kernel/src/objects/cap.rs

@@ -62,6 +62,7 @@ impl Debug for CapEntry {
             ObjectType::Table => write!(f, "{:?}", TableCap::try_from(self)),
             ObjectType::TCB => write!(f, "{:?}", TcbCap::try_from(self)),
             ObjectType::Untyped => write!(f, "{:?}", UntypedCap::try_from(self)),
+            _ => write!(f, "UnknownCap"),
         }
     }
 }

kernel/src/objects/endpoint.rs

@@ -1,34 +1,22 @@
-use crate::objects::*;
-use crate::plat::{
-    irq::{IRQ_MANAGER, IRQ_NUM},
-    trap::TrapContextOps,
-};
-use core::sync::atomic::AtomicPtr;
+use crate::{objects::*, plat::trap::TrapContextOps};
 use core::{cmp::min, fmt::Debug};
 use tcb::{ThreadState, EP_QUEUE_LINK_ID};
-use uapi::{cap::ObjectType, syscall::*};
-use utils::container_of_mut;
-use utils::then::Then;
+use uapi::{cap::ObjectType, fault::Fault, syscall::*};
 use utils::{addr::*, array::*, linked_list::Link};
 
 #[derive(Debug, Copy, Clone, PartialEq)]
 pub enum EndpointState {
     Idle,
-    Send,
-    Recv,
-    Signal,
+    Sending,
+    Receiving,
 }
 
 #[repr(C)]
 pub struct EndpointObject {
-    pub queue:   Link<TcbObject, EP_QUEUE_LINK_ID>,
-    pub signals: usize,
-    pub pending: usize,
+    pub queue: Link<TcbObject, EP_QUEUE_LINK_ID>,
+    pub state: EndpointState,
 }
 
-const_assert!(usize::BITS as usize >= IRQ_NUM);
-const_assert!(core::mem::size_of::<EndpointObject>() <= ObjectType::Endpoint.size(0));
-
 impl KernelObject for EndpointObject {
     const OBJ_TYPE: ObjectType = ObjectType::Endpoint;
 }
@@ -51,154 +39,95 @@ pub type EndpointCap<'a> = Cap<'a, EndpointObject>;
 
 impl<'a> EndpointCap<'a> {
     pub fn mint(ptr: PhysAddr, badge: usize) -> RawCap {
-        let cap = RawCap::new(badge, 0, ptr, ObjectType::Endpoint);
-
-        {
-            let cte = CapEntry::new(cap);
-            let mut ep = EndpointCap::try_from(&cte).unwrap();
-            let obj = ep.as_object_mut();
-
-            unsafe {
-                let head = Some(AtomicPtr::new(container_of_mut!(&obj.queue, TcbObject, ep_queue)));
-                obj.queue.set_next(&head);
-                obj.queue.set_prev(&head);
-            }
-        }
-
-        cap
+        RawCap::new(badge, 0, ptr, ObjectType::Endpoint)
     }
 
-    pub fn signals(&self) -> Option<usize> {
-        let signals = self.as_object().signals;
-        (signals != 0).then_some(signals)
+    pub fn can_send(&self) -> bool {
+        self.cap().get().args[0] & 0x2 != 0
     }
 
-    fn set_signal(&mut self, signal: usize) {
-        self.as_object_mut().signals |= 1 << signal;
+    pub fn can_recv(&self) -> bool {
+        self.cap().get().args[0] & 0x1 != 0
     }
 
     pub fn badge(&self) -> usize {
-        self.cap().get().args[0]
-    }
-
-    pub fn pendings(&self) -> usize {
-        self.as_object().pending
-    }
-
-    fn set_pendings(&mut self, pendings: usize) {
-        self.as_object_mut().pending = pendings & self.signals().unwrap_or(0);
+        self.cap().get().args[1]
     }
 
     pub fn state(&self) -> EndpointState {
-        let obj = self.as_object();
-
-        if obj.pending > 0 {
-            return EndpointState::Signal;
-        } else if obj.queue.is_empty() {
-            return EndpointState::Idle;
-        }
-
-        match obj.queue.next().unwrap().state() {
-            ThreadState::Sending => EndpointState::Send,
-            ThreadState::Receiving => EndpointState::Recv,
-            _ => EndpointState::Idle,
-        }
+        self.as_object().state
     }
 
-    pub fn do_set_irq(&mut self, tcb: &TcbObject) -> SysResult {
-        let irq = tcb.trapframe.get_reg(REG_ARG_0);
-        IRQ_MANAGER.lock().enable(irq, self.cte.clone());
-        self.set_signal(irq);
-        Ok(())
+    pub fn set_state(&mut self, state: EndpointState) {
+        self.as_object_mut().state = state;
     }
 
-    pub fn do_ack_irq(&mut self, tcb: &TcbObject) -> SysResult {
-        let irq = tcb.trapframe.get_reg(REG_ARG_0);
-        (self.signals().unwrap_or(0) & (1 << irq) != 0).else_err((), SysError::InvalidArgument)?;
-        IRQ_MANAGER.lock().complete(irq);
-        Ok(())
-    }
-
-    pub fn do_send(&mut self, send: &mut TcbObject) -> SysResult {
+    pub fn do_send(&mut self, send: &mut TcbObject) -> SysResult<()> {
         match self.state() {
-            EndpointState::Recv => {
-                debug_assert!(
-                    !self.as_object().queue.is_empty(),
-                    "[Endpoint] do_send: Receive endpoint queue must not be empty"
-                );
+            EndpointState::Idle | EndpointState::Sending => {
+                send.set_state(ThreadState::Sending);
+                send.set_badge(self.badge());
 
-                let badge = self.badge();
+                self.set_state(EndpointState::Sending);
+                self.as_object_mut().queue.append(send);
+            },
+            EndpointState::Receiving => {
+                assert!(!self.as_object().queue.is_empty(), "Receive endpoint queue must not be empty");
 
-                let recv = self.as_object_mut().queue.next_mut().unwrap();
-                recv.ep_queue.detach();
+                let recv = {
+                    let recv = self.as_object_mut().queue.next_mut().unwrap();
+                    recv.ep_queue.detach();
 
-                do_ipc(send, send.get_message_info()?, recv, recv.get_message_info()?, badge)?;
+                    // SAFETY: `recv` is detached from the queue, no longer related to `self`
+                    unsafe { &mut *(recv as *mut TcbObject) }
+                };
+
+                if self.as_object().queue.is_empty() {
+                    self.set_state(EndpointState::Idle);
+                }
+
+                do_ipc_transfer(send, send.get_message_info()?, recv, recv.get_message_info()?, self.badge())?;
 
                 recv.set_state(ThreadState::Running);
                 recv.schedule_next();
             },
-            _ => {
-                // no thread wants to recv msg, block sender and append it to queue
-                send.set_state(ThreadState::Sending);
-                self.as_object_mut().queue.append(send);
-            },
         };
 
         Ok(())
     }
 
-    pub fn do_recv(&mut self, recv: &mut TcbObject) -> SysResult {
+    pub fn do_recv(&mut self, recv: &mut TcbObject) -> SysResult<()> {
         match self.state() {
-            EndpointState::Send => {
-                debug_assert!(
-                    !self.as_object().queue.is_empty(),
-                    "[Endpoint] do_recv: Send endpoint queue must not be empty"
-                );
+            EndpointState::Idle | EndpointState::Receiving => {
+                recv.set_state(ThreadState::Receiving);
 
-                let badge = self.badge();
+                self.set_state(EndpointState::Receiving);
+                self.as_object_mut().queue.append(recv);
+            },
+            EndpointState::Sending => {
+                assert!(!self.as_object().queue.is_empty(), "Send endpoint queue must not be empty");
 
-                let send = self.as_object_mut().queue.next_mut().unwrap();
-                send.ep_queue.detach();
+                let send = {
+                    let send = self.as_object_mut().queue.next_mut().unwrap();
+                    send.ep_queue.detach();
 
-                do_ipc(send, send.get_message_info()?, recv, recv.get_message_info()?, badge)?;
+                    // SAFETY: `send` is detached from the queue, no longer related to `self`
+                    unsafe { &mut *(send as *mut TcbObject) }
+                };
+
+                if self.as_object().queue.is_empty() {
+                    self.set_state(EndpointState::Idle);
+                }
+
+                do_ipc_transfer(send, send.get_message_info()?, recv, recv.get_message_info()?, self.badge())?;
 
                 send.set_state(ThreadState::Running);
                 send.schedule_next();
             },
-            EndpointState::Signal => {
-                do_signal_reply(recv, self.pendings())?;
-            },
-            _ => {
-                // no thread sent msg or no signal happens, block receiver and append it to queue
-                recv.set_state(ThreadState::Receiving);
-                self.as_object_mut().queue.append(recv);
-            },
         };
 
         Ok(())
     }
-
-    pub fn do_signal(&mut self, irq: usize) -> SysResult {
-        let signals = self.pendings() | (1 << irq);
-        let state = self.state();
-
-        self.set_pendings(signals);
-        let signals = self.pendings(); // set_signals will filter out invalid signals
-
-        if state == EndpointState::Recv && signals != 0 {
-            // do recv immediately
-            self.set_pendings(0);
-
-            let recv = self.as_object_mut().queue.next_mut().unwrap();
-            recv.ep_queue.detach();
-            recv.set_state(ThreadState::Running);
-            recv.schedule_next();
-
-            do_signal_reply(recv, signals)?;
-        }
-
-        Ok(())
-    }
 }
 
 impl Debug for EndpointCap<'_> {
@@ -206,19 +135,14 @@ impl Debug for EndpointCap<'_> {
         f.debug_struct("EndpointCap")
             .field("ptr", &self.cap().get().ptr)
             .field("badge", &self.badge())
-            .field("irqs", &self.signals())
-            .field("signals", &self.pendings())
+            .field("can_send", &self.can_send())
+            .field("can_recv", &self.can_recv())
             .field("state", &self.state())
             .finish()
     }
 }
 
-fn copy_message(
-    send: &mut TcbObject,
-    send_msg: MessageInfo,
-    recv: &mut TcbObject,
-    recv_msg: MessageInfo,
-) -> SysResult<usize> {
+fn copy_message(send: &mut TcbObject, send_msg: MessageInfo, recv: &mut TcbObject, recv_msg: MessageInfo) -> SysResult<()> {
     let send_len = send_msg.length() - if send_msg.transfer_cap() { 2 } else { 0 };
     let recv_len = recv_msg.length() - if recv_msg.transfer_cap() { 2 } else { 0 };
     let msg_len = min(send_len, recv_len);
@@ -239,7 +163,7 @@ fn copy_message(
         recv.trapframe.set_reg(i, send.trapframe.get_reg(i));
     }
 
-    Ok(msg_len)
+    Ok(())
 }
 
 fn ipc_get_args(tcb: &TcbObject, idx: usize) -> SysResult<usize> {
@@ -254,14 +178,9 @@ fn ipc_get_args(tcb: &TcbObject, idx: usize) -> SysResult<usize> {
     Ok(ret)
 }
 
-fn transfer_cap(
-    send: &mut TcbObject,
-    send_msg: MessageInfo,
-    recv: &mut TcbObject,
-    recv_msg: MessageInfo,
-) -> SysResult<bool> {
+fn transfer_cap(send: &mut TcbObject, send_msg: MessageInfo, recv: &mut TcbObject, recv_msg: MessageInfo) -> SysResult<()> {
     if !send_msg.transfer_cap() || !recv_msg.transfer_cap() {
-        return Ok(false);
+        return Ok(());
     }
 
     let send_cspace = send.cspace()?;
@@ -280,33 +199,24 @@ fn transfer_cap(
     dest.override_cap(send_cap.cap.get());
     send_cap.cap.replace(NullCap::mint());
 
-    Ok(true)
+    Ok(())
 }
 
-fn do_ipc(
+fn do_ipc_transfer(
     send: &mut TcbObject,
     send_msg: MessageInfo,
     recv: &mut TcbObject,
     recv_msg: MessageInfo,
-    badge: usize,
-) -> SysResult {
-    // do normal transfer
+    _badge: usize,
+) -> SysResult<()> {
+    if send.fault() == Fault::Null {
+        // do normal transfer
+        copy_message(send, send_msg, recv, recv_msg)?;
+        transfer_cap(send, send_msg, recv, recv_msg)?;
 
-    let length = copy_message(send, send_msg, recv, recv_msg)?;
-    let transfered = transfer_cap(send, send_msg, recv, recv_msg)?;
-
-    let reply = ReplyInfo::new(ReplyLabel::Message, length, true, transfered, SysError::Ok);
-    recv.trapframe.set_reg(REG_REPLY_INFO, reply.into());
-    recv.trapframe.set_reg(REG_BADGE, badge);
-
-    Ok(())
-}
-
-fn do_signal_reply(recv: &mut TcbObject, signals: usize) -> SysResult {
-    let reply = ReplyInfo::new(ReplyLabel::Signal, 2, false, false, SysError::Ok);
-
-    recv.trapframe.set_reg(REG_REPLY_INFO, reply.into());
-    recv.trapframe.set_reg(REG_BADGE, signals);
-
-    Ok(())
+        todo!("do_ipc_transfer: normal transfer: uapi/reply");
+    } else {
+        // do fault transfer
+        todo!("do_ipc_transfer: fault transfer");
+    }
 }

kernel/src/objects/tcb.rs

@@ -39,6 +39,7 @@ pub struct TcbObject {
     vspace: CapEntry,
 
     // endpoint
+    badge:  usize,
     buffer: CapEntry,
     fault:  Fault,
 
@@ -62,6 +63,7 @@ impl TcbObject {
             trapframe:   TrapContext::default(),
             cspace:      CapEntry::new(NullCap::mint()),
             vspace:      CapEntry::new(NullCap::mint()),
+            badge:       0,
             buffer:      CapEntry::new(NullCap::mint()),
             fault:       Fault::Null,
             state:       ThreadState::Inactive,
@@ -95,6 +97,14 @@ impl TcbObject {
         self.vspace = vspace;
     }
 
+    pub fn badge(&self) -> usize {
+        self.badge
+    }
+
+    pub fn set_badge(&mut self, badge: usize) {
+        self.badge = badge;
+    }
+
     pub fn buffer(&self) -> SysResult<FrameCap> {
         FrameCap::try_from(&self.buffer)
     }
@@ -188,6 +198,7 @@ impl Debug for TcbCap<'_> {
         f.debug_struct("TcbCap")
             .field("cspace", &obj.cspace)
             .field("vspace", &obj.vspace)
+            .field("badge", &obj.badge)
             .field("buffer", &obj.buffer)
             .field("fault", &obj.fault)
             .field("state", &obj.state)

kernel/src/objects/untyped.rs

@@ -117,7 +117,6 @@ impl UntypedCap<'_> {
                 ObjectType::TCB => TcbCap::mint(addr),
                 ObjectType::Table => TableCap::mint(addr),
                 ObjectType::Frame => FrameCap::mint(addr, user_obj_bits, MapAttr::empty(), self.is_device()),
-                ObjectType::Endpoint => EndpointCap::mint(addr, 0),
                 // TODO: other object types
                 _ => return Err(SysError::InvalidArgument),
             };

kernel/src/plat/irq.rs

@@ -1,10 +1,10 @@
 use super::utils::generate_driver;
 use crate::drivers::irq::IrqPlic;
 use crate::objects::*;
-use log::{error, trace, warn};
+use log::{error, warn};
 use spin::{lazy::Lazy, Mutex};
 
-pub const IRQ_NUM: usize = 32;
+const IRQ_NUM: usize = 32;
 
 #[derive(Debug, Copy, Clone, PartialEq)]
 pub enum IrqState {
@@ -50,6 +50,7 @@ pub fn set_irq_driver(driver: IrqDriver) {
 
 pub struct IrqManager {
     handler: [CapEntry; IRQ_NUM],
+    state:   [IrqState; IRQ_NUM],
 }
 
 pub static IRQ_MANAGER: Lazy<Mutex<IrqManager>> = Lazy::new(|| Mutex::new(IrqManager::new()));
@@ -58,31 +59,10 @@ impl IrqManager {
     pub fn new() -> Self {
         Self {
             handler: core::array::from_fn::<_, IRQ_NUM, _>(|_| CapEntry::new(NullCap::mint())),
+            state:   [IrqState::Inactive; IRQ_NUM],
         }
     }
 
-    pub fn enable(&mut self, irq: usize, cap: CapEntry) {
-        if irq >= IRQ_NUM {
-            error!("[IrqManager] Invalid IRQ number: {}", irq);
-            return;
-        }
-
-        if NullCap::try_from(&self.handler[irq]).is_ok() {
-            self.handler[irq] = cap;
-            IRQ_DRIVER.lock().complete(irq);
-            IRQ_DRIVER.lock().enable(irq);
-        }
-    }
-
-    pub fn complete(&mut self, irq: usize) {
-        if irq >= IRQ_NUM {
-            error!("[IrqManager] Invalid IRQ number: {}", irq);
-            return;
-        }
-
-        IRQ_DRIVER.lock().complete(irq);
-    }
-
     pub fn dispatch(&mut self) {
         let irq = IRQ_DRIVER.lock().claim();
         if irq.is_none() {
@@ -90,16 +70,30 @@ impl IrqManager {
             return;
         }
 
-        if let Some(irq) = irq
-            && irq < IRQ_NUM
-            && let Ok(mut cap) = EndpointCap::try_from(&self.handler[irq])
-        {
-            trace!("[IrqManager] Dispatching IRQ: {}", irq);
-            cap.do_signal(irq).unwrap();
-        } else {
-            warn!("[IrqManager] Received invalid IRQ: {:?}", irq);
-            IRQ_DRIVER.lock().disable(irq.unwrap());
-            IRQ_DRIVER.lock().complete(irq.unwrap());
+        let irq = irq.unwrap();
+        if irq >= IRQ_NUM {
+            error!("[IrqManager] Invalid IRQ number: {}", irq);
+            IRQ_DRIVER.lock().disable(irq);
+            IRQ_DRIVER.lock().complete(irq);
+            return;
         }
+
+        match self.state[irq] {
+            IrqState::Inactive => {
+                warn!("[IrqManager] Received disabled IRQ: {}", irq);
+                IRQ_DRIVER.lock().disable(irq);
+            },
+            IrqState::Signal => {
+                // TODO: send signal via endpoint
+                warn!("[IrqManager] Undelivered IRQ: {}", irq);
+                IRQ_DRIVER.lock().disable(irq);
+            },
+            IrqState::Ipi => {
+                todo!("Kernel: NO SMP support now");
+            },
+            IrqState::Reserved => error!("[IrqManager] Received unhandled reserved IRQ: {}", irq),
+        }
+
+        IRQ_DRIVER.lock().complete(irq);
     }
 }

kernel/src/syscall.rs

@@ -3,16 +3,11 @@ use log::trace;
 use uapi::{error::*, syscall::*};
 
 macro_rules! assert_length {
-    ($info:ident, $len:expr) => {
+    ($info:expr, $len:expr) => {
         if $info.length() != $len {
             return Err(SysError::InvalidArgument);
         }
     };
-    ($info:ident >= $len:expr) => {
-        if $info.length() < $len {
-            return Err(SysError::InvalidArgument);
-        }
-    };
 }
 
 pub fn handle_syscall(tcb: &mut TcbObject) -> SysResult {
@@ -34,37 +29,17 @@ pub fn handle_syscall(tcb: &mut TcbObject) -> SysResult {
         _ => (),
     };
 
-    assert_length!(info >= 2);
-
-    // workaround ownership check
-    let tcb_cspace = unsafe { &mut *(tcb as *mut TcbObject) };
-    let cspace = tcb_cspace.cspace()?;
-
+    let cspace = tcb.cspace()?;
     let cap_ptr = tcb.trapframe.get_reg(REG_CAP_PTR);
     let cap = cspace.resolve_address_bits(cap_ptr, info.bits()).map_err(SysError::from)?;
 
-    trace!("[Syscall] info={:?} cap={:?}", info, cap);
+    trace!("handle_syscall: info={:?} cap={:?}", info, cap);
 
     match info.label() {
-        // Endpoint
-        Syscall::EpSend => {
-            let mut cap = EndpointCap::try_from(cap)?;
-            cap.do_send(tcb)
+        Syscall::InvokeNtfn => {
+            assert_length!(info, 2);
+            unimplemented!("[Syscall] InvokeNtfn: {:?}", info.label());
         },
-        Syscall::EpRecv => {
-            let mut cap = EndpointCap::try_from(cap)?;
-            cap.do_recv(tcb)
-        },
-        Syscall::IrqSet => {
-            assert_length!(info, 3);
-            let mut cap = EndpointCap::try_from(cap)?;
-            cap.do_set_irq(tcb)
-        },
-        Syscall::IrqAck => {
-            assert_length!(info, 3);
-            let mut cap = EndpointCap::try_from(cap)?;
-            cap.do_ack_irq(tcb)
-        },
-        _ => todo!("[Syscall] unhandled syscall: {:?}, {:?}", info.label(), cap),
+        _ => unimplemented!("handle_syscall: {:?}, {:?}", info.label(), cap),
     }
 }

lib/utils/src/linked_list.rs

@@ -66,6 +66,8 @@ impl<T: LinkHelper<ID>, const ID: usize> Link<T, ID> {
     }
 
     pub fn is_empty(&self) -> bool {
+        debug_assert!(!(self.prev.is_none() && self.next.is_some()));
+        debug_assert!(!(self.prev.is_some() && self.next.is_none()));
         self.prev.is_none() && self.next.is_none()
     }
 

uapi/src/cap.rs

@@ -1,12 +1,15 @@
 #[derive(Clone, Copy, Debug, Eq, PartialEq, FromPrimitive, ToPrimitive)]
 pub enum ObjectType {
-    Null     = 0,
-    CNode    = 1,
-    TCB      = 2,
-    Endpoint = 3,
-    Frame    = 4,
-    Table    = 5,
-    Untyped  = 6,
+    Null         = 0,
+    CNode        = 1,
+    TCB          = 2,
+    Endpoint     = 3,
+    Reply        = 4,
+    Notification = 5,
+    Frame        = 6,
+    Table        = 7,
+    Interrupt    = 8,
+    Untyped      = 9,
 }
 
 impl Default for ObjectType {
@@ -16,9 +19,8 @@ impl Default for ObjectType {
 }
 
 impl ObjectType {
-    const CNODE_BITS: usize = 5; // 32 bytes
+    const CNODE_BITS: usize = 6; // 48 bytes
     const TCB_BITS: usize = 10; // 672 bytes
-    const ENDPOINT_BITS: usize = 6; // 40 bytes
 
     pub const fn size(&self, user_obj_bits: usize) -> usize {
         1 << self.bits(user_obj_bits)
@@ -30,9 +32,12 @@ impl ObjectType {
             ObjectType::Null         => 0,
             ObjectType::CNode        => Self::CNODE_BITS + user_obj_bits,
             ObjectType::TCB          => Self::TCB_BITS,
-            ObjectType::Endpoint     => Self::ENDPOINT_BITS,
+            ObjectType::Endpoint     => 0, // TODO: fill it!
+            ObjectType::Reply        => 0, // TODO: fill it!
+            ObjectType::Notification => 0, // TODO: fill it!
             ObjectType::Frame        => user_obj_bits,
             ObjectType::Table        => user_obj_bits, // arch dependent page table size
+            ObjectType::Interrupt    => 0, // TODO: fill it!
             ObjectType::Untyped      => user_obj_bits,
         }
     }

uapi/src/error.rs

@@ -1,7 +1,6 @@
 #[derive(Clone, Copy, Debug, Eq, PartialEq, FromPrimitive, ToPrimitive)]
 pub enum SysError {
     Ok,
-    Invalid,
     InvalidArgument,
     CapTypeMismatch, // Cap, Untyped
     SlotNotEmpty,    // Untyped

uapi/src/syscall.rs

@@ -8,20 +8,11 @@ pub enum Syscall {
     Invalid      = 0,
     DebugPutChar = 1,
     Yield        = 2,
-
-    // endpoint
-    EpSend       = 3,
-    EpRecv       = 4,
-    IrqSet       = 5,
-    IrqAck       = 6,
-}
-
-#[derive(Clone, Copy, Debug, Eq, PartialEq, FromPrimitive, ToPrimitive)]
-pub enum ReplyLabel {
-    Invalid = 0,
-    Message = 1,
-    Signal  = 2,
-    Fault   = 3,
+    InvokeNtfn   = 3,
+    // Send         = 4,
+    // Recv         = 5,
+    // Call         = 6,
+    // Reply        = 7,
 }
 
 /* Syscall convention:
@@ -36,16 +27,9 @@ pub enum ReplyLabel {
  * > > if info.transfer_cap { Arguments[-2] = cap_ptr; Arguments[-1] = n_bits; }
  * >
  * > Reply:
- * > > +----------+-------------------------+--------------+
- * > > | [a0]     | REG_REPLY_INFO          | ReplyInfo    |
- * > > | [a1]     | REG_BADGE               | Badge        |
- * > > | [a2..a7] | REG_ARG_0..=REG_ARG_MAX | Replied Data |
- * > > | buffer   | REG_ARG_MAX+1..         | Replied Data |
- * > > +----------+-------------------------+--------------+
- * > > length = (a0..).length(), extra data are stored on ipc buffer
+ * > TODO: figure out how vanilla seL4 handle reply
  */
 
-// Call
 pub const REG_MESSAGE_INFO: usize = 0;
 pub const REG_CAP_PTR: usize = 1;
 pub const REG_ARG_0: usize = 2;
@@ -54,10 +38,6 @@ pub const REG_ARG_MAX: usize = 7;
 pub const LEN_ARG_OFFSET_CPTR: usize = 2;
 pub const LEN_ARG_OFFSET_BITS: usize = 1;
 
-// Reply
-pub const REG_REPLY_INFO: usize = 0;
-pub const REG_BADGE: usize = 1;
-
 /* MessageInfo layout:
  * > +---------+--------+--------+--------------+
  * > | label   | bits   | length | transfer_cap |
@@ -85,9 +65,9 @@ impl MessageInfo {
     const TRANSFER_CAP_OFFSET: usize = 0;
 
     pub fn new(label: Syscall, bits: usize, length: usize, transfer_cap: bool) -> Self {
-        let label = label.to_usize().unwrap();
+        let label = label.to_usize().unwrap_or(0);
         let bits = bits - 1; // stored as n_bits - 1
-        let transfer_cap = if transfer_cap { 1 } else { 0 };
+        let transfer_cap = transfer_cap as usize;
 
         assert!(label <= Self::LABEL_MASK);
         assert!(bits <= Self::BITS_MASK);
@@ -137,109 +117,6 @@ impl TryFrom<usize> for MessageInfo {
 
     fn try_from(value: usize) -> Result<Self, Self::Error> {
         let info = Self(value);
-        (info.label() != Syscall::Invalid).then_ok(info, SysError::Invalid)
-    }
-}
-
-impl Into<usize> for MessageInfo {
-    fn into(self) -> usize {
-        self.0
-    }
-}
-
-/* ReplyInfo layout:
- * > +---------+--------+--------+------------+-------+
- * > | label   | length | badged | transfered | error |
- * > | [16:14] | [13:7] | [6]    | [5]        | [4:0] |
- * > +---------+--------+--------+------------+-------+
- * > label:      reply label
- * > length:     args.len()
- * > badged:     if badged
- * > transfered: if cap is transfered
- * > error:      error code
- * >
- * > Fault / Signal: badged = false, REG_BADGE = fault detail/signal number
- */
-pub struct ReplyInfo(usize);
-
-impl ReplyInfo {
-    const LABEL_MASK: usize = MASK!(16 - 14 + 1);
-    const LABEL_OFFSET: usize = 14;
-
-    const LENGTH_MASK: usize = MASK!(13 - 7 + 1);
-    const LENGTH_OFFSET: usize = 7;
-
-    const BADGED_MASK: usize = MASK!(1);
-    const BADGED_OFFSET: usize = 6;
-
-    const TRANSFERED_MASK: usize = MASK!(1);
-    const TRANSFERED_OFFSET: usize = 5;
-
-    const ERROR_MASK: usize = MASK!(4 - 0 + 1);
-    const ERROR_OFFSET: usize = 0;
-
-    pub fn new(label: ReplyLabel, length: usize, badged: bool, transfered: bool, error: SysError) -> Self {
-        let label = label.to_usize().unwrap();
-        let badged = if badged { 1 } else { 0 };
-        let transfered = if transfered { 1 } else { 0 };
-        let error = error.to_usize().unwrap();
-
-        assert!(label <= Self::LABEL_MASK);
-        assert!(length <= Self::LENGTH_MASK);
-        assert!(error <= Self::ERROR_MASK);
-
-        let info = ((label & Self::LABEL_MASK) << Self::LABEL_OFFSET)
-            | ((length & Self::LENGTH_MASK) << Self::LENGTH_OFFSET)
-            | ((badged & Self::BADGED_MASK) << Self::BADGED_OFFSET)
-            | ((transfered & Self::TRANSFERED_MASK) << Self::TRANSFERED_OFFSET)
-            | ((error & Self::ERROR_MASK) << Self::ERROR_OFFSET);
-        Self(info)
-    }
-
-    pub fn label(&self) -> ReplyLabel {
-        ReplyLabel::from_usize((self.0 >> Self::LABEL_OFFSET) & Self::LABEL_MASK).unwrap_or(ReplyLabel::Invalid)
-    }
-
-    pub fn length(&self) -> usize {
-        (self.0 >> Self::LENGTH_OFFSET) & Self::LENGTH_MASK
-    }
-
-    pub fn badged(&self) -> bool {
-        (self.0 >> Self::BADGED_OFFSET) & Self::BADGED_MASK != 0
-    }
-
-    pub fn transfered(&self) -> bool {
-        (self.0 >> Self::TRANSFERED_OFFSET) & Self::TRANSFERED_MASK != 0
-    }
-
-    pub fn error(&self) -> SysError {
-        SysError::from_usize((self.0 >> Self::ERROR_OFFSET) & Self::ERROR_MASK).unwrap_or(SysError::Invalid)
-    }
-}
-
-impl Debug for ReplyInfo {
-    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-        f.debug_struct("ReplyInfo")
-            .field("label", &self.label())
-            .field("length", &self.length())
-            .field("badged", &self.badged())
-            .field("transfered", &self.transfered())
-            .field("error", &self.error())
-            .finish()
-    }
-}
-
-impl TryFrom<usize> for ReplyInfo {
-    type Error = SysError;
-
-    fn try_from(value: usize) -> Result<Self, Self::Error> {
-        let info = Self(value);
-        (info.label() != ReplyLabel::Invalid).then_ok(info, SysError::Invalid)
-    }
-}
-
-impl Into<usize> for ReplyInfo {
-    fn into(self) -> usize {
-        self.0
+        (info.label() != Syscall::Invalid).then_ok(info, SysError::InvalidArgument)
     }
 }