akern-gkgoat-fork/ableos/src/allocator/aalloc.rs

74 lines
1.9 KiB
Rust

//! The allocator to be implemented by ableOS
//!
//! NOTE: All memory regions are taken from https://wiki.osdev.org/Memory_Map_(x86)
use alloc::alloc::{GlobalAlloc, Layout};
use core::{fmt::Display, ptr::null_mut};
const HEAP_START: usize = 600_000_000;
const BLOCK_SIZE: usize = 1024;
const BLOCK_COUNT: usize = 512;
#[derive(Debug, Clone, Copy)]
pub struct MemoryRegion {
_start: usize,
_end: usize,
}
#[derive(Debug, Clone, Copy)]
pub struct AAlloc {
current_region: usize,
memory_regions: [Option<MemoryRegion>; 512],
}
impl AAlloc {
pub fn add_region(&mut self, mem: MemoryRegion) {
self.memory_regions[self.current_region] = Some(mem);
self.current_region += 1;
}
pub fn intialize() {
info!("Heap Start: {}", HEAP_START);
info!("Heap Size: {}", BLOCK_SIZE * BLOCK_COUNT);
info!("Heap End: {}", HEAP_START + BLOCK_SIZE * BLOCK_COUNT);
let mut aalloc = AAlloc {
current_region: 0,
memory_regions: [None; 512],
};
aalloc.add_region(MemoryRegion {
_start: 0x00100000,
_end: 0x00EFFFFF,
});
debug!("{}", aalloc);
}
}
impl Display for AAlloc {
fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
write!(f, "AAlloc {{\n\tcurrent_region: {},\n", self.current_region)?;
for x in 0..self.current_region {
if let Some(region) = self.memory_regions[x] {
write!(f, "\tRegion {}: {:?}\n", x, region)?;
}
}
write!(f, "}}")?;
Ok(())
}
}
unsafe impl GlobalAlloc for AAlloc {
unsafe fn alloc(&self, _layout: Layout) -> *mut u8 {
println!("Allocating memory");
println!("{}", _layout.size());
println!("{}", _layout.align());
null_mut()
}
unsafe fn dealloc(&self, _ptr: *mut u8, _layout: Layout) {
panic!("dealloc should be never called")
}
}