Tock V2 port - rebased and updated (#620)

* Changes from #580

* fixes USB cancel panic

* style fixes

* Update src/env/tock/storage.rs

Co-authored-by: Zach Halvorsen <zhalvorsen@google.com>

---------

Co-authored-by: Zach Halvorsen <zhalvorsen@google.com>

bootloader/src/crypto_cell.rs

@@ -26,6 +26,7 @@ use super::static_ref::StaticRef;
 use core::cell::Cell;
 #[cfg(debug_assertions)]
 use rtt_target::rprintln;
+use tock_registers::interfaces::{Readable, Writeable};
 
 const SHA256_INIT_VALUE: [u32; 8] = [
     0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19,

bootloader/src/static_ref.rs

@@ -40,7 +40,7 @@ impl<T> Copy for StaticRef<T> {}
 
 impl<T> Deref for StaticRef<T> {
     type Target = T;
-    fn deref(&self) -> &'static T {
+    fn deref(&self) -> &T {
         unsafe { &*self.ptr }
     }
 }