59 lines
1.7 KiB
Rust
59 lines
1.7 KiB
Rust
|
use alloc::alloc::{GlobalAlloc, Layout};
|
||
|
|
use core::ptr::null_mut;
|
||
|
|
use polling_serial::serial_println;
|
||
|
|
use x86_64::instructions::bochs_breakpoint;
|
||
|
|
use x86_64::structures::paging::mapper::MapToError::PageAlreadyMapped;
|
||
|
|
use x86_64::{
|
||
|
|
structures::paging::{
|
||
|
|
mapper::MapToError, FrameAllocator, Mapper, Page, PageTableFlags, Size4KiB,
|
||
|
|
},
|
||
|
|
VirtAddr,
|
||
|
|
};
|
||
|
|
|
||
|
|
pub const HEAP_START: usize = 0x4444_4444_0000;
|
||
|
|
pub const HEAP_SIZE: usize = 0x1 << 20; // 1MB Heap
|
||
|
|
|
||
|
|
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 heap_end = heap_start + HEAP_SIZE as u64 - 1u64;
|
||
|
|
let heap_start_page = Page::containing_address(heap_start);
|
||
|
|
let heap_end_page = Page::containing_address(heap_end);
|
||
|
|
Page::range_inclusive(heap_start_page, heap_end_page)
|
||
|
|
};
|
||
|
|
|
||
|
|
let mut i = 0;
|
||
|
|
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() };
|
||
|
|
if i == 0 {
|
||
|
|
serial_println!("Mapped {:?} at {:?}", page, frame);
|
||
|
|
}
|
||
|
|
i = i + 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
unsafe {
|
||
|
|
super::ALLOCATOR.lock().init(HEAP_START, HEAP_SIZE);
|
||
|
|
}
|
||
|
|
|
||
|
|
Ok(())
|
||
|
|
}
|