1 files changed, 67 insertions, 0 deletions
diff --git a/crates/teensy4/src/lib.rs b/crates/teensy4/src/lib.rs
new file mode 100644
index 0000000..35afb31
--- /dev/null
+++ b/crates/teensy4/src/lib.rs
@@ -0,0 +1,67 @@
+#![no_std]
+#![feature(rustc_private)]
+extern crate fusible;
+
+use core::pin::Pin;
+
+use rust_threadx_cortex_m as _;
+use rust_threadx_stdio_imxrt_usbd as stdio;
+
+#[doc(hidden)]
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn _tx_initialize_low_level() {
+    use cortex_m::{
+        Peripherals,
+        peripheral::{scb::SystemHandler, syst::SystClkSource},
+    };
+
+    cortex_m::interrupt::disable();
+
+    unsafe {
+        let Peripherals {
+            mut SYST, mut SCB, ..
+        } = Peripherals::steal();
+
+        SCB.set_priority(SystemHandler::SysTick, 0x40);
+        SCB.set_priority(SystemHandler::PendSV, 0xff);
+        SCB.set_priority(SystemHandler::SVCall, 0xff);
+
+        SYST.set_clock_source(SystClkSource::External);
+        SYST.set_reload(100_000 / 100 - 1);
+        SYST.clear_current();
+        SYST.enable_interrupt();
+        SYST.enable_counter();
+    }
+}
+
+use fusible::thread::{StaticStack, Thread, ThreadContext};
+static STACK: StaticStack<512> = StaticStack::new();
+static THREAD: ThreadContext = Thread::context();
+
+#[unsafe(no_mangle)]
+#[doc(hidden)]
+pub extern "C" fn __rust_threadx_app_define() {
+    let instances = teensy4_bsp::board::instances();
+    let mut resources = teensy4_bsp::board::t40(instances);
+
+    let led = teensy4_bsp::board::led(&mut resources.gpio2, resources.pins.p13);
+    Thread::create(
+        Pin::static_ref(&THREAD),
+        STACK.take().unwrap(),
+        &Default::default(),
+        move || loop {
+            fusible::thread::sleep(50);
+            led.toggle();
+        },
+    )
+    .unwrap();
+
+    stdio::start(resources.usb, interrupt::USB_OTG1);
+}
+
+use teensy4_bsp::{ral::interrupt, rt::interrupt};
+
+#[interrupt]
+fn USB_OTG1() {
+    stdio::on_interrupt(interrupt::USB_OTG1);
+}