApicWriteIORedirectionEntry(Irq, ReDirReg);
@@ -484,7 +484,7 @@ ApicInitializeIOApic(VOID)
     ReDirReg.TriggerMode = APIC_TGM_Edge;
     ReDirReg.Mask = 1;
     ReDirReg.Reserved = 0;
-    ReDirReg.Destination = 0;
+    ReDirReg.Destination = ApicRead(APIC_ID) >> 24;
 
     /* Loop all table entries */
     for (Index = 0; Index < APIC_MAX_IRQ; Index++)
@@ -505,7 +505,7 @@ ApicInitializeIOApic(VOID)
     ReDirReg.DestinationMode = APIC_DM_Physical;
     ReDirReg.TriggerMode = APIC_TGM_Level;
     ReDirReg.Mask = 1;
-    ReDirReg.Destination = ApicRead(APIC_ID);
+    ReDirReg.Destination = ApicRead(APIC_ID) >> 24;
     ApicWriteIORedirectionEntry(APIC_CLOCK_INDEX, ReDirReg);
 }
 
@@ -704,7 +704,7 @@ HalEnableSystemInterrupt(
     ReDirReg.Vector = Vector;
     ReDirReg.MessageType = APIC_MT_Fixed;
     ReDirReg.DestinationMode = APIC_DM_Physical;
-    ReDirReg.Destination = KeGetCurrentPrcb()->InitialApicId;
+    ReDirReg.Destination = ApicRead(APIC_ID) >> 24;
     ReDirReg.TriggerMode = (InterruptMode == LevelSensitive) ?
         APIC_TGM_Level : APIC_TGM_Edge;
     ReDirReg.Mask = FALSE;