✨ Enable global allocator

src/main.rs

@@ -2,16 +2,18 @@
 #![no_main]
 #![no_std]
 
+extern crate alloc;
+
 use core::cell::RefCell;
 use core::convert::Infallible;
 
 use defmt_rtt as _;
 use panic_probe as _;
-
 use stm32f3xx_hal as hal;
 
 use cortex_m::interrupt::Mutex;
 use cortex_m_rt::entry;
+use embedded_alloc::LlffHeap;
 use embedded_hal::digital::v2::{OutputPin, ToggleableOutputPin};
 use embedded_hal::timer::CountDown;
 use embedded_time::duration::Extensions as DurationExt;
@@ -23,6 +25,9 @@ use hal::pac::{NVIC, TIM2};
 use hal::rcc::RccExt;
 use hal::timer::{Event as TimerEvent, Timer};
 
+#[global_allocator]
+static HEAP: LlffHeap = LlffHeap::empty();
+
 type LedType = &'static mut (dyn ToggleableOutputPin<Error = Infallible> + Send + Sync);
 static LED: Mutex<RefCell<Option<LedType>>> = Mutex::new(RefCell::new(None));
 
@@ -31,6 +36,18 @@ static TIMER: Mutex<RefCell<Option<Timer<TIM2>>>> = Mutex::new(RefCell::new(None
 #[entry]
 fn main() -> ! {
     defmt::debug!("entry");
+
+    // Initialize the allocator
+    {
+        use core::mem::MaybeUninit;
+        const HEAP_SIZE: usize = 1024;
+        static mut HEAP_MEM: [MaybeUninit<u8>; HEAP_SIZE] = [MaybeUninit::uninit(); HEAP_SIZE];
+        #[allow(unsafe_code)]
+        unsafe {
+            HEAP.init(HEAP_MEM.as_ptr() as usize, HEAP_SIZE);
+        }
+    }
+
     let dp = pac::Peripherals::take().unwrap();
 
     let mut flash = dp.FLASH.constrain();