1 files changed, 47 insertions, 0 deletions
diff --git a/kernel/boot/gdt/gdt.c b/kernel/boot/gdt/gdt.c
new file mode 100644
index 0000000..3728b32
--- /dev/null
+++ b/kernel/boot/gdt/gdt.c
@@ -0,0 +1,47 @@
+/*
+ * bubbl
+ * Copyright (C) 2024-2025  Raghuram Subramani <raghus2247@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <boot/gdt.h>
+
+static gdt_entry_t l_entries[] = {
+  /* NULL Descriptor */
+  GDT_ENTRY(0, 0, 0, 0),
+
+  /* Kernel Mode Code Segment */
+  GDT_ENTRY(0, 0xfffff, GDT_KERNEL_CODE_SEGMENT_ACCESS_FLAGS, GDT_FLAGS),
+
+  /* Kernel Mode Data Segment */
+  GDT_ENTRY(0, 0xfffff, GDT_KERNEL_DATA_SEGMENT_ACCESS_FLAGS, GDT_FLAGS),
+
+  /* User Mode Code Segment */
+  // GDT_ENTRY(0, 0xfffff, GDT_USER_CODE_SEGMENT_ACCESS_FLAGS, FLAGS),
+
+  /* User Mode Data Segment */
+  // GDT_ENTRY(0, 0xfffff, GDT_USER_DATA_SEGMENT_ACCESS_FLAGS, FLAGS)
+
+  /* TODO: TSS? */
+  /* TODO: LDT? */
+};
+
+static gdt_descriptor_t descriptor = { sizeof(l_entries) - 1, l_entries };
+
+void
+gdt_load(void)
+{
+  _GDT_flush(&descriptor);
+}