feat: kernel: separate syscall from tcb

kernel/src/main.rs

@@ -29,6 +29,7 @@ mod objects;
 mod plat;
 mod root;
 mod scheduler;
+mod syscall;
 mod vspace;
 
 // test infrastructure

kernel/src/objects/tcb.rs

@@ -1,8 +1,9 @@
 use crate::arch::{layout::mmap_phys_to_virt, trap::TrapContext, vspace::*};
+use crate::syscall::handle_syscall;
 use crate::{objects::*, plat::trap::TrapContextOps, vspace::*};
 use core::fmt::Debug;
 use core::sync::atomic::{AtomicUsize, Ordering};
-use uapi::{cap::ObjectType, error::SysResult, fault::*, syscall::*};
+use uapi::{cap::ObjectType, fault::*};
 use utils::{
     addr::*,
     linked_list::{Link, LinkHelper},
@@ -59,6 +60,10 @@ impl TcbObject {
         }
     }
 
+    pub fn cspace(&self) -> &CapEntry {
+        &self.cspace
+    }
+
     pub fn set_cspace(&mut self, cspace: CapEntry) {
         CNodeCap::try_from(&cspace).expect("set_cspace: invalid cap");
         self.cspace = cspace;
@@ -119,19 +124,8 @@ impl TcbObject {
     }
 
     pub fn handle_syscall(&mut self) {
-        let handle_syscall_inner = || -> SysResult {
-            let info = MessageInfo::try_from(self.trapframe.get_reg(0))?;
-
-            let cspace = CNodeCap::try_from(&self.cspace)?;
-            let cap_ptr = self.trapframe.get_reg(1);
-            let cap = cspace.resolve_address_bits(cap_ptr, usize::BITS as usize);
-
-            debug!("handle_syscall: info={:?}, cap={:?}", info, cap);
-
-            todo!("handle_syscall");
-        };
-
-        handle_syscall_inner().unwrap();
+        // TODO: don't panic here, return error to user instead
+        handle_syscall(self).unwrap();
     }
 }
 

kernel/src/syscall.rs

@@ -0,0 +1,29 @@
+use crate::{objects::*, plat::trap::TrapContextOps};
+use log::trace;
+use uapi::{error::*, syscall::*};
+
+pub fn handle_syscall(tcb: &mut TcbObject) -> SysResult {
+    let info = MessageInfo::try_from(tcb.trapframe.get_reg(0))?;
+    let cspace = CNodeCap::try_from(tcb.cspace())?;
+
+    let cap_ptr = tcb.trapframe.get_reg(1);
+    let cap = cspace
+        .resolve_address_bits(cap_ptr, usize::BITS as usize)
+        .map_err(|e| SysError::from(e))?;
+
+    trace!("handle_syscall: info={:?} cap={:?}", info, cap);
+
+    match info.label() {
+        Syscall::DebugPutChar => {
+            if info.length() != 3 {
+                return Err(SysError::InvalidArgument);
+            }
+
+            let c = tcb.trapframe.get_reg(2) as u8 as char;
+            crate::print!("{}", c);
+
+            return Ok(());
+        },
+        _ => unimplemented!("handle_syscall: {:?}, {:?}", info.label(), cap),
+    }
+}