ADR-0002: Platform Bring-Up Baseline

Status

Accepted

Context

The project needs a constrained initial target to reduce bring-up complexity and enable fast iteration in emulator-based workflows.

Decision

The initial platform baseline is:

  • x86_64
  • UEFI firmware
  • SMP enabled from the first bring-up architecture
  • QEMU as the primary validation environment

The project-owned bootloader remains the long-term target, but early bring-up may temporarily use a standards-compliant boot handoff if it accelerates kernel validation without importing foreign kernel code.

Consequences

Positive:

  • faster path to early kernel execution
  • reproducible development environment
  • direct alignment with CI and emulator-driven testing

Negative:

  • legacy BIOS is deferred
  • ARM64 work is deferred to a later portability phase
  • some real hardware issues may appear after emulator success

Implementation notes

  • boot information handoff must be versioned from the start
  • early serial output is mandatory
  • the first hardware profile should remain intentionally narrow: timer, interrupt controller, framebuffer or serial, PCIe discovery, and one storage path