Code Transplanting: Blocking getchar

kernel/src/arch/riscv32/interrupt.rs

@@ -22,6 +22,8 @@ pub fn init() {
         stvec::write(__alltraps as usize, stvec::TrapMode::Direct);
         // Enable IPI
         sie::set_ssoft();
+        // Enable serial interrupt
+        sie::set_sext();
     }
     info!("interrupt: init end");
 }
@@ -72,6 +74,7 @@ pub extern fn rust_trap(tf: &mut TrapFrame) {
     use super::riscv::register::scause::{Trap, Interrupt as I, Exception as E};
     trace!("Interrupt: {:?}", tf.scause.cause());
     match tf.scause.cause() {
+        Trap::Interrupt(I::SupervisorExternal) => serial(),
         Trap::Interrupt(I::SupervisorTimer) => timer(),
         Trap::Exception(E::IllegalInstruction) => illegal_inst(tf),
         Trap::Exception(E::UserEnvCall) => syscall(tf),
@@ -83,6 +86,10 @@ pub extern fn rust_trap(tf: &mut TrapFrame) {
     trace!("Interrupt end");
 }
 
+fn serial() {
+    ::trap::serial(super::io::getchar());
+}
+
 fn ipi() {
     debug!("IPI");
     super::bbl::sbi::clear_ipi();

kernel/src/console.rs

@@ -1,11 +1,14 @@
 use core::ops::Deref;
 use alloc::string::String;
 use arch::io::getchar;
+use alloc::collections::VecDeque;
+use sync::Condvar;
+use sync::SpinNoIrqLock as Mutex;
 
 pub fn get_line() -> String {
     let mut s = String::new();
     loop {
-        let c = getchar();
+        let c = get_char();
         match c {
             '\u{7f}' /* '\b' */ => {
                 if s.pop().is_some() {
@@ -23,4 +26,31 @@ pub fn get_line() -> String {
             _ => {}
         }
     }
+}
+
+ #[derive(Default)]
+pub struct InputQueue {
+    buf: Mutex<VecDeque<char>>,
+    pushed: Condvar,
+}
+ impl InputQueue {
+    pub fn push(&self, c: char) {
+        self.buf.lock().push_back(c);
+        self.pushed.notify_one();
+    }
+    pub fn pop(&self) -> char {
+        loop {
+            let ret = self.buf.lock().pop_front();
+            match ret {
+                Some(c) => return c,
+                None => self.pushed._wait(),
+            }
+        }
+    }
+}
+ lazy_static! {
+    pub static ref CONSOLE_INPUT: InputQueue = InputQueue::default();
+}
+ pub fn get_char() -> char {
+    CONSOLE_INPUT.pop()
 }

kernel/src/trap.rs

@@ -5,10 +5,10 @@ use arch::cpu;
 pub static mut TICK: usize = 0;
 
 pub fn timer() {
-    processor().tick();
     if cpu::id() == 0 {
         unsafe { TICK += 1; }
     }
+    processor().tick();
     //info!("finish before return!");
 }
 
@@ -20,4 +20,8 @@ pub fn error(tf: &TrapFrame) -> ! {
     processor().manager().exit(pid, 0x100);
     processor().yield_now();
     unreachable!();
-}
+}
+
+pub fn serial(c: char) {
+    ::console::CONSOLE_INPUT.push(c);
+} 

riscv-pk/machine/uart16550.c

@@ -57,6 +57,8 @@ static void uart16550_done(const struct fdt_scan_node *node, void *extra)
   uart16550[1] = 0x00;    //                  (hi byte)
   uart16550[3] = 0x03;    // 8 bits, no parity, one stop bit
   uart16550[2] = 0xC7;    // Enable FIFO, clear them, with 14-byte threshold
+  uart16550[4] = 0x0B;
+  uart16550[1] = 0x01;    // Enable interrupt
 }
 
 void query_uart16550(uintptr_t fdt)