Kernel Build Notes 🧠

(RTT‑Aware Instrumentation, Not a Kernel Rewrite)

NawderOS does not replace the Linux kernel.
It lightly instruments it.

This document describes where RTT‑aligned hooks live, what they observe, and what they intentionally do not do.

If you can build a custom Linux kernel, you can build NawderOS 🙂

Design Philosophy#

Before touching code, a few ground rules:

We observe, we don’t control
We emit signals, we don’t enforce policy
We prefer tracepoints over logic
We keep patches small and readable

RTT is about coherence over time — not about adding clever behavior to the kernel.

Supported Kernel Baseline#

NawderOS currently targets:

Linux 6.x (LTS preferred)
Vanilla kernel source
No out‑of‑tree dependencies required

If you can build a stock kernel, you’re already 90% there.

Where NawderOS Hooks In 🔧#

NawderOS touches only a few strategic locations:

1️⃣ Boot Path (`init/`)#

Purpose: Substrate alignment check

Capture kernel version, config hash, and boot parameters
Emit a SUBSTRATE_BASELINE badge
No branching, no failure paths

🙂 This answers: “What did we actually boot?”

2️⃣ Scheduler Boundaries (`kernel/sched/`)#

Purpose: Wrap checks on context transitions

Observe task switches
Capture minimal metadata (PID, state, timestamp)
Emit WRAP_CHECK badges on anomalies only

🙂 We don’t care who runs — we care when transitions drift.

3️⃣ Memory Access Boundaries (`mm/`)#

Purpose: Validation corridor observation

Hook into existing fault or boundary logic
Detect access outside declared corridors
Emit CORRIDOR_BREACH badges

🙂 This is not memory protection — it’s memory awareness.

4️⃣ Module Lifecycle (`kernel/module/`)#

Purpose: Substrate drift detection

Observe module load/unload
Compare against declared expectations
Emit SUBSTRATE_DRIFT badges if mismatched

🙂 “Did the system change under our feet?”

How Badges Are Emitted 🏷️#

Badges are events, not logs.

Initial implementations may use:

trace_printk
tracepoints
or a simple ring buffer

Later versions may expose:

/proc/nawderian
tracefs integration
userspace collectors

Badge Emission Rules#

Append‑only
No blocking
No side effects
No policy decisions

If emitting a badge could crash the system, don’t emit it 😄

What NawderOS Does Not Do ❌#

To keep things sane:

No syscall interception
No scheduler modification
No memory allocation changes
No security enforcement
No performance tuning

This is instrumentation, not intervention.

Minimal Patch Strategy 🧩#

A good NawderOS kernel patch should:

Touch as few files as possible
Be readable in one sitting
Be removable without breaking the kernel
Compile cleanly with RTT disabled

If your patch feels “clever,” it’s probably too much.

Build Steps (High Level)#

Clone vanilla Linux kernel
Apply NawderOS patch set
Enable RTT flags in .config
Build kernel as usual
Boot and observe badge output

Detailed commands live in INSTALLATION.md.

Debugging and Safety 🛟#

If something goes wrong:

Disable RTT hooks via config
Rebuild kernel
Boot clean

NawderOS should never prevent a system from booting.

Why This Matters#

RTT becomes real when:

assumptions are visible
drift is observable
coherence can be discussed without guesswork

This kernel layer doesn’t solve anything.
It lets you see what’s happening.

And seeing is the first step 🙂