Implement signature module

Can be used to read the flash size and device UID

Author: JanekGraff

src/lib.rs

@@ -58,6 +58,8 @@ pub mod spi;
 pub mod time;
 #[cfg(feature = "device-selected")]
 pub mod timers;
+#[cfg(feature = "device-selected")]
+pub mod signature;
 #[cfg(any(
     feature = "stm32f031",
     feature = "stm32f051",

src/signature.rs

@@ -0,0 +1,80 @@
+//! Device electronic signature
+//!
+//! (stored in flash memory)
+
+use core::str::from_utf8_unchecked;
+
+/// This is the test voltage in millivolts of the calibration done at the factory
+pub const VDDA_CALIB: u32 = 3300;
+
+macro_rules! define_ptr_type {
+    ($name: ident, $ptr: expr) => {
+        impl $name {
+            fn ptr() -> *const Self {
+                $ptr as *const _
+            }
+
+            /// Returns a wrapped reference to the value in flash memory
+            pub fn get() -> &'static Self {
+                unsafe { &*Self::ptr() }
+            }
+        }
+    };
+}
+
+// f030 and f070 don't have a UID in ROM
+#[cfg(not(any(feature = "stm32f030", feature = "stm32f070")))]
+#[derive(Hash, Debug)]
+#[repr(C)]
+pub struct Uid {
+    x: u16,
+    y: u16,
+    waf_lot: [u8; 8],
+}
+#[cfg(not(any(feature = "stm32f030", feature = "stm32f070")))]
+define_ptr_type!(Uid, 0x1FFF_F7AC);
+
+/// Device UID from ROM. See the [reference manual](https://www.st.com/content/ccc/resource/technical/document/reference_manual/c2/f8/8a/f2/18/e6/43/96/DM00031936.pdf/files/DM00031936.pdf/jcr:content/translations/en.DM00031936.pdf#%5B%7B%22num%22%3A1575%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C67%2C755%2Cnull%5D) for more info.
+#[cfg(not(any(feature = "stm32f030", feature = "stm32f070")))]
+impl Uid {
+    /// X coordinate on wafer
+    pub fn x(&self) -> u16 {
+        self.x
+    }
+
+    /// Y coordinate on wafer
+    pub fn y(&self) -> u16 {
+        self.y
+    }
+
+    /// Wafer number
+    pub fn waf_num(&self) -> u8 {
+        self.waf_lot[0]
+    }
+
+    /// Lot number
+    pub fn lot_num(&self) -> &str {
+        unsafe { from_utf8_unchecked(&self.waf_lot[1..]) }
+    }
+}
+
+/// Size of integrated flash
+#[derive(Debug)]
+#[repr(C)]
+pub struct FlashSize(u16);
+#[cfg(not(any(feature = "stm32f030", feature = "stm32f070")))]
+define_ptr_type!(FlashSize, 0x1FFF_F7CC);
+#[cfg(any(feature = "stm32f030", feature = "stm32f070"))]
+define_ptr_type!(FlashSize, 0x1FFF_0000);
+
+impl FlashSize {
+    /// Read flash size in kilobytes
+    pub fn kilo_bytes(&self) -> u16 {
+        self.0
+    }
+
+    /// Read flash size in bytes
+    pub fn bytes(&self) -> usize {
+        usize::from(self.kilo_bytes()) * 1024
+    }
+}