From 4271226fc06130d30678739d4869db4fc1820fd8 Mon Sep 17 00:00:00 2001
From: Robert Walker <rgit@walker.st>
Date: Tue, 28 Dec 2021 08:33:34 +0100
Subject: [PATCH 1/2] Added and tested the usart dma example for stm32f767zi
 using a Nucleo-f767zi board.

---
 examples/stm32f7/src/bin/usart_dma.rs | 46 +++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 examples/stm32f7/src/bin/usart_dma.rs

diff --git a/examples/stm32f7/src/bin/usart_dma.rs b/examples/stm32f7/src/bin/usart_dma.rs
new file mode 100644
index 000000000..77b5050f1
--- /dev/null
+++ b/examples/stm32f7/src/bin/usart_dma.rs
@@ -0,0 +1,46 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use core::fmt::Write;
+use embassy::executor::Executor;
+use embassy::util::Forever;
+use embassy_stm32::dma::NoDma;
+use embassy_stm32::usart::{Config, Uart};
+use embassy_traits::uart::Write as _Write;
+use example_common::*;
+
+use cortex_m_rt::entry;
+use heapless::String;
+
+#[embassy::task]
+async fn main_task() {
+    let p = embassy_stm32::init(Default::default());
+
+    let config = Config::default();
+    let mut usart = Uart::new(p.UART7, p.PA8, p.PA15, p.DMA1_CH1, NoDma, config);
+
+    for n in 0u32.. {
+        let mut s: String<128> = String::new();
+        core::write!(&mut s, "Hello DMA World {}!\r\n", n).unwrap();
+
+        usart.write(s.as_bytes()).await.ok();
+
+        info!("wrote DMA");
+    }
+}
+
+static EXECUTOR: Forever<Executor> = Forever::new();
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let executor = EXECUTOR.put(Executor::new());
+
+    executor.run(|spawner| {
+        unwrap!(spawner.spawn(main_task()));
+    })
+}

From 1028b5c671bbef06ff807a765571f6ca11dbfa8e Mon Sep 17 00:00:00 2001
From: Robert Walker <rgit@walker.st>
Date: Wed, 29 Dec 2021 08:17:51 +0100
Subject: [PATCH 2/2] Review changes

---
 examples/stm32f7/src/bin/usart_dma.rs | 26 +++++---------------------
 1 file changed, 5 insertions(+), 21 deletions(-)

diff --git a/examples/stm32f7/src/bin/usart_dma.rs b/examples/stm32f7/src/bin/usart_dma.rs
index 77b5050f1..82af0bc22 100644
--- a/examples/stm32f7/src/bin/usart_dma.rs
+++ b/examples/stm32f7/src/bin/usart_dma.rs
@@ -5,20 +5,17 @@
 #[path = "../example_common.rs"]
 mod example_common;
 use core::fmt::Write;
-use embassy::executor::Executor;
-use embassy::util::Forever;
+use embassy::executor::Spawner;
 use embassy_stm32::dma::NoDma;
 use embassy_stm32::usart::{Config, Uart};
+use embassy_stm32::Peripherals;
 use embassy_traits::uart::Write as _Write;
 use example_common::*;
 
-use cortex_m_rt::entry;
 use heapless::String;
 
-#[embassy::task]
-async fn main_task() {
-    let p = embassy_stm32::init(Default::default());
-
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
     let config = Config::default();
     let mut usart = Uart::new(p.UART7, p.PA8, p.PA15, p.DMA1_CH1, NoDma, config);
 
@@ -26,21 +23,8 @@ async fn main_task() {
         let mut s: String<128> = String::new();
         core::write!(&mut s, "Hello DMA World {}!\r\n", n).unwrap();
 
-        usart.write(s.as_bytes()).await.ok();
+        unwrap!(usart.write(s.as_bytes()).await);
 
         info!("wrote DMA");
     }
 }
-
-static EXECUTOR: Forever<Executor> = Forever::new();
-
-#[entry]
-fn main() -> ! {
-    info!("Hello World!");
-
-    let executor = EXECUTOR.put(Executor::new());
-
-    executor.run(|spawner| {
-        unwrap!(spawner.spawn(main_task()));
-    })
-}