Set up peripherals.

Need to amend HAL to support SPI Peripheral mode (it is Controller
only at the moment).

Author: thejpster

build.rs

@@ -1,6 +1,6 @@
 /// This is the build-script for the Neotron BMC.
 ///
-/// It just copies the memory.x file somewhere Cargo can fine it.
+/// It just copies the memory.x file somewhere Cargo can find it, then generates a version header.
 use std::env;
 use std::fs::File;
 use std::io::Write;
@@ -15,4 +15,14 @@ fn main() {
         .unwrap();
     println!("cargo:rustc-link-search={}", out.display());
     println!("cargo:rerun-if-changed=memory.x");
+
+
+    let version_output = std::process::Command::new("git")
+    .current_dir(env::var_os("CARGO_MANIFEST_DIR").unwrap())
+    .args(&["describe", "--tags", "--all", "--dirty"])
+    .output()
+    .expect("running git-describe");
+    assert!(version_output.status.success());
+
+    std::fs::write(out.join("version.txt"), version_output.stdout).expect("writing version file");
 }

src/lib.rs

@@ -4,8 +4,7 @@ use core::sync::atomic::{AtomicUsize, Ordering};
 
 use defmt_rtt as _; // global logger
 use stm32f0xx_hal as _; // memory layout
-
-use panic_probe as _;
+use panic_probe as _; // panic handler
 
 // same panicking *behavior* as `panic-probe` but doesn't print a panic message
 // this prevents the panic message being printed *twice* when `defmt::panic` is invoked

src/main.rs

@@ -1,11 +1,49 @@
 #![no_main]
 #![no_std]
 
-use neotron_bmc as _; // global logger + panicking-behavior + memory layout
+use neotron_bmc as _;
+
+use stm32f0xx_hal as hal;
+use hal::{prelude::*, pac, spi, i2c, serial};
+
+static VERSION: &'static str = include_str!(concat!(env!("OUT_DIR"), "/version.txt"));
+
+const MODE_0: spi::Mode = spi::Mode {
+    polarity: spi::Polarity::IdleLow,
+    phase: spi::Phase::CaptureOnFirstTransition,
+};
 
 #[cortex_m_rt::entry]
 fn main() -> ! {
-    defmt::info!("Hello, world!");
+    defmt::info!("Neotron BMC version {:?} booting", VERSION);
+
+    let p = pac::Peripherals::take().unwrap();
+
+    let mut flash = p.FLASH;
+    let mut rcc = p.RCC.configure().freeze(&mut flash);
+
+    let gpioa = p.GPIOA.split(&mut rcc);
+    let gpiob = p.GPIOB.split(&mut rcc);
+
+    let (sck, miso, mosi, scl, sda, tx, rx) = cortex_m::interrupt::free(move |cs| {
+        (
+            // SPI pins
+            gpioa.pa5.into_alternate_af0(cs),
+            gpioa.pa6.into_alternate_af0(cs),
+            gpioa.pa7.into_alternate_af0(cs),
+            // I²C pins
+            gpioa.pa9.into_alternate_af4(cs),
+            gpioa.pa10.into_alternate_af4(cs),
+            // USART pins
+            gpiob.pb6.into_alternate_af0(cs),
+            gpiob.pb7.into_alternate_af0(cs),
+        )
+    });
+
+    // Configure SPI with 1MHz rate
+    let spi = spi::Spi::spi1(p.SPI1, (sck, miso, mosi), MODE_0, 1.mhz(), &mut rcc);
+    let serial = serial::Serial::usart1(p.USART1, (tx, rx), 115_200.bps(), &mut rcc);
+    let i2c = i2c::I2c::i2c1(p.I2C1, (scl, sda), 100.khz(), &mut rcc);
 
     neotron_bmc::exit()
 }