Boot Process

How NØNOS boots from power-on to desktop

---

Boot Sequence

Power On
    │
    ▼
┌─────────────────────────────────┐
│     UEFI Firmware               │
│  • POST                         │
│  • Secure Boot check            │
│  • Load BOOTX64.EFI             │
└─────────────────────────────────┘
    │
    ▼
┌─────────────────────────────────┐
│     NØNOS Bootloader            │
│  1. Security initialization     │
│  2. Hardware discovery          │
│  3. Kernel loading              │
│  4. Signature verification      │
│  5. Memory preparation          │
│  6. Exit boot services          │
│  7. Jump to kernel              │
└─────────────────────────────────┘
    │
    ▼
┌─────────────────────────────────┐
│     NØNOS Kernel                │
│  1. VGA/console setup           │
│  2. GDT/IDT initialization      │
│  3. Memory management init      │
│  4. Driver initialization       │
│  5. Self-tests                  │
│  6. Scheduler entry             │
└─────────────────────────────────┘
    │
    ▼
┌─────────────────────────────────┐
│     Desktop Environment         │
└─────────────────────────────────┘

---

Bootloader Phases

Phase 1: Security Initialization

1. Load Ed25519 production public keys

2. Self-test BLAKE3 hashing

3. Self-test Ed25519 verification

4. Check UEFI Secure Boot status

5. Collect hardware entropy (RDRAND)

Phase 2: Hardware Discovery

1. Enumerate PCI devices

2. Initialize graphics output (GOP)

3. Parse ACPI tables

4. Collect CPU information

5. Get memory map from UEFI

Phase 3: Kernel Loading

1. Load kernel binary from ESP

2. Parse ELF headers

3. Extract .nonos.manifest section

4. Extract .nonos.sig section

Phase 4: Cryptographic Verification

1. Compute BLAKE3 hash of kernel

2. Verify Ed25519 signature against embedded keys

3. Validate manifest data

4. (Optional) Verify Groth16 ZK proof

Phase 5: Handoff

1. Prepare BootInfo structure

2. Exit UEFI boot services

3. Jump to kernel entry point

---

BootInfo Structure

Data passed from bootloader to kernel:

Field	Description
framebuffer	Display configuration
memory_map	Physical memory regions
acpi_rsdp	ACPI table pointer
modules	Loaded module info
boot_time	Timestamp
entropy	Hardware random seed

Magic value: 0x4E4F4E4F ("NONO")

---

Kernel Initialization

Early Boot

1. Initialize VGA text output

2. Set up panic handler

3. Load GDT (Global Descriptor Table)

4. Load IDT (Interrupt Descriptor Table)

Memory Setup

1. Parse memory map from BootInfo

2. Initialize physical allocator

3. Set up kernel heap

4. Enable paging

Driver Init

1. Initialize PCI bus

2. Set up interrupt handlers

3. Initialize storage (AHCI/NVMe)

4. Initialize network (if present)

Self-Tests

The kernel runs verification:

[OK] BLAKE3 hash test
[OK] Ed25519 signature test
[OK] Memory allocator test
[OK] Interrupt delivery test

Scheduler Entry

Finally, the scheduler starts and the system is operational.

---

Boot Messages

Expected serial output:

NØNOS Bootloader v0.1.0
Loading kernel...
Verifying signature... OK
Kernel hash: 3f8a...
Exiting boot services
Jumping to kernel

NØNOS Kernel v0.1.0
Initializing GDT... OK
Initializing IDT... OK
Memory: 512MB detected
Running self-tests...
All tests passed
Starting scheduler

---

Security Verification Flow

Kernel Binary
     │
     ├──► BLAKE3 Hash ──► Expected Hash
     │                         │
     └──► Ed25519 Sig ──► Verify with Public Key
                               │
                               ▼
                         Boot if BOTH pass

---

Troubleshooting Boot

Symptom	Likely Cause
No output	UEFI not loading EFI file
"Signature invalid"	Key mismatch or corrupt kernel
Hangs after "Jumping to kernel"	Kernel panic in early init
Black screen	GPU init failed