56 lines
1.5 KiB
Rust
56 lines
1.5 KiB
Rust
|
use alloc::alloc::{GlobalAlloc, Layout};
|
||
|
use core::ptr::null_mut;
|
||
|
use x86_64:: {
|
||
|
structures::paging:: {
|
||
|
FrameAllocator,
|
||
|
mapper::MapToError,
|
||
|
Mapper,
|
||
|
Page,
|
||
|
PageTableFlags,
|
||
|
Size4KiB,
|
||
|
},
|
||
|
VirtAddr,
|
||
|
};
|
||
|
|
||
|
pub const HEAP_START: usize = 0x_4444_4444_0000;
|
||
|
pub const HEAP_SIZE: usize = 100 * 1024; // 100 KiB
|
||
|
|
||
|
pub struct Dummy;
|
||
|
|
||
|
unsafe impl GlobalAlloc for Dummy {
|
||
|
unsafe fn alloc(&self, _layout: Layout) -> *mut u8 {
|
||
|
null_mut()
|
||
|
}
|
||
|
|
||
|
unsafe fn dealloc(&self, _ptr: *mut u8, _layout: Layout) {
|
||
|
panic!("dealloc should never be called")
|
||
|
}
|
||
|
}
|
||
|
|
||
|
pub fn init_heap(
|
||
|
mapper: &mut impl Mapper<Size4KiB>,
|
||
|
frame_allocator: &mut impl FrameAllocator<Size4KiB>,
|
||
|
) -> Result<(), MapToError> {
|
||
|
let page_range = {
|
||
|
let heap_start = VirtAddr::new(HEAP_START as u64);
|
||
|
let head_end = heap_start + HEAP_SIZE - 1u64;
|
||
|
let heap_start_page = Page::containing_address(heap_start);
|
||
|
let heap_end_page = Page::containing_address(head_end);
|
||
|
Page::range_inclusive(heap_start_page, heap_end_page)
|
||
|
};
|
||
|
|
||
|
for page in page_range {
|
||
|
let frame = frame_allocator
|
||
|
.allocate_frame()
|
||
|
.ok_or(MapToError::FrameAllocationFailed)?;
|
||
|
|
||
|
let flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE;
|
||
|
unsafe { mapper.map_to(page, frame, flags, frame_allocator)?.flush() };
|
||
|
}
|
||
|
|
||
|
unsafe {
|
||
|
super::ALLOCATOR.lock().init(HEAP_START, HEAP_SIZE);
|
||
|
}
|
||
|
|
||
|
Ok(())
|
||
|
}
|