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Core2Again v0.1.0

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@jerrybeomsoo jerrybeomsoo released this 26 Sep 16:08
· 2 commits to main since this release
v0.1.0
122fef4

Core2Again v0.1.0

First public source release of Core2Again, the UEFI VMX driver for running Windows 11 on older Intel Core 2 processors. It reports SSE4.2 and POPCNT to the guest, then emulates instructions the physical CPU lacks. SSE4.1 emulation is included for Conroe and Kentsfield processors.

This is a prerelease. An earlier Clover-based diagnostic build reached a Windows 11 desktop on a physical Core 2 Duo T9900 with both cores visible. The EFI files and OpenDuet USB images attached here have been built and tested under QEMU/KVM, but have not yet been booted on that physical machine.

Downloads

  • Core2Again-RELEASE.efi: normal driver, with screen diagnostics compiled out.
  • Core2Again-DEBUG.efi: driver with on-screen checkpoints and counters.
  • Core2Again-singlecore.efi: fallback that leaves other processors alone.
  • Core2Again-apdebug.efi: AP startup diagnostic build.
  • Core2AgainLoader.efi: loads the driver and Windows Boot Manager.
  • core2again-legacy-blockio.img.gz: recommended USB image for a legacy BIOS, using BIOS disk access.
  • core2again-legacy-native.img.gz: USB image using OpenDuet's native storage drivers.
  • Core2Again-v0.1.0-notices.zip: Core2Again, EDK II, and OpenCore license texts.
  • SHA256SUMS: hashes for all of the above.

GitHub also provides the source code as a ZIP and tarball below the assets. The README covers setup; the legacy boot guide covers writing a USB stick and checking a boot failure.

Checks completed

  • Differential emulator suite: 41,179,296 comparisons, zero mismatches.
  • KVM AP trampoline test: one application processor reached C.
  • Static verification: all five EFI variants passed their applicable checks; an intentionally altered RELEASE binary was rejected.
  • SeaBIOS/KVM boot with a preinstalled Windows 11 image: reached the desktop with two virtual CPUs; the per-vCPU kernel check passed.

A QEMU/KVM boot on the development Xeon does not exercise the #UD emulation path because that host executes SSE4.2 directly. The physical T9900 release-image boot remains the next validation step.

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