add Exception

1 files changed, 47 insertions, 0 deletions

diff --git a/src/exception.rs b/src/exception.rs
new file mode 100644
index 0000000..7046080
--- /dev/null
+++ b/src/exception.rs
@@ -0,0 +1,47 @@
+/// Kind of exception
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum Exception {
+    /// i.e. currently not servicing an exception
+    ThreadMode,
+    /// Non-maskable interrupt.
+    Nmi,
+    /// All class of fault.
+    HardFault,
+    /// Memory management.
+    MemoryManagementFault,
+    /// Pre-fetch fault, memory access fault.
+    BusFault,
+    /// Undefined instruction or illegal state.
+    UsageFault,
+    /// System service call via SWI instruction
+    SVCall,
+    /// Pendable request for system service
+    PendSV,
+    /// System tick timer
+    Systick,
+    /// An interrupt
+    Interrupt(u8),
+    // Unreachable variant
+    #[doc(hidden)]
+    Reserved,
+}
+
+impl Exception {
+    /// Returns the kind of exception that's currently being serviced
+    pub fn current() -> Exception {
+        match ::peripheral::scb().icsr.read() as u8 {
+            0 => Exception::ThreadMode,
+            2 => Exception::Nmi,
+            3 => Exception::HardFault,
+            4 => Exception::MemoryManagementFault,
+            5 => Exception::BusFault,
+            6 => Exception::UsageFault,
+            11 => Exception::SVCall,
+            14 => Exception::PendSV,
+            15 => Exception::Systick,
+            n if n >= 16 => Exception::Interrupt(n - 16),
+            _ => Exception::Reserved,
+
+        }
+    }
+}