Update crates and adapt example code

examples/allocator.rs

@@ -1,15 +1,14 @@
 //! How to use the heap and a dynamic memory allocator
 //!
-//! This example depends on the alloc-cortex-m crate so you'll have to add it to your Cargo.toml:
+//! 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 alloc-cortex-m
+//! $ cargo add embedded-alloc
 //! ```
 //!
 //! ---
 
-#![feature(alloc_error_handler)]
 #![no_main]
 #![no_std]
 
@@ -17,28 +16,33 @@ extern crate alloc;
 use panic_halt as _;
 
 use self::alloc::vec;
-use core::alloc::Layout;
+use core::ptr::addr_of_mut;
 
-use alloc_cortex_m::CortexMHeap;
-use cortex_m::asm;
+// 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 ALLOCATOR: CortexMHeap = CortexMHeap::empty();
-
-const HEAP_SIZE: usize = 1024; // in bytes
+static HEAP: Heap = Heap::empty();
 
 #[entry]
 fn main() -> ! {
     // Initialize the allocator BEFORE you use it
-    unsafe { ALLOCATOR.init(cortex_m_rt::heap_start() as usize, HEAP_SIZE) }
+    {
+        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).unwrap();
+    hprintln!("{:?}", xs);
 
     // exit QEMU
     // NOTE do not run this on hardware; it can corrupt OpenOCD state
@@ -46,11 +50,3 @@ fn main() -> ! {
 
     loop {}
 }
-
-// define what happens in an Out Of Memory (OOM) condition
-#[alloc_error_handler]
-fn alloc_error(_layout: Layout) -> ! {
-    asm::bkpt();
-
-    loop {}
-}

examples/crash.rs

@@ -97,8 +97,8 @@ fn main() -> ! {
     loop {}
 }
 
-#[exception]
-fn HardFault(ef: &ExceptionFrame) -> ! {
+#[exception(trampoline = true)]
+unsafe fn HardFault(ef: &ExceptionFrame) -> ! {
     if let Ok(mut hstdout) = hio::hstdout() {
         writeln!(hstdout, "{:#?}", ef).ok();
     }

examples/device.rs

@@ -58,5 +58,5 @@ fn main() -> ! {
 
 #[interrupt]
 fn EXTI0() {
-    hprint!(".").unwrap();
+    hprint!(".");
 }

examples/exception.rs

@@ -33,5 +33,5 @@ fn main() -> ! {
 
 #[exception]
 fn SysTick() {
-    hprint!(".").unwrap();
+    hprint!(".");
 }

examples/hello.rs

@@ -10,7 +10,7 @@ use cortex_m_semihosting::{debug, hprintln};
 
 #[entry]
 fn main() -> ! {
-    hprintln!("Hello, world!").unwrap();
+    hprintln!("Hello, world!");
 
     // exit QEMU
     // NOTE do not run this on hardware; it can corrupt OpenOCD state