fs: rework sysfs

Cargo.lock

@@ -458,6 +458,7 @@ dependencies = [
  "device-api",
  "discrete_range_map",
  "fdt-rs",
+ "libk",
  "libk-mm",
  "libk-util",
  "log",

kernel/driver/block/ahci/src/lib.rs

@@ -12,7 +12,7 @@ use device_api::{
     interrupt::{InterruptAffinity, InterruptHandler},
 };
 use error::AhciError;
-use libk::{devfs, device::manager::probe_partitions, task::runtime};
+use libk::{device::manager::probe_partitions, fs::devfs, task::runtime};
 use libk_mm::{address::AsPhysicalAddress, device::DeviceMemoryIo, PageBox};
 use libk_util::{sync::IrqSafeSpinlock, OneTimeInit};
 use port::AhciPort;

kernel/lib/device-tree/Cargo.toml

@@ -10,6 +10,7 @@ yggdrasil-abi.workspace = true
 device-api = { path = "../device-api", features = ["derive"] }
 libk-mm.workspace = true
 libk-util.workspace = true
+libk.workspace = true
 
 fdt-rs.workspace = true
 log.workspace = true

kernel/lib/device-tree/src/tree.rs

@@ -70,6 +70,11 @@ impl<'a> DeviceTree<'a> {
         self.tree.totalsize()
     }
 
+    /// Returns the underlying FDT blob bytes
+    pub fn as_bytes(&self) -> &'a [u8] {
+        self.tree.buf()
+    }
+
     /// Returns the root node of this device tree
     pub fn root(&self) -> TNode {
         self.index.root()
@@ -171,3 +176,5 @@ impl<'a> DeviceTree<'a> {
         DevTree::read_totalsize(header).map_err(|_| Error::InvalidArgument)
     }
 }
+
+unsafe impl Sync for DeviceTree<'_> {}

kernel/lib/device-tree/src/util.rs

@@ -1,5 +1,13 @@
 //! Utility functions for device tree handling
 use fdt_rs::index::iters::DevTreeIndexNodeSiblingIter;
+use libk::{
+    error::Error,
+    fs::sysfs::{
+        self,
+        attribute::{BytesAttribute, BytesAttributeOps},
+        object::KObject,
+    },
+};
 use libk_mm::{address::PhysicalAddress, phys::PhysicalMemoryRegion};
 
 use crate::{node::DeviceTreeNodeExt, property::DeviceTreePropertyRead, tree::DeviceTree};
@@ -44,3 +52,35 @@ impl Iterator for DeviceTreeMemoryRegionIter<'_> {
         }
     }
 }
+
+/// Registers sysfs objects related to the device tree
+pub fn create_sysfs_nodes(dt: &'static DeviceTree) {
+    struct Raw;
+
+    impl BytesAttributeOps for Raw {
+        type Data = &'static DeviceTree<'static>;
+        const NAME: &'static str = "raw";
+
+        fn read(state: &Self::Data, pos: usize, buffer: &mut [u8]) -> Result<usize, Error> {
+            let data = state.as_bytes();
+            if pos >= data.len() {
+                return Ok(0);
+            }
+            let amount = (data.len() - pos).min(buffer.len());
+            buffer[..amount].copy_from_slice(&data[pos..pos + amount]);
+            Ok(amount)
+        }
+
+        fn size(state: &Self::Data) -> usize {
+            state.size()
+        }
+    }
+
+    if let Some(device) = sysfs::device() {
+        let object = KObject::new(dt);
+
+        object.add_attribute(BytesAttribute::from(Raw)).ok();
+
+        device.add_object("device-tree", object).ok();
+    }
+}

kernel/lib/memtables/src/aarch64.rs

@@ -2,7 +2,7 @@ use bytemuck::{Pod, Zeroable};
 
 use crate::RawTable;
 
-pub const KERNEL_L3_COUNT: usize = 4;
+pub const KERNEL_L3_COUNT: usize = 8;
 
 #[derive(Clone, Copy, Pod, Zeroable)]
 #[repr(C)]

kernel/libk/src/debug.rs

@@ -5,10 +5,15 @@
 
 use core::{
     fmt::{self, Arguments},
+    str::FromStr,
     sync::atomic::{AtomicBool, Ordering},
 };
 
-use alloc::sync::Arc;
+use alloc::{
+    format,
+    string::{String, ToString},
+    sync::Arc,
+};
 use libk_util::{
     ring::RingBuffer,
     sync::{
@@ -19,7 +24,14 @@ use libk_util::{
 };
 use yggdrasil_abi::error::Error;
 
-use crate::task::{process::Process, thread::Thread};
+use crate::{
+    fs::sysfs::{
+        self,
+        attribute::{StringAttribute, StringAttributeOps},
+        object::KObject,
+    },
+    task::{process::Process, thread::Thread},
+};
 
 const MAX_DEBUG_SINKS: usize = 8;
 const RING_LOGGER_CAPACITY: usize = 65536;
@@ -116,6 +128,12 @@ impl DebugSinkWrapper {
             Self::Arc(level, _) => *level,
         }
     }
+
+    pub fn set_level(&mut self, target: LogLevel) {
+        match self {
+            Self::Arc(level, _) => *level = target,
+        }
+    }
 }
 
 impl log::Log for DebugSinkWrapper {
@@ -315,9 +333,51 @@ static DEBUG_SINKS: IrqSafeRwLock<StaticVector<DebugSinkWrapper, MAX_DEBUG_SINKS
 /// See [RingLoggerSink]
 pub static RING_LOGGER_SINK: RingLoggerSink = RingLoggerSink::new();
 
+fn make_sysfs_sink_object(index: usize) -> Arc<KObject<usize>> {
+    struct Level;
+
+    impl StringAttributeOps for Level {
+        type Data = usize;
+        const NAME: &'static str = "level";
+        const LIMIT: usize = 16;
+        const WRITEABLE: bool = true;
+
+        fn read(state: &Self::Data) -> Result<String, Error> {
+            let sinks = DEBUG_SINKS.read();
+            let sink = sinks.get(*state).ok_or(Error::InvalidFile)?;
+            Ok(sink.level().to_string())
+        }
+
+        fn write(state: &Self::Data, value: &str) -> Result<(), Error> {
+            let level = LogLevel::from_str(value)?;
+            let mut sinks = DEBUG_SINKS.write();
+            let sink = sinks.get_mut(*state).ok_or(Error::InvalidFile)?;
+            sink.set_level(level);
+            Ok(())
+        }
+    }
+
+    let object = KObject::new(index);
+
+    object.add_attribute(StringAttribute::from(Level)).ok();
+
+    object
+}
+
 /// Adds a debugging output sink
 pub fn add_sink(sink: Arc<dyn DebugSink>, level: LogLevel) {
-    DEBUG_SINKS.write().push(DebugSinkWrapper::Arc(level, sink));
+    let index = {
+        let mut sinks = DEBUG_SINKS.write();
+        let index = sinks.len();
+        sinks.push(DebugSinkWrapper::Arc(level, sink.clone()));
+        index
+    };
+
+    if let Some(debug) = sysfs::debug() {
+        debug
+            .add_object(format!("{index}"), make_sysfs_sink_object(index))
+            .ok();
+    }
 }
 
 pub fn add_serial_sink(sink: Arc<dyn DebugSink>, level: LogLevel) {
@@ -349,3 +409,34 @@ pub fn init() {
         .map(|_| log::set_max_level(log::LevelFilter::Trace))
         .ok();
 }
+
+impl fmt::Display for LogLevel {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let level = match self {
+            Self::Trace => "trace",
+            Self::Debug => "debug",
+            Self::Info => "info",
+            Self::Warning => "warn",
+            Self::Error => "error",
+            Self::Fatal => "fatal",
+        };
+
+        f.write_str(level)
+    }
+}
+
+impl FromStr for LogLevel {
+    type Err = Error;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "trace" | "t" => Ok(Self::Trace),
+            "debug" | "d" => Ok(Self::Debug),
+            "info" | "i" => Ok(Self::Info),
+            "warn" | "w" => Ok(Self::Warning),
+            "error" | "e" => Ok(Self::Error),
+            "fatal" | "f" => Ok(Self::Fatal),
+            _ => Err(Error::InvalidArgument),
+        }
+    }
+}

kernel/libk/src/device/manager.rs

@@ -10,7 +10,7 @@ use yggdrasil_abi::error::Error;
 
 use crate::{
     debug::{self, DebugSink, LogLevel},
-    devfs,
+    fs::devfs,
     vfs::NodeRef,
 };
 

kernel/libk/src/fs/mod.rs

@@ -0,0 +1,2 @@
+pub mod devfs;
+pub mod sysfs;

kernel/libk/src/fs/sysfs/attribute/bytes.rs

@@ -0,0 +1,128 @@
+use core::{any::Any, marker::PhantomData};
+
+use alloc::sync::Arc;
+use yggdrasil_abi::{
+    error::Error,
+    io::{FileMode, OpenOptions},
+};
+
+use crate::{
+    fs::sysfs::object::KObject,
+    vfs::{CommonImpl, InstanceData, Node, NodeFlags, NodeRef, RegularImpl},
+};
+
+use super::Attribute;
+
+pub trait BytesAttributeOps: Send + Sync + 'static {
+    type Data: Send + 'static = ();
+    const NAME: &'static str;
+    const WRITEABLE: bool = false;
+
+    fn read(state: &Self::Data, pos: usize, buffer: &mut [u8]) -> Result<usize, Error> {
+        let _ = state;
+        let _ = pos;
+        let _ = buffer;
+        Err(Error::NotImplemented)
+    }
+
+    fn write(state: &Self::Data, pos: usize, buffer: &[u8]) -> Result<usize, Error> {
+        let _ = state;
+        let _ = pos;
+        let _ = buffer;
+        Err(Error::ReadOnly)
+    }
+
+    fn size(state: &Self::Data) -> usize {
+        let _ = state;
+        0
+    }
+}
+
+pub struct BytesAttribute<V: BytesAttributeOps>(PhantomData<V>);
+
+struct BytesAttributeNode<V: BytesAttributeOps> {
+    object: Arc<KObject<V::Data>>,
+    _pd: PhantomData<V>,
+}
+
+impl<V: BytesAttributeOps> CommonImpl for BytesAttributeNode<V> {
+    fn size(&self, _node: &NodeRef) -> Result<u64, Error> {
+        Ok(V::size(&self.object.data) as u64)
+    }
+
+    fn as_any(&self) -> &dyn Any {
+        self as _
+    }
+}
+
+impl<V: BytesAttributeOps> RegularImpl for BytesAttributeNode<V> {
+    fn open(
+        &self,
+        _node: &NodeRef,
+        opts: OpenOptions,
+    ) -> Result<(u64, Option<InstanceData>), Error> {
+        if opts.contains(OpenOptions::WRITE) && !V::WRITEABLE {
+            return Err(Error::ReadOnly);
+        }
+
+        Ok((0, None))
+    }
+
+    fn close(&self, _node: &NodeRef, _instance: Option<&InstanceData>) -> Result<(), Error> {
+        Ok(())
+    }
+
+    fn read(
+        &self,
+        _node: &NodeRef,
+        _instance: Option<&InstanceData>,
+        pos: u64,
+        buf: &mut [u8],
+    ) -> Result<usize, Error> {
+        let pos = pos.try_into().map_err(|_| Error::InvalidArgument)?;
+        V::read(&self.object.data, pos, buf)
+    }
+
+    fn write(
+        &self,
+        _node: &NodeRef,
+        _instance: Option<&InstanceData>,
+        pos: u64,
+        buf: &[u8],
+    ) -> Result<usize, Error> {
+        let pos = pos.try_into().map_err(|_| Error::InvalidArgument)?;
+        V::write(&self.object.data, pos, buf)
+    }
+
+    fn truncate(&self, _node: &NodeRef, _new_size: u64) -> Result<(), Error> {
+        Ok(())
+    }
+}
+
+impl<V: BytesAttributeOps> From<V> for BytesAttribute<V> {
+    fn from(_value: V) -> Self {
+        Self(PhantomData)
+    }
+}
+
+impl<V: BytesAttributeOps> Attribute<V::Data> for BytesAttribute<V> {
+    fn instantiate(&self, parent: &Arc<KObject<V::Data>>) -> Result<NodeRef, Error> {
+        let mode = match V::WRITEABLE {
+            false => FileMode::new(0o444),
+            true => FileMode::new(0o644),
+        };
+
+        Ok(Node::regular_kernel(
+            BytesAttributeNode {
+                object: parent.clone(),
+                _pd: PhantomData::<V>,
+            },
+            NodeFlags::IN_MEMORY_PROPS,
+            mode,
+        ))
+    }
+
+    fn name(&self) -> &str {
+        V::NAME
+    }
+}

kernel/libk/src/fs/sysfs/attribute/mod.rs

@@ -0,0 +1,17 @@
+use alloc::sync::Arc;
+use yggdrasil_abi::error::Error;
+
+use crate::vfs::NodeRef;
+
+use super::object::KObject;
+
+mod bytes;
+mod string;
+
+pub trait Attribute<D>: Sync + Send {
+    fn instantiate(&self, parent: &Arc<KObject<D>>) -> Result<NodeRef, Error>;
+    fn name(&self) -> &str;
+}
+
+pub use bytes::{BytesAttribute, BytesAttributeOps};
+pub use string::{StringAttribute, StringAttributeOps};

kernel/libk/src/fs/sysfs/attribute/string.rs

@@ -0,0 +1,193 @@
+use core::{
+    any::Any,
+    marker::PhantomData,
+    sync::atomic::{AtomicBool, Ordering},
+};
+
+use alloc::{string::String, sync::Arc, vec::Vec};
+use libk_util::sync::spin_rwlock::IrqSafeRwLock;
+use yggdrasil_abi::{
+    error::Error,
+    io::{FileMode, OpenOptions},
+};
+
+use crate::{
+    fs::sysfs::object::KObject,
+    vfs::{CommonImpl, InstanceData, Node, NodeFlags, NodeRef, RegularImpl},
+};
+
+use super::Attribute;
+
+pub trait StringAttributeOps: Sync + Send + 'static {
+    type Data: Send + 'static = ();
+
+    const WRITEABLE: bool = false;
+    const NAME: &'static str;
+    const LIMIT: usize = 4096;
+
+    fn read(state: &Self::Data) -> Result<String, Error> {
+        let _ = state;
+        Err(Error::NotImplemented)
+    }
+    fn write(state: &Self::Data, value: &str) -> Result<(), Error> {
+        let _ = state;
+        let _ = value;
+        Err(Error::ReadOnly)
+    }
+}
+
+pub struct StringAttribute<V: StringAttributeOps>(PhantomData<V>);
+
+struct StringAttributeNode<V: StringAttributeOps> {
+    object: Arc<KObject<V::Data>>,
+    _pd: PhantomData<V>,
+}
+
+struct StringAttributeState {
+    value: IrqSafeRwLock<Vec<u8>>,
+    modified: AtomicBool,
+}
+
+impl<V: StringAttributeOps> CommonImpl for StringAttributeNode<V> {
+    fn size(&self, _node: &NodeRef) -> Result<u64, Error> {
+        Ok(0)
+    }
+
+    fn as_any(&self) -> &dyn Any {
+        self as _
+    }
+}
+
+impl<V: StringAttributeOps> RegularImpl for StringAttributeNode<V> {
+    fn open(
+        &self,
+        _node: &NodeRef,
+        opts: OpenOptions,
+    ) -> Result<(u64, Option<InstanceData>), Error> {
+        if opts.contains(OpenOptions::WRITE) && !V::WRITEABLE {
+            return Err(Error::ReadOnly);
+        }
+
+        let mut value = V::read(self.object.data())?.into_bytes();
+        value.push(b'\n');
+
+        let instance = StringAttributeState {
+            value: IrqSafeRwLock::new(value),
+            modified: AtomicBool::new(false),
+        };
+
+        Ok((0, Some(Arc::new(instance))))
+    }
+
+    fn close(&self, _node: &NodeRef, instance: Option<&InstanceData>) -> Result<(), Error> {
+        if V::WRITEABLE {
+            let instance = instance.ok_or(Error::InvalidFile)?;
+            let instance = instance
+                .downcast_ref::<StringAttributeState>()
+                .ok_or(Error::InvalidFile)?;
+
+            if instance.modified.load(Ordering::Acquire) {
+                let value = instance.value.read();
+                let value_str =
+                    core::str::from_utf8(&value[..]).map_err(|_| Error::InvalidArgument)?;
+
+                // Trim whitespace and newlines
+                V::write(&self.object.data, value_str.trim())?;
+            }
+        }
+
+        Ok(())
+    }
+
+    fn read(
+        &self,
+        _node: &NodeRef,
+        instance: Option<&InstanceData>,
+        pos: u64,
+        buf: &mut [u8],
+    ) -> Result<usize, Error> {
+        let instance = instance.ok_or(Error::InvalidFile)?;
+        let instance = instance
+            .downcast_ref::<StringAttributeState>()
+            .ok_or(Error::InvalidFile)?;
+
+        let value = instance.value.read();
+        let len = value.len();
+        if pos >= len as u64 {
+            return Ok(0);
+        }
+        let pos = pos as usize;
+        let amount = (len - pos).min(buf.len());
+        buf[..amount].copy_from_slice(&value[pos..pos + amount]);
+
+        Ok(amount)
+    }
+
+    fn write(
+        &self,
+        _node: &NodeRef,
+        instance: Option<&InstanceData>,
+        pos: u64,
+        buf: &[u8],
+    ) -> Result<usize, Error> {
+        if !V::WRITEABLE {
+            return Err(Error::InvalidFile);
+        }
+        let instance = instance.ok_or(Error::InvalidFile)?;
+        let instance = instance
+            .downcast_ref::<StringAttributeState>()
+            .ok_or(Error::InvalidFile)?;
+
+        let mut value = instance.value.write();
+
+        let pos: usize = pos.try_into().map_err(|_| Error::InvalidFile)?;
+        if pos > value.len() {
+            return Err(Error::InvalidArgument);
+        }
+        if pos + buf.len() > V::LIMIT {
+            return Err(Error::InvalidArgument);
+        }
+
+        let amount_copy = (value.len() - pos).min(buf.len());
+
+        value[pos..pos + amount_copy].copy_from_slice(&buf[..amount_copy]);
+        if amount_copy < buf.len() {
+            value.extend_from_slice(&buf[amount_copy..]);
+        }
+        instance.modified.store(true, Ordering::Release);
+
+        Ok(buf.len())
+    }
+
+    fn truncate(&self, _node: &NodeRef, _new_size: u64) -> Result<(), Error> {
+        Ok(())
+    }
+}
+
+impl<V: StringAttributeOps> From<V> for StringAttribute<V> {
+    fn from(_value: V) -> Self {
+        Self(PhantomData)
+    }
+}
+
+impl<V: StringAttributeOps> Attribute<V::Data> for StringAttribute<V> {
+    fn instantiate(&self, parent: &Arc<KObject<V::Data>>) -> Result<Arc<Node>, Error> {
+        let mode = match V::WRITEABLE {
+            false => FileMode::new(0o444),
+            true => FileMode::new(0o644),
+        };
+
+        Ok(Node::regular_kernel(
+            StringAttributeNode {
+                object: parent.clone(),
+                _pd: PhantomData::<V>,
+            },
+            NodeFlags::IN_MEMORY_PROPS,
+            mode,
+        ))
+    }
+
+    fn name(&self) -> &str {
+        V::NAME
+    }
+}

kernel/libk/src/fs/sysfs/mod.rs

@@ -0,0 +1,30 @@
+use alloc::sync::Arc;
+use libk_util::OneTimeInit;
+use object::KObject;
+
+use crate::vfs::NodeRef;
+
+pub mod attribute;
+pub mod object;
+
+static ROOT: OneTimeInit<NodeRef> = OneTimeInit::new();
+
+pub fn root() -> &'static NodeRef {
+    ROOT.get()
+}
+
+pub fn kernel() -> Option<&'static Arc<KObject<()>>> {
+    object::KERNEL_OBJECT.try_get()
+}
+
+pub fn debug() -> Option<&'static Arc<KObject<()>>> {
+    object::DEBUG_OBJECT.try_get()
+}
+
+pub fn device() -> Option<&'static Arc<KObject<()>>> {
+    object::DEVICE_OBJECT.try_get()
+}
+
+pub fn init() {
+    ROOT.init(object::setup_fixed_objects());
+}

kernel/libk/src/fs/sysfs/object.rs

@@ -0,0 +1,69 @@
+use alloc::{string::String, sync::Arc};
+use libk_util::OneTimeInit;
+use yggdrasil_abi::{error::Error, io::FileMode};
+
+use crate::vfs::{impls::MemoryDirectory, Node, NodeFlags};
+
+use super::attribute::Attribute;
+
+pub struct KObject<D> {
+    pub(super) data: D,
+    pub(super) node: Arc<Node>,
+}
+
+impl<D> KObject<D> {
+    pub fn new(data: D) -> Arc<Self> {
+        let node = Node::directory_kernel(
+            MemoryDirectory,
+            NodeFlags::IN_MEMORY_SIZE | NodeFlags::IN_MEMORY_PROPS,
+            FileMode::new(0o555),
+        );
+        Arc::new(Self { data, node })
+    }
+
+    pub fn add_attribute<A: Attribute<D>>(self: &Arc<Self>, attribute: A) -> Result<(), Error> {
+        let node = attribute.instantiate(self)?;
+        self.node.add_child(attribute.name(), node)?;
+        Ok(())
+    }
+
+    pub fn add_object<S: Into<String>, T>(
+        &self,
+        name: S,
+        child: Arc<KObject<T>>,
+    ) -> Result<(), Error> {
+        self.node.add_child(name, child.node.clone())
+    }
+
+    pub(super) fn data(&self) -> &D {
+        &self.data
+    }
+}
+
+unsafe impl<D: Send> Send for KObject<D> {}
+unsafe impl<D: Send> Sync for KObject<D> {}
+
+// Static, fixed objects
+// `/`
+pub static ROOT_OBJECT: OneTimeInit<Arc<KObject<()>>> = OneTimeInit::new();
+// `/kernel`
+pub static KERNEL_OBJECT: OneTimeInit<Arc<KObject<()>>> = OneTimeInit::new();
+// `/device`
+pub static DEVICE_OBJECT: OneTimeInit<Arc<KObject<()>>> = OneTimeInit::new();
+// `/debug`
+pub static DEBUG_OBJECT: OneTimeInit<Arc<KObject<()>>> = OneTimeInit::new();
+
+fn setup_fixed_object(root: &Arc<KObject<()>>, obj: &OneTimeInit<Arc<KObject<()>>>, name: &str) {
+    let obj = obj.init(KObject::new(()));
+    root.add_object(name, obj.clone()).ok();
+}
+
+pub fn setup_fixed_objects() -> Arc<Node> {
+    let root = ROOT_OBJECT.init(KObject::new(()));
+
+    setup_fixed_object(root, &KERNEL_OBJECT, "kernel");
+    setup_fixed_object(root, &DEVICE_OBJECT, "device");
+    setup_fixed_object(root, &DEBUG_OBJECT, "debug");
+
+    root.node.clone()
+}

kernel/libk/src/lib.rs

@@ -36,8 +36,8 @@ pub mod task;
 
 pub mod arch;
 pub mod debug;
-pub mod devfs;
 pub mod device;
+pub mod fs;
 pub mod module;
 pub mod random;
 pub mod time;

kernel/libk/src/vfs/node/mod.rs

@@ -175,14 +175,30 @@ impl Node {
         (master, slave)
     }
 
-    /// Creates a new directory node with given [DirectoryImpl]
-    pub fn directory<T: DirectoryImpl + 'static>(data: T, flags: NodeFlags) -> NodeRef {
+    /// Creates a new directory node with given [DirectoryImpl] and permissions
+    pub fn directory_kernel<T: DirectoryImpl + 'static>(
+        data: T,
+        flags: NodeFlags,
+        mode: FileMode,
+    ) -> NodeRef {
         let data = NodeImpl::Directory(DirectoryData {
             imp: Box::new(data),
             mountpoint: IrqSafeSpinlock::new(None),
             children: IrqSafeSpinlock::new(Vec::new()),
         });
-        Self::new(data, flags, Metadata::default_dir())
+        Self::new(
+            data,
+            flags,
+            Metadata {
+                mode,
+                ..Metadata::default_dir()
+            },
+        )
+    }
+
+    /// Creates a new directory node with given [DirectoryImpl]
+    pub fn directory<T: DirectoryImpl + 'static>(data: T, flags: NodeFlags) -> NodeRef {
+        Self::directory_kernel(data, flags, FileMode::default_dir())
     }
 
     /// Creates a new file node with given [RegularImpl] and permissions
@@ -196,11 +212,7 @@ impl Node {
             flags,
             Metadata {
                 mode,
-                uid: UserId::root(),
-                gid: GroupId::root(),
-                block_size: 0,
-                block_count: 0,
-                inode: None,
+                ..Metadata::default_file()
             },
         )
     }

kernel/src/arch/aarch64/boot/mod.rs

@@ -13,7 +13,10 @@ use kernel_arch_aarch64::{
     mem::{self, table::L3},
     CPU_COUNT,
 };
-use libk::{devfs, task::runtime};
+use libk::{
+    fs::{devfs, sysfs},
+    task::runtime,
+};
 use libk_mm::{
     address::{PhysicalAddress, Virtualize},
     phys,
@@ -121,6 +124,7 @@ unsafe extern "C" fn __aarch64_bsp_upper_entry(dtb: PhysicalAddress) -> ! {
 
     exception::init_exceptions();
 
+    sysfs::init();
     devfs::init();
 
     runtime::init_task_queue();

kernel/src/arch/aarch64/mod.rs

@@ -284,6 +284,9 @@ impl AArch64 {
 
             let dt = self.dt.get();
 
+            // Create device tree sysfs nodes
+            device_tree::util::create_sysfs_nodes(dt);
+
             let (machine_compatible, machine_name) = Self::machine_name(dt);
 
             if let Some(compatible) = machine_compatible {

kernel/src/device/serial/pl011.rs

@@ -158,7 +158,7 @@ impl Device for Pl011 {
 
         DEVICE_REGISTRY
             .serial_terminal
-            .register(terminal.clone(), Some((self.clone(), LogLevel::Debug)))
+            .register(terminal.clone(), Some((self.clone(), LogLevel::Info)))
             .ok();
 
         Ok(())

kernel/src/fs/mod.rs

@@ -5,7 +5,8 @@ use core::ptr::NonNull;
 use abi::path::Path;
 use ext2::Ext2Fs;
 use libk::{
-    block, devfs,
+    block,
+    fs::{devfs, sysfs},
     vfs::{self, register_root, IoContext, NodeRef},
 };
 use libk_mm::{
@@ -21,7 +22,7 @@ use yggdrasil_abi::{error::Error, io::MountOptions};
 pub use pseudo::add_pseudo_devices;
 
 pub mod pseudo;
-pub mod sysfs;
+// pub mod sysfs;
 
 /// Describes in-memory filesystem image used as initial root
 pub struct Initrd {

kernel/src/fs/pseudo.rs

@@ -6,8 +6,8 @@ use alloc::{boxed::Box, sync::Arc};
 use async_trait::async_trait;
 use device_api::device::Device;
 use libk::{
-    devfs,
     device::char::CharDevice,
+    fs::devfs,
     random,
     vfs::{impls::read_fn_node, FileReadiness},
 };

kernel/src/fs/sysfs.rs

@@ -1,112 +0,0 @@
-//! "System" filesystem implementation
-
-use core::sync::atomic::Ordering;
-
-use abi::error::Error;
-use alloc::{format, string::String};
-use git_version::git_version;
-use kernel_arch_interface::cpu::CpuFeatureSet;
-use libk::{
-    arch::Cpu,
-    debug,
-    task::{cpu_count, sched},
-    vfs::{
-        impls::{const_value_node, mdir, read_fn_node, ReadOnlyFnValueNode},
-        NodeRef,
-    },
-};
-use libk_mm::phys;
-use libk_util::OneTimeInit;
-
-use crate::util;
-
-static ROOT: OneTimeInit<NodeRef> = OneTimeInit::new();
-
-/// Returns the root of the filesystem
-pub fn root() -> &'static NodeRef {
-    ROOT.get()
-}
-
-fn read_kernel_log(pos: u64, buffer: &mut [u8]) -> Result<usize, Error> {
-    Ok(debug::RING_LOGGER_SINK.read(pos as usize, buffer))
-}
-
-fn feature_list<C: CpuFeatureSet>(features: Option<&C>) -> String {
-    let mut list = String::new();
-    if let Some(features) = features {
-        let mut cnt = 0;
-        features.iter().for_each(|feature| {
-            if cnt != 0 {
-                list.push(' ');
-            }
-            list.push_str(feature);
-            cnt += 1;
-        });
-    }
-    list
-}
-
-fn sched_stats() -> String {
-    let mut res = String::new();
-    for i in 0..cpu_count() {
-        let stats = sched::stats(i);
-        res.push_str(&format!(
-            "{} {} {} {}",
-            stats.idle.load(Ordering::Relaxed),
-            stats.user.load(Ordering::Relaxed),
-            stats.kernel.load(Ordering::Relaxed),
-            stats.total.load(Ordering::Relaxed)
-        ));
-    }
-    res
-}
-
-/// Sets up the entries within the filesystem
-pub fn init() {
-    let d_kernel = mdir([
-        ("version", const_value_node(env!("CARGO_PKG_VERSION"))),
-        ("rev", const_value_node(git_version!())),
-        ("log", read_fn_node(read_kernel_log)),
-    ]);
-    let d_proc = mdir([(
-        "sched_stats",
-        ReadOnlyFnValueNode::new_node(|| Ok(sched_stats())),
-    )]);
-    let d_mem_phys = mdir([
-        (
-            "total_pages",
-            ReadOnlyFnValueNode::new_node(|| Ok(phys::stats().total_usable_pages)),
-        ),
-        (
-            "free_pages",
-            ReadOnlyFnValueNode::new_node(|| Ok(phys::stats().free_pages)),
-        ),
-        (
-            "allocated_pages",
-            ReadOnlyFnValueNode::new_node(|| Ok(phys::stats().allocated_pages)),
-        ),
-    ]);
-    let d_mem = mdir([("phys", d_mem_phys)]);
-    // TODO per-CPU entries
-    let d_cpu_features = mdir([
-        (
-            "enabled",
-            ReadOnlyFnValueNode::new_node(|| Ok(feature_list(Cpu::local().enabled_features()))),
-        ),
-        (
-            "available",
-            ReadOnlyFnValueNode::new_node(|| Ok(feature_list(Cpu::local().available_features()))),
-        ),
-    ]);
-    let d_cpu = mdir([("features", d_cpu_features)]);
-    let root = mdir([
-        ("kernel", d_kernel),
-        ("cpu", d_cpu),
-        ("mem", d_mem),
-        ("proc", d_proc),
-        ("arch", const_value_node(util::arch_str())),
-        ("machine", const_value_node(util::machine_name())),
-    ]);
-
-    ROOT.init(root);
-}

kernel/src/init.rs

@@ -2,8 +2,8 @@
 
 use abi::error::Error;
 use libk::{
-    devfs,
     device::display::console,
+    fs::devfs,
     random,
     task::{binary::LoadOptions, process::Process, runtime, thread::Thread},
     vfs::{impls::fn_symlink, IoContext, NodeRef},

kernel/src/main.rs

@@ -20,7 +20,8 @@
     exact_size_is_empty,
     maybe_uninit_uninit_array,
     never_type,
-    format_args_nl
+    format_args_nl,
+    associated_type_defaults
 )]
 #![allow(
     clippy::new_without_default,
@@ -34,12 +35,21 @@
 #![no_std]
 #![no_main]
 
-use alloc::borrow::ToOwned;
+use abi::error::Error;
+use alloc::{borrow::ToOwned, string::String};
 use arch::Platform;
-use fs::sysfs;
 use git_version::git_version;
 use kernel_arch::{Architecture, ArchitectureImpl};
-use libk::{arch::Cpu, devfs};
+use libk::{
+    arch::Cpu,
+    fs::{
+        devfs,
+        sysfs::{
+            self,
+            attribute::{StringAttribute, StringAttributeOps},
+        },
+    },
+};
 use libk_util::sync::SpinFence;
 
 use crate::{arch::PLATFORM, task::spawn_kernel_closure};
@@ -47,6 +57,7 @@ use crate::{arch::PLATFORM, task::spawn_kernel_closure};
 extern crate yggdrasil_abi as abi;
 
 extern crate alloc;
+#[cfg(not(rust_analyzer))]
 extern crate compiler_builtins;
 
 #[macro_use]
@@ -75,6 +86,32 @@ pub fn kernel_secondary_main() -> ! {
     }
 }
 
+fn register_sysfs_attributes() {
+    struct Version;
+    struct Arch;
+
+    impl StringAttributeOps for Version {
+        const NAME: &'static str = "version";
+
+        fn read(_state: &Self::Data) -> Result<String, Error> {
+            Ok(git_version!().into())
+        }
+    }
+
+    impl StringAttributeOps for Arch {
+        const NAME: &'static str = "arch";
+
+        fn read(_state: &Self::Data) -> Result<String, Error> {
+            Ok(util::arch_str().into())
+        }
+    }
+
+    let kernel = sysfs::kernel().unwrap();
+
+    kernel.add_attribute(StringAttribute::from(Version)).ok();
+    kernel.add_attribute(StringAttribute::from(Arch)).ok();
+}
+
 /// Common kernel main function. Must be called for BSP processor only.
 ///
 /// # Prerequisites
@@ -103,7 +140,7 @@ pub fn kernel_main() -> ! {
     Cpu::init_ipi_queues(ArchitectureImpl::cpu_count());
 
     // Setup the sysfs
-    sysfs::init();
+    register_sysfs_attributes();
     fs::add_pseudo_devices().unwrap();
 
     // Wait until all APs initialize