Responding to arping

• Rust nightly-2026-05-31
  • Be sure to add rust-src component, as it will be needed to build rust core library for x86_64-unknown-uefi.
  • Linux host

    % cd /path/to/an-os-in-rust
    % rustup toolchain install nightly-2026-06-26-x86_64-unknown-linux-gnu % rustup override set nightly-2026-06-26-x86_64-unknown-linux-gnu # This sets the toolchain for the an-os-in-rust directory.
    % rustup component add rust-src --toolchain nightly-2026-06-26-x86_64-unknown-linux-gnu  # This adds the `rust-src` component for the nightly toolchain

  • macOS host

    % cd /path/to/an-os-in-rust
    % rustup toolchain install nightly-2026-06-26-aarch64-apple-darwin
    % rustup override set nightly-2026-06-26-aarch64-apple-darwin # This sets the toolchain for the an-os-in-rust directory.
    % rustup component add rust-src --toolchain nightly-2026-06-26-aarch64-apple-darwin  # This adds the `rust-src` component for the nightly toolchain

• An UEFI compatible machine (Tested on QEMU with OVMF)

The following will build both the bootloader and the kernel. Results will be found under target/.

% make

1. Copy the bootloader executable target/x86_64-unknown-uefi/debug/bootx64.efi to \EFI\BOOT\bootx64.efi in your virtual machine's EFI System Partition.
2. Copy the kernel executable target/x86_64-unknown-aosir/debug/aosir to \aosir in your virtual machine's EFI System Partition.
3. Turn on your machine.

   % sudo qemu-system-x86_64 \
     -S \
     -gdb tcp:localhost:1234 \
     -drive if=pflash,format=raw,readonly,file=./qemu/OVMF_CODE-with-csm.fd \
     -hda fat:rw:./qemu/hda \
     -monitor stdio \
     -drive if=pflash,format=raw,file=./qemu/OVMF_VARS-with-csm.fd \
     -d cpu_reset \
     -m 4096 \
     -nic tap,ifname=tap0,model=rtl8139

4. Observe that it does nothing useful ;)
5. If you use arping to broadcast an ARP request, the kernel will respond.

   % sudo arping -I tap0 -U -S 192.168.16.1  192.168.16.40
   ARPING 192.168.16.40
   42 bytes from 52:54:00:12:34:56 (192.168.16.40): index=0 time=13.679 msec
   42 bytes from 52:54:00:12:34:56 (192.168.16.40): index=1 time=7.824 msec
   42 bytes from 52:54:00:12:34:56 (192.168.16.40): index=2 time=6.584 msec
   42 bytes from 52:54:00:12:34:56 (192.168.16.40): index=3 time=4.954 msec
   ...
   ...