Rename scheduling to 'async_io', general cleanup

kernel/src/main.rs

@@ -5,8 +5,8 @@ extern crate alloc;
 
 use libk::{
     drivers::{
+        async_io::task::{Executor, Task},
         io,
-        scheduling::task::{Executor, Task},
     },
     prelude::*,
     util::shell::shell,

libk/src/drivers/async_io/task.rs

@@ -1,3 +1,8 @@
+//! Allows creation of asynchronous IO bound tasks.
+//!
+//! Written by @zxq5 for the most part with code from
+//! [here](https://github.com/phil-opp/blog_os/).
+//!
 use crate::prelude::*;
 use alloc::collections::BTreeMap;
 use alloc::sync::Arc;

libk/src/drivers/mod.rs

@@ -1,3 +1,3 @@
+pub mod async_io;
 pub mod io;
 pub mod kalloc;
-pub mod scheduling;

libk/src/lib.rs

@@ -1,5 +1,5 @@
 #![no_std]
-#![allow(async_fn_in_trait)]
+// #![allow(async_fn_in_trait)]
 #![warn(tail_expr_drop_order)]
 #![warn(
     clippy::correctness,
@@ -12,15 +12,11 @@
     rustdoc::missing_panics_doc
 )]
 
-// alloc
-// io : serial, framebuffer, ascii(?), keyboard
-// ?????
-// scheduling / tasks : async
-
 extern crate alloc;
 
 pub mod drivers;
 pub mod resources;
+pub mod threads;
 pub mod util;
 
 #[allow(unused)] // We aren't using much of this right now.

libk/src/std/application.rs

@@ -7,7 +7,10 @@ mod window;
 pub trait Application {
     type Output;
 
-    async fn run(&mut self, args: Vec<String>) -> Result<Self::Output, Error>;
+    fn run(
+        &mut self,
+        args: Vec<String>,
+    ) -> impl core::future::Future<Output = Result<Self::Output, Error>> + Send;
 }
 
 #[derive(Debug)]

libk/src/std/io/mod.rs

@@ -1,2 +0,0 @@
-mod io;
-pub use io::*;

libk/src/threads.rs

@@ -0,0 +1,113 @@
+use core::arch::asm;
+
+#[repr(C)]
+pub struct Thread {
+    id: usize,
+    /// This shall be default before the program is interrupted, otherwise it will store
+    /// CPU registers etc to be restored on context switch.
+    ctx: ThreadContext,
+}
+
+/// CPU state to be saved on context switches.
+#[repr(C)]
+#[derive(Default)]
+pub struct ThreadContext {
+    /// Accumulator register.
+    rax: u64,
+    /// Base register.
+    rbx: u64,
+    /// Counter register.
+    rcx: u64,
+    /// Data register.
+    rdx: u64,
+    /// Source index register.
+    rsi: u64,
+    /// Destination index register.
+    rdi: u64,
+    /// Base pointer register.
+    rbp: u64,
+    /// Stack pointer register.
+    rsp: u64,
+    /// An extended register.
+    r8: u64,
+    /// An extended register.
+    r9: u64,
+    /// An extended register.
+    r10: u64,
+    /// An extended register.
+    r11: u64,
+    /// An extended register.
+    r12: u64,
+    /// An extended register.
+    r13: u64,
+    /// An extended register.
+    r14: u64,
+    /// An extended register.
+    r15: u64,
+    /// The instruction pointer.
+    rip: u64,
+    /// RFLAGS register.
+    rflags: u64,
+}
+
+impl ThreadContext {
+    /// Saves the current registers of the CPU before a context switch
+    /// to be restored later.
+    ///
+    /// # Notes
+    ///
+    /// This function should ONLY be called in interrupt handlers such
+    /// as that of the timer. This will then save registers as required
+    ///
+    ///
+    /// # Safety
+    ///
+    /// This function is unsafe because of the usage of inline ASM.
+    #[inline(always)]
+    pub unsafe fn save_registers() -> Self {
+        let mut context = Self::default();
+        unsafe {
+            asm!(
+                "mov {0}, rax",
+                "mov {1}, rbx",
+                "mov {2}, rcx",
+                "mov {3}, rdx",
+                "mov {4}, rsi",
+                "mov {5}, rdi",
+                "mov {6}, rbp",
+                "mov {7}, rsp",
+                "mov {8}, r8",
+                "mov {9}, r9",
+                "mov {10}, r10",
+                "mov {11}, r11",
+                "mov {12}, r12",
+                "mov {13}, r13",
+                "mov {14}, r14",
+                "mov {15}, r15",
+                "lea {16}, [rip]",
+                "pushf",
+                "pop {17}",
+                out(reg) context.rax,
+                out(reg) context.rbx,
+                out(reg) context.rcx,
+                out(reg) context.rdx,
+                out(reg) context.rsi,
+                out(reg) context.rdi,
+                out(reg) context.rbp,
+                out(reg) context.rsp,
+                out(reg) context.r8,
+                out(reg) context.r9,
+                out(reg) context.r10,
+                out(reg) context.r11,
+                out(reg) context.r12,
+                out(reg) context.r13,
+                out(reg) context.r14,
+                out(reg) context.r15,
+                out(reg) context.rip,
+                out(reg) context.rflags,
+            );
+        }
+
+        context
+    }
+}

libk/src/util/shell.rs

@@ -1,4 +1,4 @@
-use x86_64::registers::rflags::read;
+// use x86_64::registers::rflags::read;
 
 use crate::{drivers::io::ascii::clear_screen, prelude::stdin::read_line, print, println};