* Fix two timing issues in delays.rs
These changes correct the implementations of delays::SysTmr::wait_msec_st
and delays::wait_msec to behave correctly and consistently with one another.
* Port delay fix from 09_delays to 0B_exception_levels
I believe this covers all copies of this bug in the codebase.
* Rebuild tutorial kernels with delay fixes
The new target is not automatically using PIC.
Need some linker script corrections for errors that were hiding
previously, so that we don't accidentally generate alignment
exceptions on bss size variables that cause the target to fail.
We have a generic target for writing bare-metal code
for 64-bit ARM architectures in upstream Rust now.
Use it to get rid of the fully custom target spec.
\o/
We now have the same API for MMIO and CPU registers.
Makes the code more concise, inntuitive, and improves readability.
https://crates.io/crates/register
