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#![no_std]

extern crate x86_64;

pub mod bootinfo;

/// Defines the entry point function.
///
/// The function must have the signature `fn(&'static BootInfo) -> !`.
///
/// This macro just creates a function named `_start`, which the linker will use as the entry
/// point. The advantage of using this macro instead of providing an own `_start` function is
/// that the macro ensures that the function and argument types are correct.
#[macro_export]
macro_rules! entry_point {
    ($path:path) => {
        #[export_name = "_start"]
        pub extern "C" fn __impl_start(boot_info: &'static $crate::bootinfo::BootInfo) -> ! {
            // validate the signature of the program entry point
            let f: fn(&'static $crate::bootinfo::BootInfo) -> ! = $path;

            f(boot_info)
        }
    };
}