Add F4 flash driver

examples/stm32f4/Cargo.toml

@@ -19,6 +19,7 @@ panic-probe = { version = "0.3", features = ["print-defmt"] }
 futures = { version = "0.3.17", default-features = false, features = ["async-await"] }
 heapless = { version = "0.7.5", default-features = false }
 nb = "1.0.0"
+embedded-storage = "0.3.0"
 
 usb-device = "0.2"
 usbd-serial = "0.1.1"

examples/stm32f4/src/bin/flash.rs

@@ -0,0 +1,57 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::{info, unwrap};
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy_stm32::flash::Flash;
+use embassy_stm32::Peripherals;
+use embedded_storage::nor_flash::{NorFlash, ReadNorFlash};
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Hello Flash!");
+
+    const ADDR: u32 = 0x10_0000;
+
+    // wait a bit before accessing the flash
+    Timer::after(Duration::from_millis(300)).await;
+
+    let mut f = Flash::unlock(p.FLASH);
+
+    info!("Reading...");
+    let mut buf = [0u8; 32];
+    unwrap!(f.read(ADDR, &mut buf));
+    info!("Read: {=[u8]:x}", buf);
+
+    info!("Erasing...");
+    unwrap!(f.erase(ADDR, ADDR + 128 * 1024));
+
+    info!("Reading...");
+    let mut buf = [0u8; 32];
+    unwrap!(f.read(ADDR, &mut buf));
+    info!("Read after erase: {=[u8]:x}", buf);
+
+    info!("Writing...");
+    unwrap!(f.write(
+        ADDR,
+        &[
+            1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
+            30, 31, 32
+        ]
+    ));
+
+    info!("Reading...");
+    let mut buf = [0u8; 32];
+    unwrap!(f.read(ADDR, &mut buf));
+    info!("Read: {=[u8]:x}", buf);
+    assert_eq!(
+        &buf[..],
+        &[
+            1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
+            30, 31, 32
+        ]
+    );
+}