sel4_stack/
lib.rs

1//
2// Copyright 2023, Colias Group, LLC
3//
4// SPDX-License-Identifier: BSD-2-Clause
5//
6
7#![no_std]
8
9use core::cell::UnsafeCell;
10
11#[repr(C)]
12#[cfg_attr(
13    any(
14        target_arch = "aarch64",
15        target_arch = "riscv32",
16        target_arch = "riscv64",
17        target_arch = "x86_64",
18    ),
19    repr(align(16))
20)]
21#[cfg_attr(target_arch = "arm", repr(align(4)))]
22pub struct Stack<const N: usize>(UnsafeCell<[u8; N]>);
23
24unsafe impl<const N: usize> Sync for Stack<N> {}
25
26impl<const N: usize> Stack<N> {
27    pub const fn new() -> Self {
28        Self(UnsafeCell::new([0; N]))
29    }
30
31    pub const fn bottom(&self) -> StackBottom {
32        StackBottom(self.0.get().cast::<u8>().wrapping_add(N))
33    }
34}
35
36impl<const N: usize> Default for Stack<N> {
37    fn default() -> Self {
38        Self::new()
39    }
40}
41
42#[repr(transparent)]
43pub struct StackBottom(*mut u8);
44
45impl StackBottom {
46    pub fn ptr(&self) -> *mut u8 {
47        self.0
48    }
49}
50
51unsafe impl Sync for StackBottom {}