bootsmith

This is the tool Rufus refuses to be.

A native macOS arm64 CLI for writing Windows install USB sticks — Windows XP and Windows 7 — without Rosetta, without a Windows VM, without Boot Camp Assistant.

Status

1.0 — released. Windows XP and Windows 7 are hardware-verified end-to-end (XP unattended installs and XP-era AHCI textmode storage included). Caveat: verification so far is on a single test machine (Dell E6410) — treat reliability on other hardware as unproven until the test matrix widens. The 1.0 scope is Windows XP and Windows 7; Windows 2000 is deferred to 1.1 (text-mode install works, but first boot needs a boot.ini repair — see docs/BACKLOG.md). Remaining 1.0 work is release packaging.

Mode	State
Hybrid (Linux/BSD ISO raw write)	✅ working since v0.1; maintained as a utility path, not part of the v1 Windows scope.
Windows 7+ (BOOTMGR chain)	✅ hardware-verified on Dell E6410 with both --boot-record=bootrec (default) and --boot-record=ms-sys; SP1 regression re-run green 2026-05-26. Same code path covers Vista and Win 8/10/11 — auto-classifier routes any ISO with \bootmgr + \sources\install.wim here. Vista hardware-verified on E6410 (2026-05-26).
Windows NT/XP (windows-ntxp)	✅ GRUB4DOS + FiraDisk production path hardware-verified end-to-end on Dell E6410 (2026-05-21).
Windows 2000	⏳ deferred to 1.1. Text-mode install hardware-verified on Dell E6410 (2026-05-22) via GRUB4DOS + SVBus; first boot needs a manual boot.ini rdisk(1)→rdisk(0) repair. See docs/WIN2K_SVBUS.md.
XP unattended installs	✅ hardware-verified on Dell E6410 — --unattended injects WINNT.SIF (product key, computer name, timezone, admin password, EULA). Win2k unattended tracks the 1.1 Win2k work.
XP AHCI textmode storage	✅ hardware-verified on Dell E6410 (2026-05-26) with BIOS SATA mode set to AHCI and the Dell R274723 (Intel iaStor 9.6.4.1002) driver pack. --ahci-driver-dir <path> slipstreams a BYO vendor F6 driver pack into the staged XP.ISO's I386 directory and patches TXTSETUP.SIF/DOSNET.INF so XP treats the driver as inbox. See docs/AHCI_DRIVER.md.
Linux/isolinux	deferred; not a v1 goal.
UEFI-only	deferred; not a v1 goal.

The MBR + FAT32 PBR bytes come from the published mkmsbr crate by default, linked in-process — no external ms-sys binary required. The legacy ms-sys shell-out is still available as --boot-record=ms-sys for byte-equality auditing of Win 7 mode. bootsmith imports it as bootrec::* internally via a Cargo package = "mkmsbr" alias.

See docs/ARCHITECTURE.md for the design, docs/XP_FIRADISK_PIPELINE.md for the active XP recipe, and docs/BACKLOG.md for release blockers and follow-up work.

Why

• UNetbootin requires Rosetta.
• Rufus is Windows-only.
• Boot Camp Assistant was removed on Apple Silicon.
• dd works for hybrid ISOs but silently produces a non-bootable Windows USB.
• Generic ISO writing is already well-served by dd and other tools; old Windows installer media is the awkward gap.

There is currently no native macOS arm64 binary that writes a bootable Windows XP/7 install USB. This is that binary.

Install

# Homebrew
brew install jma24/bootsmith/bootsmith

# Or from crates.io (requires Rust stable)
cargo install bootsmith

# Or build from source
git clone https://github.com/jma24/bootsmith
cd bootsmith
cargo build --release
sudo cp target/release/bootsmith /usr/local/bin/

The published mkmsbr crate is pulled by Cargo automatically, so a plain cargo build --release is enough — no sibling checkout or local bootloader repo is required.

Optional: ms-sys fallback

By default, bootsmith uses the in-process bootrec library for MBR and FAT32 PBR bytes. If you want byte-for-byte equivalence with the upstream tool (useful for auditing or comparison against a known-good Win 7 USB), pass --boot-record=ms-sys and install ms-sys once:

git clone https://gitlab.com/cmaiolino/ms-sys.git /tmp/ms-sys
cd /tmp/ms-sys && make
sudo cp bin/ms-sys /usr/local/bin/
# Or without sudo: export BOOTSMITH_MS_SYS=/tmp/ms-sys/bin/ms-sys

Hybrid mode (Linux/BSD ISOs) does not touch the boot-record path at all.

Notarized signed binaries via GitHub Releases: TODO.

Test prerequisites

The default cargo test only needs Rust. Boot-record-level integration tests (QEMU smoke, ms-sys byte-equality) live in the upstream boot-record crate repo — run them there.

Usage

bootsmith <iso-path> <device>
       [--type=auto|windows|windows-ntxp|windows-2000|linux|hybrid|uefi]
       [--label=<volume-label>]
       [--boot-record=bootrec|ms-sys]
       [--unattended] [--product-key=...] [--admin-password=...] ...
       [--ahci-driver-dir=<f6-folder>]
       [--dry-run]
       [--force]
       [--verbose]
       [--no-verify]

Examples:

sudo bootsmith Win7_SP1.iso /dev/disk8
sudo bootsmith ubuntu-22.04.iso /dev/disk8 --type=hybrid
sudo bootsmith winxp_sp3.iso /dev/rdisk6 --type=windows-ntxp
bootsmith --dry-run Win7_SP1.iso /dev/disk8     # no sudo needed; emits bytes to /tmp

For NT5-class Windows 2000/XP/2003 media, --type=auto resolves to the newer windows-ntxp GRUB4DOS + FiraDisk path. --type=windows-xp remains accepted as a compatibility alias for windows-ntxp. Windows 2000 media is recognized as NT5-class by auto-detect and has an experimental --type=windows-2000 path, but full Win2k install support is deferred to 1.1.

Safety

bootsmith will refuse to write to:

• The boot disk
• Any disk flagged internal: true by DiskArbitration
• Disks larger than 256 GiB without --force

Every write is verified by re-reading and byte-comparing unless --no-verify is passed.

License

MIT. See LICENSE.

Boot record source code lives in the separate mkmsbr repo, with its own clean-room provenance trail.