separate kernel lib and binary

kernel/src/lib.rs

+#![no_std]
+#![feature(abi_x86_interrupt)]
+
+pub mod framebuffer;
+pub mod idt;
+pub mod instructions;
+
+#[panic_handler]
+fn panic_handler(_: &core::panic::PanicInfo) -> ! {
+    instructions::hlt();
+}
+
+pub fn kernel_main(boot_info: &'static mut bootloader_api::BootInfo) -> ! {
+    framebuffer::init(boot_info);
+    framebuffer::clear();
+    framebuffer::print_char(b'H');
+
+    idt::init();
+
+    instructions::hlt();
+}