From bdd20608fa9b914e8253ec3503c7c68497d7fd3e Mon Sep 17 00:00:00 2001
From: Nathan Singer <nathan.r.singer@gmx.com>
Date: Thu, 29 May 2025 10:23:06 -0400
Subject: [PATCH] small gdt fix

---
 kernel/kmain.c | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/kernel/kmain.c b/kernel/kmain.c
index 34911c4..76f9e77 100644
--- a/kernel/kmain.c
+++ b/kernel/kmain.c
@@ -5,19 +5,28 @@
 #include <kernel/serial.h>
 #include <kernel/x86/gdt.h>
 
-uint64_t gdt[5];
+#define GDT_SIZE 5
+
+uint64_t gdt[GDT_SIZE];
+
+
+void gdt_init(void)
+{ 
+	gdt[0] = create_descriptor(0, 0, 0); // null
+	gdt[1] = create_descriptor(0, 0x000FFFFF, (GDT_CODE_PL0)); // kernel code
+	gdt[2] = create_descriptor(0, 0x000FFFFF, (GDT_DATA_PL0)); // kernel data
+	gdt[3] = create_descriptor(0, 0x000FFFFF, (GDT_CODE_PL3)); // user code
+	gdt[4] = create_descriptor(0, 0x000FFFFF, (GDT_DATA_PL3)); // user data
+
+	setGdt((sizeof(uint64_t) * GDT_SIZE) - 1, &(gdt[0])); // limit, base
+	reloadSegments();
+}
+
+#undef GDT_SIZE
 
 void kmain(void)
 {
-	gdt[0] = create_descriptor(0, 0, 0); // null
-	gdt[1] = create_descriptor(0, 0x000FFFFF, (GDT_CODE_PL0));
-	gdt[2] = create_descriptor(0, 0x000FFFFF, (GDT_DATA_PL0));
-	gdt[3] = create_descriptor(0, 0x000FFFFF, (GDT_CODE_PL3));
-	gdt[4] = create_descriptor(0, 0x000FFFFF, (GDT_DATA_PL3));
-
-	setGdt((sizeof(uint64_t) * 5) - 1, &(gdt[0]));
-	reloadSegments();
-	
+	gdt_init();		
 
 	terminal_initialize();
 	serial_initialize();