wrote some ffi functions and interfaces

tested the fact that the rust library could be used in a embedded application

autobar.c

@@ -6,6 +6,11 @@
 
 #include "pico/stdlib.h"
 
+void gpio_put_explict(int pin, bool status) {
+    gpio_put(pin, status);
+    return;
+}
+
 void set_and_sleep(int pin, bool state, int sleep_duration);
 
 int main() {
@@ -13,9 +18,7 @@ int main() {
     gpio_init(LED_PIN);
     gpio_set_dir(LED_PIN, GPIO_OUT);
     while (true) {
-        gpio_put(LED_PIN, 1);
-        sleep_ms(250);
-        gpio_put(LED_PIN, 0);
-        sleep_ms(250);
+        set_and_sleep(LED_PIN, 1, 1000);
+        set_and_sleep(LED_PIN, 0, 1000);
     }
 }

libautobar/Cargo.toml

@@ -1,8 +1,11 @@
 [package]
 name = "libautobar"
-version = "0.1.0"
+version = "0.0.1"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[lib]
+name = "autobar"
+crate-type = ["staticlib"]
 
 [dependencies]

libautobar/src/lib.rs

@@ -1,3 +1,26 @@
+#![no_std]
+
+use core::panic::PanicInfo;
+
+#[panic_handler]
+fn panik(_panic_state: &PanicInfo) -> ! {
+    loop {}
+}
+
+extern {
+    fn gpio_put_explict(pin: i32, status: bool) -> i32;
+    fn sleep_ms(time: i32) -> i32;
+}
+
+#[no_mangle]
+pub extern "C" fn set_and_sleep(pin: i32, status: bool, time: i32) -> () {
+    unsafe {
+        gpio_put_explict(pin, status);
+        sleep_ms(time);
+    }
+}
+
+// this is just a mock test, supposed to pass
 #[cfg(test)]
 mod tests {
     #[test]