Move proc_man exit call into kernel

src/interrupts.rs

@@ -102,7 +102,7 @@ extern "x86-interrupt" fn page_fault_handler(
     } else {
         println!("page faulted {error_code:#?} at {:#x}\n{stack_frame:#?}", faulting_addr);
     }
-    TASKING.exit();
+    TASKING.exit(254);
 }
 
 #[expect(clippy::needless_pass_by_value, reason = "Signature dictated by external crate")]
@@ -118,7 +118,7 @@ fn exc_handler(_stack_frame: InterruptStackFrame, _index: u8, _error_code: Optio
         print!("Kernel init ");
     }
     println!("had exception, exiting");
-    TASKING.exit();
+    TASKING.exit(254);
 }
 
 pub struct EoiGuard(u8);
@@ -358,7 +358,7 @@ extern "C" fn syscall_handler() {
             };
             retval = rval;
         }
-        1 => TASKING.exit(),
+        1 => TASKING.exit(regs.rcx.wrapping_cast()),
         2 => {
             retval = if regs.rcx == 0 {
                 ACTIVE_SPACE

src/start.rs

@@ -13,5 +13,5 @@ entry_point!(start, config = &BOOTLOADER_CONFIG);
 fn start(bootinfo: &'static mut BootInfo) -> ! {
     BOOTINFO.set(bootinfo);
     main();
-    TASKING.exit();
+    TASKING.exit(0);
 }

src/tasking.rs

@@ -325,7 +325,33 @@ impl Tasking {
         *self.current_pid.read()
     }
 
-    pub fn exit(&self) -> ! {
+    pub fn exit(&self, code: u8) -> ! {
+        if let Some(current_pid) = *self.current_pid.read() {
+            if let Some(&proc_man_pid) = REGISTERD_PIDS.read().get(&3) {
+                let mut len: usize;
+                let rounded_size = 32usize.next_multiple_of(4096);
+                let mut buffer = Vec::with_capacity_in(rounded_size, &*ACTIVE_SPACE);
+                buffer.resize(rounded_size, 0);
+                let mut buffer = buffer.into_boxed_slice();
+                buffer[0..8].copy_from_slice(&u64::MAX.to_le_bytes());
+                buffer[8..10].copy_from_slice(&0u16.to_le_bytes());
+                buffer[10] = 0;
+                buffer[11..19].copy_from_slice(&0u64.to_le_bytes());
+                buffer[19..21].copy_from_slice(&8u16.to_le_bytes());
+                buffer[21..23].copy_from_slice(&4u16.to_le_bytes());
+                len = 23;
+                len += unsigned_varint::encode::u64(
+                    u64(current_pid),
+                    (&mut buffer[len..len + 10]).try_into().unwrap(),
+                )
+                .len();
+                buffer[len] = code;
+                len += 1;
+                send_ipc_to(usize(proc_man_pid), buffer, len);
+            } else {
+                println!("[TASKING] No process manager when PID {} exited with code {code}", current_pid);
+            }
+        }
         loop {
             let next_process_pid = self.ready_to_run.lock().pop_front();
             if let Some(next_process_pid) = next_process_pid {