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Boot Path

Australis OS v0 boots as a custom UEFI application. There is no BIOS boot sector, no stage-1/stage-2 loader, and no GRUB dependency in the current implementation.

UEFI Entry​

The generated binary is placed at:

EFI/BOOT/BOOTX64.EFI

That path is the standard removable-media fallback path for x86_64 UEFI firmware. OVMF discovers and runs it automatically when QEMU exposes the build directory as a FAT drive.

Build Command​

The EFI application is compiled from C# with bflat:

bflat build --stdlib:zero --os:uefi --arch:x64 \
  -o build/efi/EFI/BOOT/BOOTX64.EFI \
  src/boot/Program.cs

--stdlib:zero keeps the runtime surface tiny, and --os:uefi --arch:x64 emits a PE32+ x86_64 EFI application.

QEMU and OVMF​

The run target boots with OVMF firmware:

qemu-system-x86_64 \
  -machine q35 \
  -m 256M \
  -drive if=pflash,format=raw,readonly=on,file=/usr/share/OVMF/OVMF_CODE_4M.fd \
  -drive format=raw,file=fat:rw:build/efi \
  -net none

The FAT drive contains EFI/BOOT/BOOTX64.EFI, so the firmware can boot directly into Australis OS.