diff --git a/src/entry.rs b/src/entry.rs
index 724c355..adfa75a 100644
--- a/src/entry.rs
+++ b/src/entry.rs
@@ -1,14 +1,21 @@
-unsafe extern "C" fn _enter() -> ! {
+use crate::abort;
+
+unsafe extern "C" fn _enter() {
     let id = riscv::register::mhartid::read();
-    crate::entry::write_tp(&id);
+    write_tp(&id);
+    // TODO: set up stack for all harts
+    // TODO: set up CSRs for all harts
+    if id != 0 { abort(); }
+
+    // TODO: clear BSS
+    // TODO: do hardware inits and wake other harts
 }
 
 #[inline]
-unsafe fn write_tp(id: &usize) -> ! {
+unsafe fn write_tp(id: &usize) {
     use core::arch::asm;
     asm!(
         "csrw mhartid, {id}",
         id = in(reg) id,
-        options(noreturn)
     );
 }
\ No newline at end of file