WIP: Schemes

Makefile

@@ -10,7 +10,7 @@ bochs: build/harddrive.bin
 	bochs -f bochs.$(ARCH)
 
 qemu: build/harddrive.bin
-	qemu-system-$(ARCH) -serial mon:stdio -drive file=$<,format=raw,index=0,media=disk
+	qemu-system-$(ARCH) -serial mon:stdio -drive file=$<,format=raw,index=0,media=disk -nographic
 
 FORCE:
 

kernel/lib.rs

@@ -90,6 +90,9 @@ pub mod context;
 /// Intrinsics for panic handling
 pub mod panic;
 
+/// Schemes, filesystem handlers
+pub mod scheme;
+
 /// Syscall handlers
 pub mod syscall;
 
@@ -101,9 +104,9 @@ pub mod tests;
 pub extern fn kmain() {
     println!("TEST");
 
-    println!("{:?}", syscall::open(b"stdin", 0));
-    println!("{:?}", syscall::open(b"stdout", 0));
-    println!("{:?}", syscall::open(b"stderr", 0));
+    println!("{:?}", syscall::open(b"debug:", 0));
+    println!("{:?}", syscall::open(b"debug:", 0));
+    println!("{:?}", syscall::open(b"debug:", 0));
 
     loop {
         unsafe {

kernel/scheme/debug.rs

@@ -0,0 +1,33 @@
+use core::str;
+use syscall::Result;
+use super::Scheme;
+
+pub struct DebugScheme;
+
+impl Scheme for DebugScheme {
+    fn open(&mut self, path: &[u8], flags: usize) -> Result<usize> {
+        println!("DebugScheme::open: {}", unsafe { str::from_utf8_unchecked(path) });
+        Ok(0)
+    }
+
+    /// Read the file `number` into the `buffer`
+    ///
+    /// Returns the number of bytes read
+    fn read(&mut self, file: usize, buffer: &mut [u8]) -> Result<usize> {
+        Ok(0)
+    }
+
+    /// Write the `buffer` to the `file`
+    ///
+    /// Returns the number of bytes written
+    fn write(&mut self, file: usize, buffer: &[u8]) -> Result<usize> {
+        //TODO: Write bytes, do not convert to str
+        print!("{}", unsafe { str::from_utf8_unchecked(buffer) });
+        Ok(buffer.len())
+    }
+
+    /// Close the file `number`
+    fn close(&mut self, file: usize) -> Result<()> {
+        Ok(())
+    }
+}

kernel/scheme/mod.rs

@@ -1,12 +1,38 @@
-/// A scheme is a primitive for handling filesystem syscalls in Redox.
-/// Schemes accept paths from the kernel for `open`, and file descriptors that they generate
-/// are then passed for operations like `close`, `read`, `write`, etc.
-///
-/// The kernel validates paths and file descriptors before they are passed to schemes,
-/// also stripping the scheme identifier of paths if necessary.
+//! # Schemes
+//! A scheme is a primitive for handling filesystem syscalls in Redox.
+//! Schemes accept paths from the kernel for `open`, and file descriptors that they generate
+//! are then passed for operations like `close`, `read`, `write`, etc.
+//!
+//! The kernel validates paths and file descriptors before they are passed to schemes,
+//! also stripping the scheme identifier of paths if necessary.
+
+use syscall::Result;
+
+use self::debug::DebugScheme;
+
+/// Debug scheme
+pub mod debug;
+
+/// Schemes list
+pub static mut SCHEME: DebugScheme = DebugScheme;
+
+/// A scheme trait, implemented by a scheme handler
 pub trait Scheme {
     /// Open the file at `path` with `flags`.
     ///
     /// Returns a file descriptor or an error
-    fn open(path: &str, flags: usize) -> Result<usize>;
+    fn open(&mut self, path: &[u8], flags: usize) -> Result<usize>;
+
+    /// Read the file `number` into the `buffer`
+    ///
+    /// Returns the number of bytes read
+    fn read(&mut self, file: usize, buffer: &mut [u8]) -> Result<usize>;
+
+    /// Write the `buffer` to the `file`
+    ///
+    /// Returns the number of bytes written
+    fn write(&mut self, file: usize, buffer: &[u8]) -> Result<usize>;
+
+    /// Close the file `number`
+    fn close(&mut self, file: usize) -> Result<()>;
 }

kernel/syscall/fs.rs

@@ -1,5 +1,7 @@
 //! Filesystem syscalls
 
+use scheme::Scheme;
+
 use super::{Error, Result};
 
 /// Read syscall
@@ -27,9 +29,10 @@ pub fn write(fd: usize, buf: &[u8]) -> Result<usize> {
 /// Open syscall
 pub fn open(path: &[u8], flags: usize) -> Result<usize> {
     println!("Open {:?}: {:X}", ::core::str::from_utf8(path), flags);
+    let file = unsafe { &mut ::scheme::SCHEME }.open(path, flags)?;
     if let Some(fd) = unsafe { &mut ::context::CONTEXT }.add_file(::context::file::File {
         scheme: 0,
-        number: 0
+        number: file
     }) {
         Ok(fd)
     } else {