From 22c42d69367e9ab98622e204801223b0c8de5b43 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Mon, 17 Nov 2025 16:48:35 -0500
Subject: kern/amd64: lapic: Add lapic_read_id() function

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 sys/arch/amd64/cpu/lapic.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

(limited to 'sys/arch')

diff --git a/sys/arch/amd64/cpu/lapic.c b/sys/arch/amd64/cpu/lapic.c
index 7f1c9f2..acf2573 100644
--- a/sys/arch/amd64/cpu/lapic.c
+++ b/sys/arch/amd64/cpu/lapic.c
@@ -337,6 +337,18 @@ lapic_enable(struct mcb *mcb)
     lapic_write(mcb, LAPIC_REG_SVR, svr | 0xFF);
 }
 
+uint32_t
+lapic_read_id(struct mcb *mcb)
+{
+    uint32_t id;
+
+    if (!mcb->has_x2apic) {
+        return (lapic_read(mcb, LAPIC_REG_ID) >> 24) & 0xF;
+    } else {
+        return lapic_read(mcb, LAPIC_REG_ID);
+    }
+}
+
 void
 lapic_init(void)
 {
-- 
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