Better user programs with a special std. Sleep and exit are calling scheduler instead of wfi.

src/fs.rs

@@ -1,7 +1,33 @@
-use bffs::io::{IoBase, Read, Seek};
+use core::{cell::UnsafeCell, ops::Deref};
+
+use bffs::{
+    io::{IoBase, Read, Seek},
+    Fat32FileSystem,
+};
 
 const DISK_ADDR: *const u8 = 0x9000_0000 as *const _;
 
+pub struct FSTemp(UnsafeCell<Option<Fat32FileSystem<Disk>>>);
+unsafe impl Sync for FSTemp {}
+
+impl FSTemp {
+    pub unsafe fn init(&self) {
+        unsafe {
+            *self.0.get() = Some(Fat32FileSystem::new(Disk::new(1024 * 1024 * 16)).unwrap());
+        }
+    }
+}
+
+impl Deref for FSTemp {
+    type Target = Fat32FileSystem<Disk>;
+
+    fn deref(&self) -> &Self::Target {
+        unsafe { (&*self.0.get()).as_ref().unwrap_unchecked() }
+    }
+}
+
+pub static FILE_SYSTEM: FSTemp = FSTemp(UnsafeCell::new(None));
+
 #[derive(Debug)]
 pub struct Disk {
     pos: u64,