See https://github.com/rust-osdev/bootloader/issues/107#issuecomment-922407476 Basically: 1. This crate used `asm!` which was renamed to `llvm_asm!` 2. `asm!` was re-introduced with a different API and is the current recommended way to do inline assembly 3. the `x86_64` crate has been updated accordingly: see https://github.com/rust-osdev/x86_64/pull/165