Use linked list allocator

alloc/hole_list_allocator/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+authors = ["Philipp Oppermann <dev@phil-opp.com>"]
+name = "hole_list_allocator"
+version = "0.1.0"
+
+[dependencies]
+linked_list_allocator = "0.2.0"
+spin = "0.3.5"
+
+[dependencies.lazy_static]
+version = "0.2.1"
+features = ["spin_no_std"]

alloc/hole_list_allocator/src/lib.rs

@@ -0,0 +1,59 @@
+#![feature(allocator)]
+#![feature(const_fn)]
+
+#![allocator]
+#![no_std]
+
+use spin::Mutex;
+use linked_list_allocator::Heap;
+
+extern crate spin;
+extern crate linked_list_allocator;
+#[macro_use]
+extern crate lazy_static;
+
+pub const HEAP_START: usize = 0x1_0000_0000; // Put at end of 4GB
+pub const HEAP_SIZE: usize = 16 * 1024 * 1024; // 16 MB
+
+lazy_static! {
+    static ref HEAP: Mutex<Heap> = Mutex::new(unsafe {
+        Heap::new(HEAP_START, HEAP_SIZE)
+    });
+}
+
+#[no_mangle]
+pub extern fn __rust_allocate(size: usize, align: usize) -> *mut u8 {
+    HEAP.lock().allocate_first_fit(size, align).expect("out of memory")
+}
+
+#[no_mangle]
+pub extern fn __rust_deallocate(ptr: *mut u8, size: usize, align: usize) {
+    unsafe { HEAP.lock().deallocate(ptr, size, align) };
+}
+
+#[no_mangle]
+pub extern fn __rust_usable_size(size: usize, _align: usize) -> usize {
+    size
+}
+
+#[no_mangle]
+pub extern fn __rust_reallocate_inplace(_ptr: *mut u8, size: usize,
+    _new_size: usize, _align: usize) -> usize
+{
+    size
+}
+
+#[no_mangle]
+pub extern fn __rust_reallocate(ptr: *mut u8, size: usize, new_size: usize,
+                                align: usize) -> *mut u8 {
+    use core::{ptr, cmp};
+
+    // from: https://github.com/rust-lang/rust/blob/
+    //     c66d2380a810c9a2b3dbb4f93a830b101ee49cc2/
+    //     src/liballoc_system/lib.rs#L98-L101
+
+    let new_ptr = __rust_allocate(new_size, align);
+    unsafe { ptr::copy(ptr, new_ptr, cmp::min(size, new_size)) };
+    __rust_deallocate(ptr, size, align);
+    new_ptr
+}