Peripheral Access Crates

svd2rust generates mostly-safe Rust wrappers for memory-mapped peripherals from CMSIS-SVD files.

#![no_main]
#![no_std]
extern crate panic_halt as _;
use cortex_m_rt::entry;
use nrf52833_pac::Peripherals;
#[entry]
fn main() -> ! {
    let p = Peripherals::take().unwrap();
    let gpio0 = p.P0;
    // Configure GPIO 0 pins 21 and 28 as push-pull outputs.
    gpio0.pin_cnf[21].write(|w| {
        w.dir().output();
        w.input().disconnect();
        w.pull().disabled();
        w.drive().s0s1();
        w.sense().disabled();
        w
    });
    gpio0.pin_cnf[28].write(|w| {
        w.dir().output();
        w.input().disconnect();
        w.pull().disabled();
        w.drive().s0s1();
        w.sense().disabled();
        w
    });
    // Set pin 28 low and pin 21 high to turn the LED on.
    gpio0.outclr.write(|w| w.pin28().clear());
    gpio0.outset.write(|w| w.pin21().set());
    loop {}
}

• SVD (System View Description) files are XML files typically provided by silicon vendors which describe the memory map of the device.
  • They are organised by peripheral, register, field and value, with names, descriptions, addresses and so on.
  • SVD files are often buggy and incomplete, so there are various projects which patch the mistakes, add missing details, and publish the generated crates.
• cortex-m-rt provides the vector table, among other things.
• If you cargo install cargo-binutils then you can run cargo objdump --bin pac -- -d --no-show-raw-insn to see the resulting binary.

Run the example with:

cargo embed --bin pac