diff --git a/vmbase/src/heap.rs b/vmbase/src/heap.rs
new file mode 100644
index 0000000..a28a02c
--- /dev/null
+++ b/vmbase/src/heap.rs
@@ -0,0 +1,152 @@
+// Copyright 2022, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Heap implementation.
+
+use alloc::alloc::alloc;
+use alloc::alloc::Layout;
+use alloc::boxed::Box;
+
+use core::alloc::GlobalAlloc as _;
+use core::ffi::c_void;
+use core::mem;
+use core::num::NonZeroUsize;
+use core::ptr;
+use core::ptr::NonNull;
+
+use buddy_system_allocator::LockedHeap;
+
+/// Configures the size of the global allocator.
+#[macro_export]
+macro_rules! configure_global_allocator_size {
+    ($len:expr) => {
+        static mut __HEAP_ARRAY: [u8; $len] = [0; $len];
+        #[export_name = "HEAP"]
+        // SAFETY - HEAP will only be accessed once as mut, from init().
+        static mut __HEAP: &'static mut [u8] = unsafe { &mut __HEAP_ARRAY };
+    };
+}
+
+extern "Rust" {
+    /// Slice used by the global allocator, configured using configure_global_allocator_size!().
+    static mut HEAP: &'static mut [u8];
+}
+
+#[global_allocator]
+static HEAP_ALLOCATOR: LockedHeap<32> = LockedHeap::<32>::new();
+
+/// Initialize the global allocator.
+///
+/// # Safety
+///
+/// Must be called no more than once.
+pub unsafe fn init() {
+    // SAFETY: Nothing else accesses this memory, and we hand it over to the heap to manage and
+    // never touch it again. The heap is locked, so there cannot be any races.
+    let (start, size) = unsafe { (HEAP.as_mut_ptr() as usize, HEAP.len()) };
+
+    let mut heap = HEAP_ALLOCATOR.lock();
+    // SAFETY: We are supplying a valid memory range, and we only do this once.
+    unsafe { heap.init(start, size) };
+}
+
+/// Allocate an aligned but uninitialized slice of heap.
+pub fn aligned_boxed_slice(size: usize, align: usize) -> Option<Box<[u8]>> {
+    let size = NonZeroUsize::new(size)?.get();
+    let layout = Layout::from_size_align(size, align).ok()?;
+    // SAFETY - We verify that `size` and the returned `ptr` are non-null.
+    let ptr = unsafe { alloc(layout) };
+    let ptr = NonNull::new(ptr)?.as_ptr();
+    let slice_ptr = ptr::slice_from_raw_parts_mut(ptr, size);
+
+    // SAFETY - The memory was allocated using the proper layout by our global_allocator.
+    Some(unsafe { Box::from_raw(slice_ptr) })
+}
+
+#[no_mangle]
+unsafe extern "C" fn malloc(size: usize) -> *mut c_void {
+    allocate(size, false).map_or(ptr::null_mut(), |p| p.cast::<c_void>().as_ptr())
+}
+
+#[no_mangle]
+unsafe extern "C" fn calloc(nmemb: usize, size: usize) -> *mut c_void {
+    let Some(size) = nmemb.checked_mul(size) else {
+        return ptr::null_mut()
+    };
+    allocate(size, true).map_or(ptr::null_mut(), |p| p.cast::<c_void>().as_ptr())
+}
+
+#[no_mangle]
+/// SAFETY: ptr must be null or point to a currently-allocated block returned by allocate (either
+/// directly or via malloc or calloc). Note that this function is called directly from C, so we have
+/// to trust that the C code is doing the right thing; there are checks below which will catch some
+/// errors.
+unsafe extern "C" fn free(ptr: *mut c_void) {
+    let Some(ptr) = NonNull::new(ptr) else { return };
+    // SAFETY: The contents of the HEAP slice may change, but the address range never does.
+    let heap_range = unsafe { HEAP.as_ptr_range() };
+    assert!(
+        heap_range.contains(&(ptr.as_ptr() as *const u8)),
+        "free() called on a pointer that is not part of the HEAP: {ptr:?}"
+    );
+    let (ptr, size) = unsafe {
+        // SAFETY: ptr is non-null and was allocated by allocate, which prepends a correctly aligned
+        // usize.
+        let ptr = ptr.cast::<usize>().as_ptr().offset(-1);
+        (ptr, *ptr)
+    };
+    let size = NonZeroUsize::new(size).unwrap();
+    let layout = malloc_layout(size).unwrap();
+    // SAFETY: If our precondition is satisfied, then this is a valid currently-allocated block.
+    unsafe { HEAP_ALLOCATOR.dealloc(ptr as *mut u8, layout) }
+}
+
+/// Allocate a block of memory suitable to return from `malloc()` etc. Returns a valid pointer
+/// to a suitable aligned region of size bytes, optionally zeroed (and otherwise uninitialized), or
+/// None if size is 0 or allocation fails. The block can be freed by passing the returned pointer to
+/// `free()`.
+fn allocate(size: usize, zeroed: bool) -> Option<NonNull<usize>> {
+    let size = NonZeroUsize::new(size)?.checked_add(mem::size_of::<usize>())?;
+    let layout = malloc_layout(size)?;
+    // SAFETY: layout is known to have non-zero size.
+    let ptr = unsafe {
+        if zeroed {
+            HEAP_ALLOCATOR.alloc_zeroed(layout)
+        } else {
+            HEAP_ALLOCATOR.alloc(layout)
+        }
+    };
+    let ptr = NonNull::new(ptr)?.cast::<usize>().as_ptr();
+    // SAFETY: ptr points to a newly allocated block of memory which is properly aligned
+    // for a usize and is big enough to hold a usize as well as the requested number of
+    // bytes.
+    unsafe {
+        *ptr = size.get();
+        NonNull::new(ptr.offset(1))
+    }
+}
+
+fn malloc_layout(size: NonZeroUsize) -> Option<Layout> {
+    // We want at least 8 byte alignment, and we need to be able to store a usize.
+    const ALIGN: usize = const_max_size(mem::size_of::<usize>(), mem::size_of::<u64>());
+    Layout::from_size_align(size.get(), ALIGN).ok()
+}
+
+const fn const_max_size(a: usize, b: usize) -> usize {
+    if a > b {
+        a
+    } else {
+        b
+    }
+}
diff --git a/vmbase/src/lib.rs b/vmbase/src/lib.rs
index 7fc7b20..88bad8b 100644
--- a/vmbase/src/lib.rs
+++ b/vmbase/src/lib.rs
@@ -23,6 +23,7 @@
 pub mod console;
 mod entry;
 pub mod fdt;
+pub mod heap;
 mod hvc;
 pub mod layout;
 mod linker;
diff --git a/vmbase/src/memory/mod.rs b/vmbase/src/memory/mod.rs
index 6bc600d..5e78565 100644
--- a/vmbase/src/memory/mod.rs
+++ b/vmbase/src/memory/mod.rs
@@ -25,5 +25,5 @@
 pub use shared::{alloc_shared, dealloc_shared, MemoryRange, MemoryTracker, MEMORY};
 pub use util::{
     flush, flushed_zeroize, min_dcache_line_size, page_4kb_of, phys_to_virt, virt_to_phys,
-    PAGE_SIZE, SIZE_128KB, SIZE_2MB, SIZE_4KB, SIZE_4MB,
+    PAGE_SIZE, SIZE_128KB, SIZE_2MB, SIZE_4KB, SIZE_4MB, SIZE_64KB,
 };
diff --git a/vmbase/src/memory/util.rs b/vmbase/src/memory/util.rs
index 48007f3..b9ef5c9 100644
--- a/vmbase/src/memory/util.rs
+++ b/vmbase/src/memory/util.rs
@@ -22,6 +22,8 @@
 
 /// The size of a 4KB memory in bytes.
 pub const SIZE_4KB: usize = 4 << 10;
+/// The size of a 64KB memory in bytes.
+pub const SIZE_64KB: usize = 64 << 10;
 /// The size of a 128KB memory in bytes.
 pub const SIZE_128KB: usize = 128 << 10;
 /// The size of a 2MB memory in bytes.