i think it works

code/kernel/ke_idt.h

@@ -0,0 +1,34 @@
+#pragma once
+// ke_idt.h - IDT, GDT, and TSS setup
+#include <stdint.h>
+
+// 64-bit TSS - minimal; we only care about RSP0.
+#pragma pack(push, 1)
+typedef struct TSS64 {
+    uint32_t Reserved0;
+    uint64_t RSP0;           // loaded into RSP on ring-0 entry
+    uint64_t RSP1;
+    uint64_t RSP2;
+    uint64_t Reserved1;
+    uint64_t IST[7];
+    uint64_t Reserved2;
+    uint16_t Reserved3;
+    uint16_t IoMapBase;
+} TSS64;
+#pragma pack(pop)
+
+extern TSS64* gTss;
+
+void KeInitializeGdt(void);
+void KeInitializeIdt(void);
+
+// Called from hal_timer.c after HPET/APIC timer fires.
+void KeTimerInterrupt(void);
+
+// Syscall entry - implemented in ke_syscall.asm.
+extern void KeSyscallEntry(void);
+
+// Fault stubs installed by KeInitializeIdt.
+extern void KeFaultDE(void);   // #DE divide error
+extern void KeFaultGP(void);   // #GP general protection
+extern void KeFaultPF(void);   // #PF page fault