feat: kernel/syscall: refactor

kernel/src/syscall.rs

@@ -2,17 +2,22 @@ use crate::{objects::*, plat::trap::TrapContextOps};
 use log::trace;
 use uapi::{error::*, syscall::*};
 
+macro_rules! assert_length {
+    ($info:expr, $len:expr) => {
+        if $info.length() != $len {
+            return Err(SysError::InvalidArgument);
+        }
+    };
+}
+
 pub fn handle_syscall(tcb: &mut TcbObject) -> SysResult {
-    let info = MessageInfo::try_from(tcb.trapframe.get_reg(0))?;
+    let info = MessageInfo::try_from(tcb.trapframe.get_reg(REG_MESSAGE_INFO))?;
 
     // Invalid, Debug*, Yield will bypass the capability check
     match info.label() {
         Syscall::Invalid => return Ok(()),
         Syscall::DebugPutChar => {
-            if info.length() != 3 {
-                return Err(SysError::InvalidArgument);
-            }
-
+            assert_length!(info, 3);
             let c = tcb.trapframe.get_reg(2) as u8 as char;
             crate::print!("{}", c);
             return Ok(());
@@ -25,13 +30,16 @@ pub fn handle_syscall(tcb: &mut TcbObject) -> SysResult {
     };
 
     let cspace = CNodeCap::try_from(tcb.cspace())?;
-    let cap_ptr = tcb.trapframe.get_reg(1);
+    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!("handle_syscall: info={:?} cap={:?}", info, cap);
 
     match info.label() {
-        Syscall::Send => Ok(()),
+        Syscall::InvokeNtfn => {
+            assert_length!(info, 2);
+            unimplemented!("[Syscall] InvokeNtfn: {:?}", info.label());
+        },
         _ => unimplemented!("handle_syscall: {:?}, {:?}", info.label(), cap),
     }
 }

uapi/src/syscall.rs

@@ -8,11 +8,11 @@ pub enum Syscall {
     Invalid      = 0,
     DebugPutChar = 1,
     Yield        = 2,
-    Identify     = 3,
-    Send         = 4,
-    Recv         = 5,
-    Call         = 6,
-    Reply        = 7,
+    InvokeNtfn   = 3,
+    // Send         = 4,
+    // Recv         = 5,
+    // Call         = 6,
+    // Reply        = 7,
 }
 
 /* Syscall convention:
@@ -26,6 +26,9 @@ pub enum Syscall {
  * > TODO: figure out how vanilla seL4 handle reply
  */
 
+pub const REG_MESSAGE_INFO: usize = 0;
+pub const REG_CAP_PTR: usize = 1;
+
 /* MessageInfo layout:
  * > | label   | bits   | length |
  * > | [63:13] | [12:7] | [6:0]  |