jonaskruckenberg.de
Next Generation WASM Microkernel Operating System
1// Copyright 2025 Jonas Kruckenberg
2//
3// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
4// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
5// http://opensource.org/licenses/MIT>, at your option. This file may not be
6// copied, modified, or distributed except according to those terms.
7
8use crate::mem::bootstrap_alloc::BootstrapAllocator;
9use crate::{INITIAL_HEAP_SIZE_PAGES, arch};
10use core::alloc::Layout;
11use core::range::Range;
12use loader_api::BootInfo;
13use talc::{ErrOnOom, Span, Talc, Talck};
14
15#[global_allocator]
16static KERNEL_ALLOCATOR: Talck<spin::Mutex<()>, ErrOnOom> = Talc::new(ErrOnOom).lock();
17
18pub fn init(boot_alloc: &mut BootstrapAllocator, boot_info: &BootInfo) {
19 let layout =
20 Layout::from_size_align(INITIAL_HEAP_SIZE_PAGES * arch::PAGE_SIZE, arch::PAGE_SIZE)
21 .unwrap();
22
23 let phys = boot_alloc.allocate_contiguous(layout).unwrap();
24
25 let virt = {
26 let start = boot_info
27 .physical_address_offset
28 .checked_add(phys.get())
29 .unwrap();
30
31 Range::from(start..start.checked_add(layout.size()).unwrap())
32 };
33 tracing::debug!("Kernel Heap: {virt:#x?}");
34
35 let mut alloc = KERNEL_ALLOCATOR.lock();
36 let span = Span::from_base_size(
37 virt.start as *mut u8,
38 virt.end.checked_sub(virt.start).unwrap(),
39 );
40
41 // Safety: just allocated the memory region
42 unsafe {
43 let old_heap = alloc.claim(span).unwrap();
44 alloc.extend(old_heap, span);
45 }
46}