add net support

os/src/drivers/mod.rs

@@ -3,6 +3,7 @@ pub mod bus;
 pub mod chardev;
 pub mod gpu;
 pub mod input;
+pub mod net;
 pub mod plic;
 
 pub use block::BLOCK_DEVICE;
@@ -10,3 +11,4 @@ pub use bus::*;
 pub use chardev::UART;
 pub use gpu::*;
 pub use input::*;
+pub use net::*;

os/src/drivers/net/mod.rs

@@ -0,0 +1,41 @@
+use core::any::Any;
+
+use alloc::sync::Arc;
+use lazy_static::*;
+use virtio_drivers::{VirtIONet, VirtIOHeader};
+use crate::drivers::virtio::VirtioHal;
+use crate::sync::UPIntrFreeCell;
+
+const VIRTIO8: usize = 0x10004000;
+
+lazy_static! {
+    pub static ref NET_DEVICE: Arc<dyn NetDevice> = Arc::new(VirtIONetWrapper::new());
+}
+
+pub trait NetDevice: Send + Sync + Any {
+    fn transmit(&self, data: &[u8]);
+    fn receive(&self, data: &mut [u8]) -> usize;
+}
+
+pub struct VirtIONetWrapper(UPIntrFreeCell<VirtIONet<'static, VirtioHal>>);
+
+impl NetDevice for VirtIONetWrapper {
+    fn transmit(&self, data: &[u8]) {
+        self.0.exclusive_access().send(data).expect("can't send data")
+    }
+
+    fn receive(&self, data: &mut [u8]) -> usize {
+        self.0.exclusive_access().recv(data).expect("can't receive data")
+    }
+}
+
+impl VirtIONetWrapper {
+    pub fn new() -> Self {
+        unsafe {
+            let virtio =
+                VirtIONet::<VirtioHal>::new(&mut *(VIRTIO8 as *mut VirtIOHeader))
+                .expect("can't create net device by virtio");
+            VirtIONetWrapper(UPIntrFreeCell::new(virtio))
+        }
+    }
+}