Impossible OS Docs
Boot Platform
The UEFI bootloader, the boot_info handoff to the kernel, boot entries and policy, firmware tables, CPU bringup and bare-metal hardening.
Roadmap Overviews
One page per boot-platform roadmap file, each following the page contract.
| Document | Topics |
|---|---|
| Boot Protocol ABI Handoff | boot_info contract, versioning, ABI manifest drift gate |
| UEFI Bootloader Hardening and Secure Boot | Runtime services, UEFI variables, shim chain, SBAT, UKI |
| Bootloader Error Recovery | Fatal-boot screens, NVRAM error codes, history ring, ELF checks |
| Firmware Table Inventory | ACPI, SMBIOS and ESRT catalog, validation, Registry and JSON |
| Boot Device Discovery | Boot device identity, type, partition GUID, fallback chain |
| Boot Media and Installer Handoff | Media role detection and its handoff to the kernel |
| Boot Entries, Menu and Policy | Entry store, policy merge, boot menu, audit, loader variables |
| Alternate Boot Protocols | Why UEFI/GPT is the only supported boot path |
| CPU Boot Sequencing and AP Bringup | INIT/SIPI, per-CPU hardening, online mask lifecycle |
| Bare Metal Boot Hardening | IST stacks, graceful degradation, guarded early-boot stacks |
| Interrupt Architecture and Timers | MADT, LAPIC/IOAPIC, IDT vectors, IRQ API, unified timer HAL |
| Early Entropy and Random Seed | Boot entropy sources, seed handoff, seed file, CSPRNG first key |
| TPM Measured Boot and Attestation | Event log replay, golden baseline, sealing, signed quotes |
| Boot Diagnostics | Named stages, POST codes, cross-boot panic evidence, load log |
| Visual POST Display | Pre-splash stage table, postbars modes, last-boot banner |
| NVMe Storage Driver | NVMe bringup, polled I/O queue, flush and shutdown |
| USB Boot Storage (xHCI) | xHCI controller, device enumeration, USB mass storage |
| USB HID Keyboard and Mouse | Boot-protocol HID reports, dedicated event ring, input merge |
| USB Boot Hardening | SCSI retry, stall recovery, bounded timeouts, slow-media logging |
| USB Zero-Delay Handover | Bootloader-allocated xHCI DMA and kernel inherit |
| A/B Dual-Slot Boot and Rollback | Slot metadata, try counting, rollback, mark-good |
| Recovery Partition | Read-only recovery slot, kernel backup, IXFS checker |
| Boot Watchdog | ACPI WDAT arm, pet and verified disarm |
| BlackBox Service Partition | X:\ log partition, dirty-bit repair, cleanup, retention |
| Network Boot (PXE and HTTP) | Network launch discovery, DHCP capture, TFTP and HTTP probes |
| Hibernation Resume Handoff | Hibernation image format; boot-side resume not built |
| Advanced UEFI Features | Chainload, firmware advisor, W^X, multi-GPU GOP, SMBIOS |
| Boot Validation Matrix | Certification matrix, lint, reboot reliability suite |
| Boot Performance and Health | Step budgets, boot-health.json, boot-trend.json |
Reference Documents
| Document | Topics |
|---|---|
| Boot Protocol Reference | The boot_info handoff contract between BOOTX64.EFI and the kernel |
| boot_info Field Ownership | Which side writes and reads each boot_info field |
| Boot Protocol Changelog | Every BOOT_INFO_VERSION bump and what it changed |
| Boot Error History Ring | Persisted boot error records and how to read them |
| Firmware Tables Wire Format | firmware-tables.json schema |
| Boot Entry Store Schema | On-disk boot entry records |
| Bootstrap and First-Install Seeding | How the first boot entries are created |
| bootcfg | The boot entry store editor |
| Boot Menu | Menu renderer, hotkeys and indicators |
| Boot Policy Merge Order | How boot policy sources combine |
| Boot Policy Audit Schema | Per-boot policy audit and entry-store mutation logs |
| Boot Health Gate | Per-entry health gate that marks a boot entry good |
| Boot Health Wire Format | boot-health.json schema |
| Boot Timeline Wire Format | boot-timeline.json schema |
| Boot Trend Wire Format | boot-trend.json schema |
| OS-Visible Loader Variables | UEFI variables the loader publishes to the OS |
| PCR Allocation and Policy Masks | Which TPM PCRs measure what |
| BlackBox Diagnostic Artifacts | Diagnostic files written under X:\Diag\ |
| Alternate Boot Protocol Policy | Why only UEFI boot is supported, and the compatibility boundary |