bins/hello/src/main.rs


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//! hello — the first rs-dos external binary (ADR 0006 Phase 2 gate).
//!
//! Prints one line through the injected Exports table and exits 0.
//! Exercises the whole chain: PE32+ load, relocation, ABI call, task exit.

#![no_std]
#![no_main]

use rsapi::Exports;

#[panic_handler]
fn panic(_info: &core::panic::PanicInfo) -> ! {
    loop {
        core::hint::spin_loop();
    }
}

/// The image entry point — the loader jumps here with the ABI arguments
/// (exports table, argc, argv).  The conventional UEFI name is kept so
/// the PE looks normal; the signature is the rs-dos ABI.
#[unsafe(no_mangle)]
pub extern "C" fn efi_main(exports: &'static Exports, _argc: usize, _argv: *const rsapi::Arg) -> i32 {
    let msg = b"hello, world - from an external binary";
    let line = rsapi::Line {
        ptr: msg.as_ptr(),
        len: msg.len(),
    };
    if (exports.put_line)(line) {
        0
    } else {
        1
    }
}