How long does it take to build a peripheral access crate (PAC) for different i.MX RT MCUs?
Let's find out!
[Here](https://www.mciantyre.dev/2025/06/30/imxrt-pac-shootout.html) are my measurements.

We'll use three different PAC representations:

1. the classic [svd2rust] PAC.
2. the [chiptool] PAC, preferred by [embassy].
3. the register access layer (RAL) design, first pioneered by [stm32ral] and
  later adopted by [imxrt-ral].

[svd2rust]: https://github.com/rust-embedded/svd2rust
[stm32ral]: https://github.com/adamgreig/stm32ral
[imxrt-ral]: https://github.com/imxrt-rs/imxrt-ral
[embassy]: https://github.com/embassy-rs
[chiptool]: https://github.com/embassy-rs/chiptool

With each of these, we'll build PACs for four different i.MX RT MCUs:

1. iMXRT1011
2. iMXRT1062
3. iMXRT1176 (Cortex-M7 only)
4. iMXRT1189 (Cortex-M33 only)

We'll clean-build all PACs in release mode, targeting the best architecture profile for each MCU.
Note that this also includes the time to build PAC dependencies.
We'll trust Cargo's reporting of how long it takes.

## Try it out

Clone this repository along with all of its submodules.

```
git clone --recurse-submodules https://git.mciantyre.dev/imxrt-pac-shootout
```

Install the Rust targets we're using to build PACs:

```
rustup target add thumbv7em-none-eabihf thumbv8m.main-none-eabihf
```

The rest of these commands should automatically build the tools and intermediates
needed for codegen.

### imxrt-ral

This one is the simplest: clean-build the package for each MCU.

```
make -j imxrt-ral.shootout
```

### imxrt-svd2rust

Generate four PACs using `svd2rust`, supplying the same patched SVDs used by imxrt-ral.
Separate each PAC's modules with `form`, and format them with `rustfmt`.
Then, build all four PACs.

```
make -j imxrt-svd2rust.shootout
```

### imxrt-chiptool

Generate four PACs using `chiptool`, supplying the same patched SVDs used by imxrt-ral.
Use a transform file that's equivalent to what imxrt-ral uses.

Separate each PAC's modules with `form`, and format them with `rustfmt`.
Then, build all four PACs.

```
make -j imxrt-chiptool.shootout
```