Initial commit.

examples/allocator.rs

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+//! How to use the heap and a dynamic memory allocator
+//!
+//! This example depends on the embedded-alloc crate so you'll have to add it to your Cargo.toml:
+//!
+//! ``` text
+//! # or edit the Cargo.toml file manually
+//! $ cargo add embedded-alloc
+//! ```
+//!
+//! ---
+
+#![no_main]
+#![no_std]
+
+extern crate alloc;
+use panic_halt as _;
+
+use self::alloc::vec;
+use core::ptr::addr_of_mut;
+
+// Linked-List First Fit Heap allocator (feature = "llff")
+use embedded_alloc::LlffHeap as Heap;
+// Two-Level Segregated Fit Heap allocator (feature = "tlsf")
+// use embedded_alloc::TlsfHeap as Heap;
+use cortex_m_rt::entry;
+use cortex_m_semihosting::{hprintln, debug};
+
+// this is the allocator the application will use
+#[global_allocator]
+static HEAP: Heap = Heap::empty();
+
+#[entry]
+fn main() -> ! {
+    // Initialize the allocator BEFORE you use it
+    {
+        use core::mem::MaybeUninit;
+        const HEAP_SIZE: usize = 1024;
+        static mut HEAP_MEM: [MaybeUninit<u8>; HEAP_SIZE] = [MaybeUninit::uninit(); HEAP_SIZE];
+        unsafe { HEAP.init(addr_of_mut!(HEAP_MEM) as usize, HEAP_SIZE) }
+    }
+
+    // Growable array allocated on the heap
+    let xs = vec![0, 1, 2];
+
+    hprintln!("{:?}", xs);
+
+    // exit QEMU
+    // NOTE do not run this on hardware; it can corrupt OpenOCD state
+    debug::exit(debug::EXIT_SUCCESS);
+
+    loop {}
+}