Update some speaker notes for bare metal Rust section (#2764)

Author: qwandor

src/bare-metal/aps/better-uart/driver.md

@@ -12,6 +12,7 @@ Now let's use the new `Registers` struct in our driver.
   register. The caller of `UniqueMmioPointer::new` promises that it is valid and
   unique for the given lifetime, so it can provide safe methods to read and
   write fields.
+- Note that `Uart::new` is now safe; `UniqueMmioPointer::new` is unsafe instead.
 - These MMIO accesses are generally a wrapper around `read_volatile` and
   `write_volatile`, though on aarch64 they are instead implemented in assembly
   to work around a bug where the compiler can emit instructions that prevent

src/bare-metal/useful-crates/aarch64-paging.md

@@ -25,13 +25,11 @@ idmap.activate();
 
 <details>
 
-- For now it only supports EL1, but support for other exception levels should be
-  straightforward to add.
 - This is used in Android for the [Protected VM Firmware][2].
-- There's no easy way to run this example, as it needs to run on real hardware
-  or under QEMU.
+- There's no easy way to run this example by itself, as it needs to run on real
+  hardware or under QEMU.
 
 </details>
 
 [1]: https://crates.io/crates/aarch64-paging
-[2]: https://cs.android.com/android/platform/superproject/+/master:packages/modules/Virtualization/pvmfw/
+[2]: https://cs.android.com/android/platform/superproject/main/+/main:packages/modules/Virtualization/guest/pvmfw/