Detect
Deadlines, integrity checks and supervised services make failures visible instead of silent.
Bounded · fail-closed · observable
Resilience is a system property.
REIST-OS is a compact 32-bit x86 research operating system built to detect faults, contain damage, recover state, validate the result and only then reintegrate a component.
- Ring-3 isolation
- Bounded recovery
- Real x86 boot
[boot] kernel CRC32 verified
[storage] AHCI controller ready
BOOT_OK
RESOURCE_QUARANTINED 0
media identity verified
undo journal recovered
storage fence released
RESOURCE_REINTEGRATED_RW 0
C:\>_
Engineering principles
Fail closed before side effects.
Every critical path is designed around explicit bounds, protected state and evidence-driven recovery.
Contain
Ring-3 domains, generation-scoped handles and output fences limit the authority of failed components.
Recover
Transactional storage and bounded restart paths restore a known state without blind retries.
Validate
Fresh reads, identity checks, CRCs and self-tests verify the result before capability is restored.
Reintegrate
Read/write access returns only after every required recovery gate has passed.
Diagnose
Build IDs, failure context and bounded panic records turn hardware tests into actionable evidence.
System architecture
Small layers. Explicit authority.
Ring 3Shell · REIST probe · storage service · system toolsVersioned syscalls and bounded IPC
KernelSupervisor · scheduler · VFS · safety domainsProtected control objects and revocation
StorageFAT12 · FAT32 · EXT2 · journal · remapTransactional metadata and fail-closed fencing
HardwareAHCI/SATA · ATA/IDE · FDD · PS/2 · PCI · EthernetBounded polling and explicit device qualification
Verified project status
Runs in VMs and on real BIOS hardware.
REIST boots through its own BIOS/MBR path, runs isolated userspace programs and has completed a real SATA disconnect/reconnect recovery without leaving the volume read-only.
Research scope: REIST-OS is not certified and does not claim general fail-operational or safety-critical suitability.
- VerifiedQEMU AHCI/SATA guest pathBoot, filesystem I/O and Ring-3 recovery probe
- VerifiedReal SATA hotplug recoveryQuarantine, journal recovery and read/write reintegration
- ActiveHigh-Assurance S0 gateFault matrices and hardware evidence are still being expanded
AI transparency
Agent-assisted, human-directed.
REIST-OS is developed with agentic AI assistance to automate as much implementation, testing, documentation and repetitive verification as responsibly possible. This use is disclosed so the origin and review path of project changes remain clear.
AI does not develop REIST-OS without control.
- Work follows explicit architecture contracts, scoped tasks and acceptance gates.
- Generated changes are built, tested, documented and committed with traceable evidence.
- Architecture decisions, safety claims, release decisions and real-hardware validation remain under human direction and review.
- Automation increases coverage and speed; it does not replace engineering responsibility.
Captured from QEMU
The actual system, not a mock-up.
These views are generated automatically from current REIST-OS images and can be refreshed with the repository capture script.
Build and run
One repository. Three targets.
The Windows build produces a raw BIOS disk, a floppy image and a ready-to-run VMware package.
PowerShell
.\scripts\build-windows.ps1 -Target real_hwOutput: build\reist-os.img
REIST-OS
Inspect the mechanisms, not just the claims.
The source, tests, architecture contracts and executable roadmap are available together.