more scheduler rewrite

Author: thomasw04

machine/api/src/lib.rs

@@ -3,13 +3,15 @@
 use core::{fmt::Display, ops::Range};
 
 pub mod mem;
+pub mod stack;
 
 #[derive(Default, Debug, PartialEq, Eq, Clone)]
 pub enum Error {
     #[default]
     Generic,
     OutOfMemory(usize),
     OutOfBoundsPtr(usize, Range<usize>),
+    InvalidAddress(usize),
 }
 
 pub enum Fault {
@@ -30,7 +32,8 @@ impl Display for Error {
                     "Pointer {:p} out of bounds (expected in {:p}..{:p})",
                     *ptr as *const u8, range.start as *const u8, range.end as *const u8
                 )
-            }
+            },
+            Error::InvalidAddress(addr) => write!(f, "Invalid address {:p}", *addr as *const u8),
         }
     }
 }

machine/api/src/mem.rs

@@ -1,11 +1,12 @@
-
-pub mod stack;
+use core::ops::{Add, Sub, Div, Rem};
 
 #[repr(transparent)]
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd, Hash)]
 pub struct PhysAddr(usize);
 
 impl PhysAddr {
+    pub const MAX: Self = Self(usize::MAX);
+
     #[inline]
     pub fn new(addr: usize) -> Self {
         Self(addr)
@@ -15,6 +16,58 @@ impl PhysAddr {
     pub fn as_usize(&self) -> usize {
         self.0
     }
+
+    pub fn as_mut_ptr<T>(&self) -> *mut T {
+        self.0 as *mut T
+    }
+
+    pub fn checked_add(&self, other: usize) -> Option<Self> {
+        self.0.checked_add(other).map(Self)
+    }
+
+    pub fn checked_sub(&self, other: usize) -> Option<Self> {
+        self.0.checked_sub(other).map(Self)
+    }
+
+    pub fn is_multiple_of(&self, align: usize) -> bool {
+       self.0.is_multiple_of(align)
+    }
+}
+
+impl Add<usize> for PhysAddr {
+    type Output = Self;
+
+    #[inline]
+    fn add(self, rhs: usize) -> Self::Output {
+        Self(self.0 + rhs)
+    }
+}
+
+impl Sub<usize> for PhysAddr {
+    type Output = Self;
+
+    #[inline]
+    fn sub(self, rhs: usize) -> Self::Output {
+        Self(self.0 - rhs)
+    }
+}
+
+impl Div<usize> for PhysAddr {
+    type Output = Self;
+
+    #[inline]
+    fn div(self, rhs: usize) -> Self::Output {
+        Self(self.0 / rhs)
+    }
+}
+
+impl Rem<usize> for PhysAddr {
+    type Output = Self;
+
+    #[inline]
+    fn rem(self, rhs: usize) -> Self::Output {
+        Self(self.0 % rhs)
+    }
 }
 
 impl From<PhysAddr> for usize {
@@ -38,6 +91,16 @@ impl VirtAddr {
     pub fn as_usize(&self) -> usize {
         self.0
     }
+
+    #[inline]
+    pub fn saturating_add(&self, other: usize) -> Self {
+        Self(self.0.saturating_add(other))
+    }
+
+    #[inline]
+    pub fn saturating_sub(&self, other: usize) -> Self {
+        Self(self.0.saturating_sub(other))
+    }
 }
 
 impl From<VirtAddr> for usize {

machine/api/src/mem/stack.rs machine/api/src/stack.rsmachine/api/src/mem/stack.rs renamed to machine/api/src/stack.rs

@@ -1,18 +1,21 @@
 use core::{ffi::c_void, num::NonZero};
 use crate::{Result, mem::PhysAddr};
 
-pub struct StackDescriptor {
+pub type EntryFn = extern "C" fn();
+pub type FinFn = extern "C" fn() -> !;
+
+pub struct Descriptor {
     pub top: PhysAddr,
     pub size: NonZero<usize>,
-    pub entry: extern "C" fn(),
-    pub fin: Option<extern "C" fn() -> !>,
+    pub entry: EntryFn,
+    pub fin: Option<FinFn>,
 }
 
 pub trait Stacklike {
     type ElemSize: Copy;
     type StackPtr;
 
-    unsafe fn new(desc: StackDescriptor) -> Result<Self>
+    unsafe fn new(desc: Descriptor) -> Result<Self>
     where
         Self: Sized;
 

machine/arm/src/sched.rs

@@ -7,7 +7,7 @@ use core::{
     ptr::NonNull,
 };
 
-use hal_api::{Result, stack::StackDescriptor};
+use hal_api::{Result, stack::Descriptor};
 
 use crate::print::println;
 
@@ -191,19 +191,19 @@ impl hal_api::stack::Stacklike for ArmStack {
     type ElemSize = u32;
     type StackPtr = StackPtr;
 
-    unsafe fn new(desc: StackDescriptor) -> Result<Self>
+    unsafe fn new(desc: Descriptor) -> Result<Self>
     where
         Self: Sized,
     {
-        let StackDescriptor {
+        let Descriptor {
             top,
             size,
             entry,
             fin,
         } = desc;
 
         // We expect a PhysAddr, which can be converted to a ptr on nommu.
-        let top = NonNull::new(top as *mut u32).ok_or(hal_api::Error::InvalidAddress)?;
+        let top = NonNull::new(top.as_mut_ptr::<u32>()).ok_or(hal_api::Error::InvalidAddress(top.as_usize()))?;
 
         let mut stack = Self {
             top,

machine/testing/src/sched.rs

@@ -2,7 +2,7 @@ use std::ffi::c_void;
 
 use hal_api::{
     Result,
-    stack::{StackDescriptor, Stacklike},
+    stack::{Descriptor, Stacklike},
 };
 
 #[derive(Debug, Clone, Copy)]
@@ -12,7 +12,7 @@ impl Stacklike for TestingStack {
     type ElemSize = usize;
     type StackPtr = *mut c_void;
 
-    unsafe fn new(_desc: StackDescriptor) -> Result<Self>
+    unsafe fn new(_desc: Descriptor) -> Result<Self>
     where
         Self: Sized,
     {

options.toml

@@ -26,6 +26,12 @@ description = "Enables the Floating Point Unit (FPU). This is required for appli
 type = "Boolean"
 default = false
 
+[stackpages]
+name = "Stack Pages"
+description = "Number of pages to allocate for the kernel stack."
+type = { type = "Integer", min = 1 }
+default = 4
+
 [tuning.appmemsize]
 name = "Application Memory Size"
 description = "Sets the size of the initial memory region for the init application. This memory is used for the heap and stack."