Add memory scheme, implement fstatvfs

scheme/memory.rs

@@ -0,0 +1,30 @@
+use arch::memory::{free_frames, used_frames};
+
+use syscall::data::StatVfs;
+use syscall::error::*;
+use syscall::scheme::Scheme;
+
+pub struct MemoryScheme;
+
+impl Scheme for MemoryScheme {
+    fn open(&self, _path: &[u8], _flags: usize, _uid: u32, _gid: u32) -> Result<usize> {
+        Ok(0)
+    }
+
+    fn fstatvfs(&self, _file: usize, stat: &mut StatVfs) -> Result<usize> {
+        let used = used_frames() as u64;
+        let free = free_frames() as u64;
+
+        stat.f_bsize = 4096;
+        stat.f_blocks = used + free;
+        stat.f_bfree = free;
+        stat.f_bavail = stat.f_bfree;
+
+        Ok(0)
+    }
+
+    /// Close the file `number`
+    fn close(&self, _file: usize) -> Result<usize> {
+        Ok(0)
+    }
+}

scheme/mod.rs

@@ -20,6 +20,7 @@ use self::event::EventScheme;
 use self::env::EnvScheme;
 use self::initfs::InitFsScheme;
 use self::irq::IrqScheme;
+use self::memory::MemoryScheme;
 use self::null::NullScheme;
 use self::pipe::PipeScheme;
 use self::root::RootScheme;
@@ -45,6 +46,9 @@ pub mod irq;
 #[cfg(feature="live")]
 pub mod live;
 
+/// `memory:` - a scheme for accessing physical memory
+pub mod memory;
+
 /// `null:` - a scheme that will discard all writes, and read no bytes
 pub mod null;
 
@@ -124,6 +128,7 @@ impl SchemeList {
         self.insert(ns, Box::new(*b"debug"), |scheme_id| Arc::new(Box::new(DebugScheme::new(scheme_id)))).unwrap();
         self.insert(ns, Box::new(*b"initfs"), |_| Arc::new(Box::new(InitFsScheme::new()))).unwrap();
         self.insert(ns, Box::new(*b"irq"), |scheme_id| Arc::new(Box::new(IrqScheme::new(scheme_id)))).unwrap();
+        self.insert(ns, Box::new(*b"memory"), |_| Arc::new(Box::new(MemoryScheme))).unwrap();
         self.insert(ns, Box::new(*b"pipe"), |scheme_id| Arc::new(Box::new(PipeScheme::new(scheme_id)))).unwrap();
     }