40 lines
1.5 KiB
Rust
40 lines
1.5 KiB
Rust
use alloc::alloc::GlobalAlloc;
|
|
use core::alloc::Layout;
|
|
use uefi::prelude::{Boot, SystemTable};
|
|
use uefi::table::boot::{AllocateType, MemoryType};
|
|
|
|
/// **This allocator only supports page-level granularity.**
|
|
/// Be careful not to use it for small allocations.
|
|
/// In particular, it should only be used to allocate data structures
|
|
/// for the purpose of setting up another, better allocator.
|
|
pub struct UefiAllocator {
|
|
// We must directly store an owned system table because:
|
|
// 1. It is impossible to take ownership of ST boot services, and
|
|
// 2. we cannot store a reference to *anything* here
|
|
// because the global allocator has to be static even if we know it's really not.
|
|
st: SystemTable<Boot>,
|
|
}
|
|
|
|
impl UefiAllocator {
|
|
pub fn new(st: SystemTable<Boot>) -> UefiAllocator {
|
|
UefiAllocator { st: st }
|
|
}
|
|
}
|
|
|
|
const PAGE_SIZE: usize = 4096;
|
|
|
|
unsafe impl GlobalAlloc for UefiAllocator {
|
|
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
|
|
self.st.boot_services()
|
|
.allocate_pages(AllocateType::AnyPages, MemoryType::LOADER_DATA,
|
|
num_integer::div_ceil(layout.size(), PAGE_SIZE))
|
|
.expect("Failed to allocate memory!").unwrap()
|
|
as *mut u8
|
|
}
|
|
|
|
unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
|
|
self.st.boot_services().free_pages(ptr as u64, num_integer::div_ceil(layout.size(), PAGE_SIZE))
|
|
.expect("Failed to free memory!").unwrap();
|
|
}
|
|
}
|