Merge pull request rp-rs#311 from Liamolucko/multicore-no-alloc

Remove the `alloc` requirement for `Core::spawn`

Author: 9names

rp2040-hal/Cargo.toml

@@ -42,7 +42,6 @@ dht-sensor = "0.2.1"
 
 [features]
 rt = ["rp2040-pac/rt"]
-alloc = []
 rom-func-cache = []
 disable-intrinsics = []
 rom-v2-intrinsics = []

rp2040-hal/examples/multicore_fifo_blink.rs

@@ -57,7 +57,7 @@ const CORE1_TASK_COMPLETE: u32 = 0xEE;
 /// the stack guard to take up the least amount of usable RAM.
 static mut CORE1_STACK: Stack<4096> = Stack::new();
 
-fn core1_task() -> ! {
+fn core1_task(sys_freq: u32) -> ! {
     let mut pac = unsafe { pac::Peripherals::steal() };
     let core = unsafe { pac::CorePeripherals::steal() };
 
@@ -70,10 +70,6 @@ fn core1_task() -> ! {
     );
 
     let mut led_pin = pins.gpio25.into_push_pull_output();
-    // The first thing core0 sends us is the system bus frequency.
-    // The systick is based on this frequency, so we need that to
-    // be accurate when sleeping via cortex_m::delay::Delay
-    let sys_freq = sio.fifo.read_blocking();
     let mut delay = cortex_m::delay::Delay::new(core.SYST, sys_freq);
     loop {
         let input = sio.fifo.read();
@@ -114,17 +110,18 @@ fn main() -> ! {
     .ok()
     .unwrap();
 
+    let sys_freq = clocks.system_clock.freq().integer();
+
     // The single-cycle I/O block controls our GPIO pins
     let mut sio = hal::sio::Sio::new(pac.SIO);
 
-    let mut mc = Multicore::new(&mut pac.PSM, &mut pac.PPB, &mut sio);
+    let mut mc = Multicore::new(&mut pac.PSM, &mut pac.PPB, &mut sio.fifo);
     let cores = mc.cores();
     let core1 = &mut cores[1];
-    let _test = core1.spawn(core1_task, unsafe { &mut CORE1_STACK.mem });
+    let _test = core1.spawn(unsafe { &mut CORE1_STACK.mem }, move || {
+        core1_task(sys_freq)
+    });
 
-    // Let core1 know how fast the system clock is running
-    let sys_freq = clocks.system_clock.freq().integer();
-    sio.fifo.write_blocking(sys_freq);
     /// How much we adjust the LED period every cycle
     const LED_PERIOD_INCREMENT: i32 = 2;
 

rp2040-hal/examples/multicore_polyblink.rs

@@ -0,0 +1,133 @@
+//! # Multicore Blinking Example
+//!
+//! This application blinks two LEDs on GPIOs 2 and 3 at different rates (3Hz
+//! and 4Hz respectively.)
+//!
+//! See the `Cargo.toml` file for Copyright and licence details.
+
+#![no_std]
+#![no_main]
+
+use cortex_m::delay::Delay;
+// The macro for our start-up function
+use cortex_m_rt::entry;
+
+use embedded_time::fixed_point::FixedPoint;
+use hal::clocks::Clock;
+use hal::gpio::Pins;
+use hal::multicore::{Multicore, Stack};
+use hal::sio::Sio;
+// Ensure we halt the program on panic (if we don't mention this crate it won't
+// be linked)
+use panic_halt as _;
+
+// Alias for our HAL crate
+use rp2040_hal as hal;
+
+// A shorter alias for the Peripheral Access Crate, which provides low-level
+// register access
+use hal::pac;
+
+// Some traits we need
+use embedded_hal::digital::v2::ToggleableOutputPin;
+
+/// The linker will place this boot block at the start of our program image. We
+/// need this to help the ROM bootloader get our code up and running.
+#[link_section = ".boot2"]
+#[used]
+pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER_W25Q080;
+
+/// External high-speed crystal on the Raspberry Pi Pico board is 12 MHz. Adjust
+/// if your board has a different frequency
+const XTAL_FREQ_HZ: u32 = 12_000_000u32;
+
+/// The frequency at which core 0 will blink its LED (Hz).
+const CORE0_FREQ: u32 = 3;
+/// The frequency at which core 1 will blink its LED (Hz).
+const CORE1_FREQ: u32 = 4;
+/// The delay between each toggle of core 0's LED (us).
+const CORE0_DELAY: u32 = 1_000_000 / CORE0_FREQ;
+/// The delay between each toggle of core 1's LED (us).
+const CORE1_DELAY: u32 = 1_000_000 / CORE1_FREQ;
+
+/// Stack for core 1
+///
+/// Core 0 gets its stack via the normal route - any memory not used by static
+/// values is reserved for stack and initialised by cortex-m-rt.
+/// To get the same for Core 1, we would need to compile everything seperately
+/// and modify the linker file for both programs, and that's quite annoying.
+/// So instead, core1.spawn takes a [usize] which gets used for the stack.
+/// NOTE: We use the `Stack` struct here to ensure that it has 32-byte
+/// alignment, which allows the stack guard to take up the least amount of
+/// usable RAM.
+static mut CORE1_STACK: Stack<4096> = Stack::new();
+
+/// Entry point to our bare-metal application.
+///
+/// The `#[entry]` macro ensures the Cortex-M start-up code calls this function
+/// as soon as all global variables are initialised.
+#[entry]
+fn main() -> ! {
+    // Grab our singleton objects
+    let mut pac = pac::Peripherals::take().unwrap();
+    let core = pac::CorePeripherals::take().unwrap();
+
+    // Set up the watchdog driver - needed by the clock setup code
+    let mut watchdog = hal::watchdog::Watchdog::new(pac.WATCHDOG);
+
+    // Configure the clocks
+    let clocks = hal::clocks::init_clocks_and_plls(
+        XTAL_FREQ_HZ,
+        pac.XOSC,
+        pac.CLOCKS,
+        pac.PLL_SYS,
+        pac.PLL_USB,
+        &mut pac.RESETS,
+        &mut watchdog,
+    )
+    .ok()
+    .unwrap();
+
+    // Set up the GPIO pins
+    let mut sio = Sio::new(pac.SIO);
+    let pins = Pins::new(
+        pac.IO_BANK0,
+        pac.PADS_BANK0,
+        sio.gpio_bank0,
+        &mut pac.RESETS,
+    );
+    let mut led1 = pins.gpio2.into_push_pull_output();
+    let mut led2 = pins.gpio3.into_push_pull_output();
+
+    // Set up the delay for the first core.
+    let sys_freq = clocks.system_clock.freq().integer();
+    let mut delay = Delay::new(core.SYST, sys_freq);
+
+    // Start up the second core to blink the second LED
+    let mut mc = Multicore::new(&mut pac.PSM, &mut pac.PPB, &mut sio.fifo);
+    let cores = mc.cores();
+    let core1 = &mut cores[1];
+    core1
+        .spawn(unsafe { &mut CORE1_STACK.mem }, move || {
+            // Get the second core's copy of the `CorePeripherals`, which are per-core.
+            // Unfortunately, `cortex-m` doesn't support this properly right now,
+            // so we have to use `steal`.
+            let core = unsafe { pac::CorePeripherals::steal() };
+            // Set up the delay for the second core.
+            let mut delay = Delay::new(core.SYST, sys_freq);
+            // Blink the second LED.
+            loop {
+                led2.toggle().unwrap();
+                delay.delay_us(CORE1_DELAY)
+            }
+        })
+        .unwrap();
+
+    // Blink the first LED.
+    loop {
+        led1.toggle().unwrap();
+        delay.delay_us(CORE0_DELAY)
+    }
+}
+
+// End of file