RedBear-OS/local/AGENTS.md

RED BEAR OS — DERIVATIVE OF REDOX OS

This directory contains ALL custom work on top of mainline Redox. When mainline Redox updates (git pull on the build system repo), this directory is untouched.

DESIGN PRINCIPLE

Red Bear OS is a full fork based on frozen Redox OS snapshots:

• We baseline on a specific Redox OS state and work from immutable, archived sources
• The local/ directory contains our custom work — untouched by any source immutable archived
• First-class configs use redbear-* naming (not my-*, which is gitignored)
• Sources are NEVER auto-immutable archived from upstream — all changes are explicit, human-initiated

FREE/LIBRE SOFTWARE POLICY

Red Bear OS must remain a free/libre project.

• Prefer components that are open-source, freely available to all users, or built in-tree by Red Bear.
• Do not introduce proprietary, source-unavailable, paywalled, or redistributability-restricted dependencies into the tracked system surface.
• When a dependency is dual-licensed under multiple free/open licenses, choose and document the option that is compatible with the Red Bear project surface.
• For the greeter/login stack specifically, the current SHA-crypt verifier path is the pure-Rust sha-crypt crate, licensed MIT OR Apache-2.0; Red Bear treats it under the MIT option for compatibility with the project's free-software policy.

Build flow:

make all CONFIG_NAME=redbear-full
  → mk/config.mk resolves to the active desktop/graphics compile target
  → Desktop/graphics are available only on redbear-full
  → repo cook builds all packages from local sources (offline by default)
  → mk/disk.mk creates harddrive.img with Red Bear branding
  → REDBEAR_RELEASE=0.1.0 ensures immutable, archived sources

Release flow:

# Sources are immutable — build from archives, never from network
./local/scripts/build-redbear.sh redbear-full

# Check for newer Redox snapshots (read-only, no side effects):
./local/scripts/check-upstream-releases.sh

# Provision a new release (explicit, human-initiated only):
./local/scripts/provision-release.sh --ref=<redox-tag> --release=0.2.0

ACTIVE COMPILE TARGETS

The supported compile targets are exactly three. All three work for both make all (harddrive.img) and make live (ISO):

• redbear-full — Desktop/graphics-enabled target (Wayland + KDE + GPU drivers)
• redbear-mini — Text-only console/recovery/install target
• redbear-grub — Text-only target with GRUB boot manager

Desktop/graphics are available only on redbear-full.

RELEASE MODEL (FORK — NOT OVERLAY)

Red Bear OS sources are frozen at release 0.1.0. Sources are immutable and archived in sources/redbear-0.1.0/. Network access during builds is disabled by default.

How releases work:

• Current baseline: 0.1.0 (snapshot of Redox at build-system commit f55acba68)
• All recipe sources are pinned with rev = "..." in recipe.toml
• Archives are stored in sources/redbear-0.1.0/ with a manifest and BLAKE3 checksums
• Builds are offline by default — REPO_OFFLINE=1 COOKBOOK_OFFLINE=true
• New releases are provisioned explicitly via provision-release.sh, never automatically
• Old releases are NEVER deleted — each new release is added alongside existing ones

Checking for new Redox snapshots:

./local/scripts/check-upstream-releases.sh    # Read-only, zero side effects

Provisioning a new release:

./local/scripts/provision-release.sh --ref=<redox-tag> --release=0.2.0 [--dry-run]

Restoring sources from archives:

./local/scripts/restore-sources.sh --release=0.1.0

SOURCE-OF-TRUTH RULE (VERY IMPORTANT)

Treat the repository as two different layers with different durability guarantees:

1. Source archive layer — immutable per release

These paths are expected to be replaced, refetched, or regenerated when upstream changes:

• recipes/*/source/
• most of recipes/ outside our symlinked local/recipes/* release fork
• config/desktop.toml, config/minimal.toml, and other mainline configs
• generated build outputs under target/, build/, repo/, and recipe-local target/*

For relibc specifically, recipes/core/relibc/source/ is upstream-owned working source, not Red Bear’s durable storage location. We may build and validate there, but we must not rely on that tree alone to preserve Red Bear work.

2. Red Bear-owned layer — durable, must survive release provisioning

These paths are our actual long-term source of truth:

• local/patches/ — all durable changes to upstream-owned source trees
• local/recipes/ — Red Bear recipe release fork and new packages
• local/docs/ — Red Bear planning, validation, and integration documentation
• tracked Red Bear configs such as config/redbear-*.toml

If we can fetch fresh upstream sources tomorrow, provision sources from sources/redbear-<release>/, verify local/recipes/*, and rebuild successfully, then the work is in the right place.

If a change exists only inside an upstream-owned recipes/*/source/ tree, then it is not yet preserved, even if the current build happens to pass.

Upstream-first rule for fast-moving components

Some components, especially relibc, are actively evolving upstream. For those areas, Red Bear must prefer the upstream solution whenever upstream already solves the same problem.

That means:

• if our local patch solves a gap that upstream still has, keep the patch carrier
• if upstream lands an equivalent or better solution, prefer upstream and shrink or drop our local patch
• do not keep a Red Bear patch just because it existed first; keep it only while it still provides unique value

For relibc specifically, patch carriers should be treated as temporary compatibility release fork, not a permanent fork strategy.

When upstream Redox already provides a package, crate, or subsystem for functionality that also exists in Red Bear local code, prefer the upstream Redox version by default unless the Red Bear implementation is materially better. Do not grow lower-quality in-house duplicates as a steady state.

For quirks and driver support specifically:

• prefer improving and using the canonical redox-driver-sys path,
• avoid maintaining separate lower-quality quirk engines when the same functionality belongs in redox-driver-sys,
• if duplication is temporarily unavoidable, treat it as convergence work to remove, not as a permanent design.

Daily-upstream-safe workflow

For any change to upstream-owned source:

1. make the minimal working change in the live source tree if needed for validation
2. prove it builds/tests against the real recipe
3. mirror that delta into local/patches/<component>/...
4. update local/docs/... so the provisioning story is explicit
5. assume the live upstream source tree may be thrown away and recreated at any time

The success criterion is therefore:

We can sources are provisioned via provision-release.sh and archived in sources/redbear-/ build the project successfully.

Local recipe priority vs upstream WIP

When Red Bear maintains a local recipe and upstream contains a package with the same name under recipes/wip/*, Red Bear must prefer the local recipe unconditionally.

• Use the local release fork symlink in recipes/*/<name> -> ../../local/recipes/...
• Do not switch back to upstream WIP for active Red Bear builds
• Re-evaluate only when upstream package exits WIP and becomes a normal maintained package

# Automated sync (preferred):
./local/scripts/check-upstream-releases.sh              # Check for new Redox snapshots (read-only)
./local/scripts/provision-release.sh --ref=<tag> --release=0.2.0 --dry-run   # Preview new release
make all CONFIG_NAME=redbear-full             # Rebuild OS

STRUCTURE

redox-master/                  ← git pull updates mainline Redox
├── config/
│   ├── desktop.toml           ← mainline configs (untouched)
│   ├── minimal.toml
│   ├── redbear-full.toml      ← Desktop/graphics target
│   ├── redbear-mini.toml      ← Text-only console/recovery target
│   ├── redbear-grub.toml      ← Text-only with GRUB boot manager
│   ├── redbear-grub-policy.toml ← GRUB policy fragment (bootloader = "grub", efi_partition_size = 16)
│   └── redbear-greeter-services.toml ← Greeter/auth/session-launch wiring fragment
├── recipes/                   ← mainline package recipes (untouched)
├── mk/                        ← mainline build system (untouched)
├── local/                     ← RED BEAR OS custom work
│   ├── AGENTS.md              ← This file
│   ├── config/                ← Legacy configs (my-*, gitignored)
│   ├── recipes/
│   │   ├── core/              ← ext4d (ext4 filesystem scheme daemon + mkfs tool), grub (GRUB 2.12 UEFI bootloader)
│   │   ├── branding/          ← redbear-release (os-release, hostname, motd)
│   │   ├── drivers/           ← redox-driver-sys, linux-kpi (DRM/GPU + Wi-Fi only — NOT USB — NOT input subsystem)
│   │   ├── gpu/               ← redox-drm (AMD + Intel display drivers), amdgpu (C port)
│   │   ├── system/            ← cub, evdevd, udev-shim, redbear-firmware, firmware-loader, redbear-hwutils, redbear-info, redbear-netctl, redbear-quirks, redbear-meta
│   │   │   ├── redbear-sessiond       ← org.freedesktop.login1 D-Bus session broker (zbus-based Rust daemon)
│   │   │   ├── redbear-authd          ← local-user authentication daemon (`/etc/passwd` + `/etc/shadow` + `/etc/group`)
│   │   │   ├── redbear-session-launch ← session bootstrap helper (uid/gid/env/runtime-dir handoff)
│   │   │   ├── redbear-greeter        ← greeter orchestrator package (`redbear-greeterd`, UI, compositor wrapper, staged assets)
│   │   │   ├── redbear-dbus-services  ← D-Bus .service activation files + XML policies
│   │   ├── wayland/           ← Wayland compositor (Phase 2)
│   │   └── kde/               ← KDE Plasma (Phases 3–4)
│   ├── patches/
│   │   ├── kernel/            ← Kernel patches (ACPI, x2APIC)
│   │   ├── base/              ← Base patches (acpid fixes, power methods, pcid /config endpoint)
│   │   ├── relibc/            ← relibc compatibility release fork still needed beyond upstream (eventfd, signalfd, timerfd, waitid, SysV IPC)
│   │   ├── bootloader/        ← Bootloader patches
│   │   └── installer/         ← Installer patches (ext4 filesystem support + GRUB bootloader)
│   ├── Assets/                ← Branding assets (icon, loading background)
│   │   └── images/            ← Red Bear OS icon (1254x1254) + loading bg (1536x1024)
│   ├── firmware/              ← GPU firmware blobs (gitignored, fetched)
│   ├── scripts/
│   │   ├── provision-release.sh   ← Provision new release from Redox ref
│   │   ├── build-redbear.sh   ← Unified Red Bear OS build script
│   │   ├── fetch-firmware.sh  ← Download bounded AMD or Intel firmware subsets from linux-firmware
│   │   ├── test-drm-display-runtime.sh ← Shared bounded DRM/KMS display validation harness
│   │   ├── test-amd-gpu.sh    ← AMD wrapper for the DRM display validation harness
│   │   ├── test-intel-gpu.sh  ← Intel wrapper for the DRM display validation harness
│   │   ├── test-baremetal.sh  ← Bare metal test script
│   │   ├── build-redbear-wifictl-redox.sh ← Build redbear-wifictl for the Redox target with the repo toolchain
│   │   ├── test-iwlwifi-driver-runtime.sh ← Bounded Intel driver lifecycle check inside a target runtime
│   │   ├── test-wifi-control-runtime.sh ← Bounded Wi-Fi control/profile runtime check inside a target runtime
│   │   ├── test-wifi-baremetal-runtime.sh ← Strongest in-repo Wi-Fi runtime check on a real Red Bear target
│   │   ├── validate-wifi-vfio-host.sh ← Host-side VFIO passthrough readiness check for Intel Wi-Fi validation
│   │   ├── prepare-wifi-vfio.sh ← Bind/unbind Intel Wi-Fi PCI function for VFIO validation
│   │   ├── test-wifi-passthrough-qemu.sh ← QEMU/VFIO Wi-Fi validation harness with in-guest checks
│   │   ├── run-wifi-passthrough-validation.sh ← One-shot host wrapper for the full Wi-Fi passthrough validation flow
│   │   ├── package-wifi-validation-artifacts.sh ← Package Wi-Fi validation artifacts into one host-side tarball
│   │   ├── summarize-wifi-validation-artifacts.sh ← Summarize captured Wi-Fi validation artifacts for quick triage
│   │   ├── finalize-wifi-validation-run.sh ← Analyze a Wi-Fi capture bundle and package the final evidence set
│   │   ├── validate-vm-network-baseline.sh ← Static repo-level VM networking baseline check
│   │   ├── test-vm-network-qemu.sh ← QEMU launcher for the VirtIO VM networking baseline
│   │   ├── test-vm-network-runtime.sh ← In-guest runtime check for the VM networking baseline
│   │   ├── test-ps2-qemu.sh ← QEMU launcher for the bounded PS/2 + serio runtime proof
│   │   ├── test-timer-qemu.sh ← QEMU launcher for the bounded monotonic timer runtime proof
│   │   ├── test-lowlevel-controllers-qemu.sh ← Sequential wrapper for bounded low-level controller proofs
│   │   ├── test-usb-maturity-qemu.sh ← Sequential wrapper for bounded USB maturity proofs
│   │   └── test-greeter-qemu.sh ← Bounded QEMU proof for the Red Bear greeter/auth/session surface
│   └── docs/                  ← Integration docs

HOW TO BUILD RED BEAR OS

# Build targets (all three work for both `make all` and `make live`)
./local/scripts/build-redbear.sh redbear-full     # Desktop/graphics target
./local/scripts/build-redbear.sh redbear-mini     # Text-only console/recovery target
./local/scripts/build-redbear.sh redbear-grub     # Text-only with GRUB boot manager

# Or manually:
make all CONFIG_NAME=redbear-full                 # Desktop/graphics → harddrive.img
make all CONFIG_NAME=redbear-mini                 # Text-only → harddrive.img
make all CONFIG_NAME=redbear-grub                 # Text-only + GRUB → harddrive.img

# Live ISO (for real bare metal)
make live CONFIG_NAME=redbear-full                # Full desktop live ISO
make live CONFIG_NAME=redbear-mini                # Text-only mini live ISO
make live CONFIG_NAME=redbear-grub                # Text-only mini live ISO with GRUB

# Or using the helper:
scripts/build-iso.sh redbear-full                 # Full desktop live ISO
scripts/build-iso.sh redbear-mini                 # Text-only mini (default)
scripts/build-iso.sh redbear-grub                 # Text-only + GRUB

# VM-network baseline validation helpers
./local/scripts/validate-vm-network-baseline.sh
./local/scripts/test-vm-network-qemu.sh redbear-mini
# Then run inside the guest:
#   ./local/scripts/test-vm-network-runtime.sh

# Phase 1 runtime-substrate validation (canonical plan: CONSOLE-TO-KDE v4.0)
# firmware-loader, DRM/KMS, time — covers acceptance areas + POSIX compat)
./local/scripts/test-phase1-runtime.sh --qemu redbear-full

# Legacy Phase 1 desktop-substrate validation (still works)
./local/scripts/test-phase1-desktop-substrate.sh --qemu redbear-full

# Phase 1 POSIX compatibility tests (inside guest)
# Run inside the guest after boot:
#   cd /home/user/relibc-phase1-tests && ./test_signalfd_wayland && ./test_timerfd_qt6 && ...
# Or use the test harness:
./local/scripts/test-phase1-runtime.sh --guest

# Legacy Phase 3 runtime-substrate validation (historical P0-P6 numbering; script still works)
./local/scripts/test-phase3-runtime-substrate.sh --qemu redbear-full

# Low-level controller validation
./local/scripts/test-xhci-irq-qemu.sh --check
./local/scripts/test-msix-qemu.sh
./local/scripts/test-iommu-qemu.sh
./local/scripts/test-ps2-qemu.sh --check
./local/scripts/test-timer-qemu.sh --check
./local/scripts/test-lowlevel-controllers-qemu.sh
./local/scripts/test-usb-storage-qemu.sh
./local/scripts/test-usb-qemu.sh --check
./local/scripts/test-usb-maturity-qemu.sh

# The current xHCI proof checks for an interrupt-driven mode in boot logs.
# The current MSI-X proof uses the live virtio-net path in QEMU.
# The current IOMMU proof runs a guest-driven first-use self-test and checks that discovered
# AMD-Vi units initialize and drain events successfully in QEMU.
# The current PS/2 proof checks serio node visibility and then hands off to the existing Phase 3
# input-path checker inside the guest.
# The current timer proof checks that /scheme/time/CLOCK_MONOTONIC advances across two guest reads.
# The aggregate low-level wrapper runs xHCI, IOMMU, PS/2, and timer proofs in sequence.
# The USB storage proof now verifies usbscsid autospawn plus bounded sector-0 readback against a
# host-seeded pattern, while guest-side write verification is still open.
# The aggregate USB wrapper runs xHCI mode, full USB stack, and USB storage readback proofs in sequence.

# Legacy Phase 4 Wayland runtime validation (historical P0-P6 numbering; script still works)
./local/scripts/build-redbear.sh redbear-full
./local/scripts/test-phase4-wayland-qemu.sh
# Then run inside the guest:
#   redbear-phase4-wayland-check

# Legacy Phase 5 desktop/network plumbing validation (historical P0-P6 numbering; script still works)
./local/scripts/build-redbear.sh redbear-full
./local/scripts/test-phase5-network-qemu.sh --check
# Then run inside the guest:
#   redbear-phase5-network-check

# Experimental Red Bear greeter/login validation
./local/scripts/build-redbear.sh redbear-full
./local/scripts/test-greeter-qemu.sh --check
# Then run inside the guest:
#   redbear-greeter-check
#   redbear-greeter-check --invalid root wrong

# Bounded Intel Wi-Fi runtime validation (real target or passthrough guest)
# Host preparation for VFIO-backed guests:
#   sudo ./local/scripts/validate-wifi-vfio-host.sh --host-pci 0000:xx:yy.z --expect-driver iwlwifi
#   sudo ./local/scripts/prepare-wifi-vfio.sh bind 0000:xx:yy.z
# Guest/target packaged checks:
#   redbear-phase5-wifi-check
#   redbear-phase5-wifi-link-check
#   redbear-phase5-wifi-run wifi-open-bounded wlan0 /tmp/redbear-phase5-wifi-capture.json
#   redbear-phase5-wifi-capture wifi-open-bounded wlan0 /tmp/redbear-phase5-wifi-capture.json
#   redbear-phase5-wifi-analyze /tmp/redbear-phase5-wifi-capture.json
# Helper scripts:
#   ./local/scripts/test-wifi-baremetal-runtime.sh
#   ./local/scripts/test-wifi-passthrough-qemu.sh --host-pci 0000:xx:yy.z --check --capture-output ./wifi-passthrough-capture.json
#   ./local/scripts/finalize-wifi-validation-run.sh ./wifi-passthrough-capture.json ./wifi-passthrough-artifacts.tar.gz

# Legacy Phase 6 KDE session-surface validation (historical P0-P6 numbering; script still works)
./local/scripts/build-redbear.sh redbear-full
./local/scripts/test-phase6-kde-qemu.sh --check
# Then run inside the guest:
#   redbear-phase6-kde-check

# redbear-netctl user-facing alias
redbear-netctl --help

# Single custom recipe:
./target/release/repo cook local/recipes/branding/redbear-release
./target/release/repo cook local/recipes/system/redbear-meta
./target/release/repo cook local/recipes/core/ext4d
./target/release/repo cook local/recipes/core/grub  # GRUB bootloader (host build, produces EFI binary)

# GRUB boot manager (installer-native):
make r.grub                                                   # Build GRUB recipe
make all CONFIG_NAME=redbear-grub                             # Build text-only target with GRUB
# Linux-compatible CLI (add local/scripts to PATH):
grub-install --target=x86_64-efi --disk-image=build/x86_64/harddrive.img
grub-mkconfig -o local/recipes/core/grub/grub.cfg
# Or legacy post-build script:
./local/scripts/install-grub.sh build/x86_64/harddrive.img    # Modify existing image

TRACKING MAINLINE CHANGES

When mainline updates affect our work:

Component	What to check	Where
Kernel	ACPI, scheme, memory API changes	recipes/core/kernel/source/src/
relibc	New POSIX functions added upstream	recipes/core/relibc/source/src/header/
Base drivers	Driver API changes	recipes/core/base/source/drivers/
libdrm	DRM API updates	recipes/libs/libdrm/ or the current in-tree libdrm location
Mesa	OpenGL/Vulkan backend changes	recipes/libs/mesa/
Build system	Makefile/config changes	mk/, src/
rsext4	ext4 crate API changes	local/recipes/core/ext4d/source/ Cargo.toml
Installer	ext4 dispatch, filesystem selection, GRUB bootloader	local/patches/installer/redox.patch
Quirks	New Linux quirk entries to port	local/recipes/drivers/redox-driver-sys/source/src/quirks/

PLANNING NOTES

• docs/07-RED-BEAR-OS-IMPLEMENTATION-PLAN.md is the canonical public execution plan.
• local/docs/CONSOLE-TO-KDE-DESKTOP-PLAN.md (v4.0) is the canonical comprehensive plan — supersedes all individual subsystem docs. See it for current state, blockers, and roadmap.
• local/docs/WAYLAND-IMPLEMENTATION-PLAN.md is the canonical Wayland subsystem plan beneath the desktop path. Use it for Wayland-specific stability, completeness, ownership, and runtime-proof sequencing.
• local/docs/DRM-MODERNIZATION-EXECUTION-PLAN.md is the current DRM-focused execution plan beneath the canonical desktop path. It keeps Intel and AMD at the same evidence bar while separating display/KMS maturity from render/3D maturity.
• Older GPU-specific docs such as local/docs/AMD-FIRST-INTEGRATION.md, local/docs/HARDWARE-3D-ASSESSMENT.md, and local/docs/DMA-BUF-IMPROVEMENT-PLAN.md remain useful reference material, but they are not the planning authority when sequencing or acceptance criteria differ.
• local/docs/AMD-FIRST-INTEGRATION.md remains the deeper AMD-specific technical roadmap, but AMD and Intel machines are now equal-priority Red Bear OS targets.
• The earlier Phase 0–3 reassessment bridge has been retired. Its reconciliation role is now covered by local/docs/CONSOLE-TO-KDE-DESKTOP-PLAN.md, local/docs/DESKTOP-STACK-CURRENT-STATUS.md, and docs/07-RED-BEAR-OS-IMPLEMENTATION-PLAN.md.
• local/docs/WIFI-IMPLEMENTATION-PLAN.md is the current Wi-Fi architecture and rollout plan, including the bounded role of linux-kpi and the native wireless control-plane direction.
• local/docs/USB-IMPLEMENTATION-PLAN.md and local/docs/BLUETOOTH-IMPLEMENTATION-PLAN.md should also be treated as first-class subsystem plans, not as side notes.
• local/docs/IRQ-AND-LOWLEVEL-CONTROLLERS-ENHANCEMENT-PLAN.md is the current umbrella plan for IRQ delivery, MSI/MSI-X quality, IOMMU validation, and other low-level controller completeness work.
• local/docs/QUIRKS-SYSTEM.md documents the hardware quirks infrastructure: compiled-in tables, TOML runtime files, DMI matching, driver integration, and the linux-kpi C FFI bridge.
• local/docs/QUIRKS-IMPROVEMENT-PLAN.md is the current follow-up plan for removing quirks drift, integrating quirks into real drivers, and converging on one source of truth.
• local/docs/DBUS-INTEGRATION-PLAN.md is the canonical D-Bus architecture and implementation plan for KDE Plasma 6 on Wayland. It defines the phased approach to D-Bus service integration, the redbear-sessiond login1-compatible session broker, and the gap analysis for desktop-facing D-Bus services.
• local/docs/GREETER-LOGIN-IMPLEMENTATION-PLAN.md is the canonical Red Bear-native greeter/login design and current implementation plan for the redbear-full desktop path. It defines the redbear-authd / redbear-session-launch / redbear-greeter split, service wiring, validation surface, and the current boundary between the active greeter path and the older redbear-validation-session helper flows.

The current execution order for these subsystem plans is:

1. IRQ / low-level controller quality
2. USB maturity
3. Wi-Fi native control plane and first driver family
4. Bluetooth controller + host path
5. desktop/session compatibility on top of those runtime services

Do not present USB, Wi-Fi, Bluetooth, or low-level controller work as optional or secondary.

LINUX KERNEL SOURCE POLICY (CRITICAL)

Linux kernel source is REFERENCE ONLY — never a dependency.

If Red Bear OS needs something from the Linux kernel, it MUST be implemented in the project tree, using Linux source as reference only.

Policy (VERBATIM)

"If we need something from Linux kernel, it MUST be implemented in our tree, having Linux source as reference only" "If we need linux-input-headers than we must code redbear-input-headers"

linux-kpi Scope

local/recipes/drivers/linux-kpi/ covers ONLY:

• DRM/GPU headers (drm/) — AMD + Intel display drivers
• Wi-Fi headers (net/) — mac80211, cfg80211, nl80211
• General kernel headers (linux/) — mm, device, irq, dma-mapping, firmware, etc.

Does NOT cover: USB, input subsystem, or any other Linux kernel subsystem.

Implementing New Linux-Compatibility Headers

When Red Bear needs Linux kernel headers for a new subsystem:

1. Create local/recipes/drivers/redbear-<subsystem>-headers/
2. Implement headers using Linux source as reference only
3. Do NOT pull Linux source tarballs directly
4. Do NOT use third-party tarballs that bundle Linux headers as a proxy
5. Examples:
   • redbear-input-headers/ → linux/input.h, input-event-codes.h, uinput.h
   • redbear-usb-headers/ → linux/usb/ch9.h, etc. (NOT linux-kpi's purpose)

linux-input-headers — Policy Violation

recipes/wip/libs/linux-input-headers/ extracts Linux kernel input headers from the libevdev tarball. This is a policy violation — it pulls Linux headers via a third-party tarball. The correct implementation is redbear-input-headers in local/recipes/drivers/.

FILESYSTEMS

Red Bear OS supports three filesystems:

Filesystem	Implementation	Package	Status
RedoxFS	Mainline Redox (default)	recipes/core/redoxfs	✅ Stable
ext4	rsext4 0.3 crate + ext4d scheme daemon	local/recipes/core/ext4d	✅ Compiles + Installer wired
FAT (VFAT)	fatfs 0.3.6 crate + fatd scheme daemon	local/recipes/core/fatd	✅ Compiles + Tools tested + label write verified

ext4 Workspace (local/recipes/core/ext4d/source/)

ext4d/source/
├── Cargo.toml              ← Workspace: ext4-blockdev, ext4d, ext4-mkfs
├── ext4-blockdev/           ← BlockDevice trait impls for rsext4
│   ├── Cargo.toml           ← Features: default=["redox"], redox=[libredox,syscall]
│   └── src/
│       ├── lib.rs           ← Re-exports: FileDisk, RedoxDisk, Ext4Error, Ext4Result
│       ├── file_disk.rs     ← FileDisk: std::fs backed, builds on host Linux + Redox
│       └── redox_disk.rs    ← RedoxDisk: syscall/libredox backed, Redox-only (feature-gated)
├── ext4d/                   ← ext4 filesystem scheme daemon (Redox userspace)
│   ├── Cargo.toml           ← Features: default=["redox"], redox deps
│   └── src/
│       ├── main.rs          ← Daemon: fork, SIGTERM, scheme registration
│       ├── mount.rs         ← Scheme event loop (redox_scheme::SchemeSync)
│       ├── scheme.rs        ← Full ext4 FSScheme: open, read, write, mkdir, unlink, stat...
│       └── handle.rs        ← FileHandle, DirectoryHandle, Handle types
└── ext4-mkfs/               ← ext4 mkfs tool (host-side utility)
    ├── Cargo.toml
    └── src/main.rs          ← Creates ext4 images via FileDisk + rsext4::mkfs

Architecture:

• ext4d is a Redox scheme daemon — it serves ext4 filesystems via scheme:ext4d
• Uses rsext4 crate (pure Rust ext4 implementation) for all filesystem operations
• FileDisk allows building/testing on the Linux host machine
• RedoxDisk uses libredox + redox_syscall for actual Redox bare-metal I/O
• Both impls are behind the redox feature flag — --no-default-features gives Linux-only

Recipe: Symlinked into mainline search path:

recipes/core/ext4d → local/recipes/core/ext4d

Config: ext4d is included in config/desktop.toml (mainline), which redbear-full.toml inherits.

Dependencies (from workspace Cargo.toml):

• rsext4 = "0.3" — Pure Rust ext4 filesystem implementation
• redox_syscall = "0.7.3" — Redox syscall wrappers (scheme, data types, flags)
• redox-scheme = "0.11.0" — Scheme server framework
• libredox = "0.1.13" — High-level Redox syscalls (open, read, write, fstat)
• redox-path = "0.3.0" — Redox path utilities

Installer ext4 + GRUB Integration (local/patches/installer/redox.patch)

The mainline installer is patched to support ext4 as an install target filesystem and GRUB as an alternative boot manager:

• GeneralConfig.filesystem: Option<String> — TOML field, accepts "redoxfs" (default) or "ext4"
• GeneralConfig.bootloader: Option<String> — TOML field, accepts "redox" (default) or "grub"
• FilesystemType enum — dispatch tag used by install_inner
• with_whole_disk_ext4() — GPT partition layout + ext4 mkfs + file sync (mirrors with_whole_disk)
• Ext4SliceDisk<T> — adapts DiskWrapper to rsext4's BlockDevice trait
• sync_host_dir_to_ext4() — copies staged sysroot files into ext4 filesystem
• GRUB chainload: when bootloader = "grub", writes GRUB EFI + grub.cfg to ESP alongside Redox bootloader
• CLI flags: --filesystem ext4 / --bootloader grub

Usage in config TOML:

[general]
filesystem = "ext4"        # "redoxfs" is default
bootloader = "grub"        # "redox" is default
efi_partition_size = 16    # Required for GRUB (default 1 MiB is too small)
filesystem_size = 10240    # MB

See local/docs/GRUB-INTEGRATION-PLAN.md for the full GRUB architecture and usage guide.

FAT (VFAT) Workspace (local/recipes/core/fatd/source/)

fatd/source/
├── Cargo.toml              ← Workspace: fat-blockdev, fatd, fat-mkfs, fat-label, fat-check
├── fat-blockdev/            ← Block device adapter for fatfs crate
│   ├── src/lib.rs           ← Re-exports: FileDisk (always), RedoxDisk (feature-gated)
│   ├── src/file_disk.rs     ← FileDisk: std::fs::File → Read+Write+Seek
│   └── src/redox_disk.rs    ← RedoxDisk: libredox → Read+Write+Seek (redox feature)
├── fatd/                    ← FAT filesystem scheme daemon (Redox userspace)
│   ├── src/main.rs          ← Daemon: fork, SIGTERM, dispatch to FileDisk/RedoxDisk
│   ├── src/mount.rs         ← Scheme event loop (redox_scheme::SchemeSync)
│   ├── src/scheme.rs        ← FatScheme: full FSScheme (open/read/write/mkdir/unlink/stat...)
│   └── src/handle.rs        ← FileHandle, DirectoryHandle, Handle types
├── fat-mkfs/                ← mkfs.fat equivalent (create FAT12/16/32 filesystems)
│   └── src/main.rs
├── fat-label/               ← fatlabel equivalent (read + write volume labels via BPB)
│   └── src/main.rs          ← `-s "LABEL"` writes label at BPB offset 43/71; verifies round-trip
└── fat-check/               ← fsck.fat equivalent (verify BPB, FAT chains, directory tree + safe repair)
    └── src/main.rs          ← `--repair` clears dirty flag, fixes FSInfo, reclaims lost clusters

Architecture: fatd is a Redox scheme daemon using fatfs v0.3.6 (MIT, no_std capable). FAT is for data volumes and ESP only — NOT for root filesystem. fscommon::BufStream wraps block device for mandatory caching.

Recipe: Symlinked into mainline search path:

recipes/core/fatd → ../../local/recipes/core/fatd

Config: Packages included via config/redbear-device-services.toml (inherited by redbear-full.toml and redbear-mini.toml). Init service at /usr/lib/init.d/15_fatd.service.

Dependencies: fatfs 0.3.6, fscommon 0.1.1, redox_syscall, redox-scheme, libredox, libc

Tool verification status (2026-04-17):

• fat-mkfs: ✅ Creates FAT12/16/32, labels, auto-detection, cluster size option (-c), tested up to 1GB
• fat-label: ✅ Reads labels; writes BPB + creates/updates root-directory volume-label entry; verifies round-trip on all FAT types (including previously unlabeled volumes)
• fat-check: ✅ BPB validation, boot signature check, directory tree walk, cluster stats; ✅ safe repair (dirty flag including FAT12, FSInfo, lost clusters, orphaned LFN). Handles 0xFFFFFFFF FSInfo sentinel on fresh images.
• fatd: ✅ Compiles (links on Redox target only — expected). ✅ frename + rmdir non-empty check implemented. NOT runtime-tested (requires QEMU/bare metal).
• Phase 4 (runtime auto-mount): Deferred to runtime validation. Static init service exists.
• Known limitation: fatfs v0.3.6 strictly requires total_sectors_16 == 0 for FAT32, rejecting some Linux mkfs.fat images
• cargo test: 60 unit tests (25 scheme + 7 label + 28 check) + 13+ integration edge cases

BRANDING ASSETS

Red Bear OS visual identity files live in local/Assets/.

local/Assets/
└── images/
    ├── Red Bear OS icon.png              ← App icon / logo (1254x1254px)
    │                                        Red bear head, dark background, red border
    │                                        Use: desktop icon, bootloader logo, about dialog
    └── Red Bear OS loading background.png ← Boot / loading screen (1536x1024px)
                                             Cinematic red bear with forest silhouette
                                             Use: bootloader splash, login screen background

Integration points (future):

Asset	Target	How
icon.png	Bootloader logo	Convert to BMP, embed via bootloader config
icon.png	Desktop icon	Install to /usr/share/icons/hicolor/ via redbear-release recipe
icon.png	About dialog	Install through the active icon/theme surface
loading background.png	Boot splash	Convert to framebuffer-compatible format, display during startup
loading background.png	Login screen	Set as the display-session background

Current status: Assets are committed to git. Not yet integrated into the build — requires bootloader and display server integration (P2 hardware validation).

BUILD SYSTEM SAFETY

The build system includes collision detection and validation to prevent the D-Bus regression class (config overrides silently overwritten by package staging).

Validation Targets

make lint-config                       # Check for /usr/lib/init.d/ in config [[files]]
make validate CONFIG_NAME=redbear-mini # Full validation: lint + init services + ownership

Init Service Path Convention

• Packages own /usr/lib/init.d/ — default service files from recipe staging
• Config overrides own /etc/init.d/ — override files from [[files]] entries
• Config [[files]] MUST NOT use /usr/lib/init.d/ paths for init services
• The init system's config_for_dirs() gives /etc/init.d/ priority via BTreeMap dedup

Collision Detection (installer)

The installer includes CollisionTracker (in collision.rs) that detects when package staging overwrites config pre-install files. Init service collisions always error. Other collisions warn by default, error in strict mode (REDBEAR_STRICT_COLLISION=1).

Recipe Installs Manifest

Recipes can declare installed paths via installs = [...] in [package] section. scripts/validate-file-ownership.sh checks for conflicts. No recipes declare installs yet.

Manifest Generation

scripts/generate-installs-manifest.sh base  # Output suggested installs for base package

See local/docs/BUILD-SYSTEM-HARDENING-PLAN.md for the full 5-phase hardening plan. See local/docs/BUILD-SYSTEM-INVARIANTS.md for invariants I1-I3.

ANTI-PATTERNS

• DO NOT edit files under mainline recipes/ directly — put patches in local/patches/
• DO NOT commit firmware blobs to git — use local/scripts/fetch-firmware.sh
• DO NOT modify mk/ or src/ directly — extend via local/scripts/
• DO NOT assume mainline recipe names won't conflict — prefix custom ones (e.g., redox-)
• DO NOT use my-* naming for configs that should be tracked in git — use redbear-* instead
• DO NOT edit config/base.toml directly — our configs include it and override via TOML merge
• DO NOT attempt to immutable archived sources from upstream — sources are immutable; use provision-release.sh

COMPREHENSIVE IMPLEMENTATION POLICY

Red Bear OS has zero tolerance for shortcuts, workarounds, and stubs. Every package in the build must be a comprehensive, real implementation. No approximations.

The Rule

When a package fails to build due to missing functionality:

1. DO NOT mark packages as "ignore" to skip them
2. DO NOT create stub recipes that provide fake cmake configs without real functionality
3. DO NOT disable required dependencies via sed/cmake hacks without implementing the dependency

Fix Before Disable

When a build blocker exposes a missing producer surface, missing dependency export, or incomplete integration boundary, the default policy is:

Always do your best to fix before disabling.

This means:

• prefer restoring the real producer/package surface over commenting out the consumer
• prefer fixing CMake/pkg-config/header visibility over disabling the dependent feature
• treat disabling as a last resort, not the normal path

If disabling is temporarily unavoidable, it must be:

• explicit,
• narrowly scoped,
• documented with the real blocker,
• and treated as temporary debt to remove, not as the desired final state.

Instead, implement the missing functionality properly:

Missing Component	Required Action
Missing POSIX function in relibc	Implement it in recipes/core/relibc/source/ + create patch in local/patches/relibc/
Missing KF6 package	Create full recipe in local/recipes/kde/ with proper cmake build
Disabled Qt feature (e.g., QtNetwork)	Implement the feature properly in qtbase recipe
Missing system call	Implement in kernel recipe + create patch in local/patches/kernel/

Why This Matters

• Stubs and workarounds accumulate technical debt
• They block real functionality from ever being implemented
• They make the system unreliable and untestable
• They hide the real work that needs to be done

Current Comprehensive Implementation Gaps

CREDENTIAL SYSCALLS — RESOLVED (2026-04-30): setgroups, getgroups, initgroups, setresuid, setresgid, getrlimit, setrlimit are now implemented. See local/docs/KERNEL-IPC-CREDENTIAL-PLAN.md for the full implementation detail.

Implementation: Kernel: Context.groups: Vec<u32>, CallerCtx.groups, Groups proc scheme handle at auth-{fd}-groups. Relibc: posix_setgroups()/posix_getgroups() in redox-rt, real setgroups()/getgroups() in platform layer, RLIMIT userspace stubs. Durable patches: local/patches/kernel/P4-supplementary-groups.patch, local/patches/relibc/P4-setgroups-getgroups.patch.

Gap	Root Cause	Status
setgroups ENOSYS on Redox	Redox kernel had no supplementary group infrastructure	✅ RESOLVED
getgroups returns only egid	Redox kernel had no group table concept	✅ RESOLVED
setuid/setgid/getuid/getgid	No credential syscalls in kernel	✅ Already worked via posix_setresugid (proc scheme)
getrlimit/setrlimit	ENOSYS	✅ RESOLVED — userspace stubs with defaults
CONFIG: KWin is a stub	KWin recipe attempts real cmake build with QML/Quick disabled. Blocked by QML gate. Previously had wrapper stubs — removed 2026-04-30.	✅ RESOLVED: honest recipe, fails on QML gate
CONFIG: 36/48 KDE packages enabled	12 blocked by QML gate (kirigami → plasma-framework → plasma-workspace → plasma-desktop). See local/docs/CONSOLE-TO-KDE-DESKTOP-PLAN.md for breakdown.	BLOCKED: QML gate requires Qt6Quick/QML engineering
CONFIG: Plasma packages blocked	plasma-framework, plasma-workspace, plasma-desktop depend on kirigami (QML gate). Documented in plan.	BLOCKED: QML gate
CONFIG: Greeter service	20_greeter.service wired. Greeter QEMU proof passes (GREETER_HELLO=ok, GREETER_VALID=ok).	✅ RESOLVED
RUNTIME: Greeter UI	Qt Wayland integration: redbear-compositor handles Wayland protocol. Qt6's Wayland plugin reports loading issues due to endianness in compositor wire format.	DOCUMENTED in plan
RUNTIME: Greeter UI crash	Qt Wayland integration fails (wl-shell deprecated, xdg-shell not working)	Fix Qt platform plugin initialization for Wayland
RUNTIME: D-Bus user lookup	root and messagebus users not found in passwd database → ✅ RESOLVED: user/group config exists in redbear-full.toml; runtime files generated in build	Verify in QEMU runtime
RUNTIME: seatd missing	seatd binary not in image despite being in config → ✅ RESOLVED: seatd builds and is in image	Verify in QEMU runtime
RUNTIME: getrlimit(7)	relibc getrlimit not implemented → ✅ RESOLVED: implemented in relibc patches	Verify in QEMU runtime

Kernel Syscall Gap Analysis

The Redox kernel (recipes/core/kernel/source/src/syscall/mod.rs) match statement ends with:

_ => Err(Error::new(ENOSYS)),

All credential syscalls (SYS_SETGROUPS, SYS_GETGROUPS, SYS_SETUID, SYS_SETGID, etc.) fall through to this catch-all and return ENOSYS.

The syscall numbers come from redox_syscall crate (external, versioned) - not defined in the kernel tree.

Fixes Applied (2026-04-29)

1. relibc/grp/cbindgen.toml: Added group functions to export list
2. relibc/grp/mod.rs: Implemented getgroups() with egid fallback
3. Patches created: local/patches/relibc/P3-grp-cbindgen-exports.patch, P3-getgroups-implementation.patch
4. KERNEL GAP: Cannot fix without upstream redox_syscall + kernel changes

Implementation Locations

• POSIX functions: recipes/core/relibc/source/src/header/<func>/ + local/patches/relibc/
• New KF6 recipes: local/recipes/kde/kf6-<name>/
• Kernel syscalls: recipes/core/kernel/source/ + local/patches/kernel/
• Qt fixes: recipes/qt/qtbase/source/ + local/patches/qtbase/

RED BEAR OS CONFIG HIERARCHY

Active compile targets (all three work for both make all and make live):

• redbear-full — Desktop/graphics-enabled target
• redbear-mini — Text-only console/recovery target
• redbear-grub — Text-only with GRUB boot manager

Desktop/graphics are available only on redbear-full.

redbear-full.toml
  └── redbear-mini.toml
        ├── minimal.toml (mainline)
        ├── redbear-legacy-base.toml
        └── redbear-netctl.toml
  └── [packages] firmware, GPU, Wayland, Qt6, KF6, KWin, greeter, fonts, icons
  └── [services] D-Bus, seatd, greeter, console
  └── [users] messagebus, greeter
  NOTE: ext4d is inherited from desktop.toml (mainline package).
  NOTE: redbear-meta is explicitly included; keep broader inclusion deliberate.

redbear-mini.toml
  └── minimal.toml (mainline)
  └── redbear-legacy-base.toml
  └── redbear-netctl.toml
  └── [packages] pciids, redbear-hwutils, redbear-netctl, redbear-info, cub, etc.
  └── [services] pcid-spawner, netctl boot, console, debug console

redbear-grub.toml
  └── redbear-mini.toml
  └── redbear-grub-policy.toml (bootloader = "grub", efi_partition_size = 16)
  └── [packages] grub

Config comparison:

Config	GPU Stack	Desktop	Branding	ext4d	GRUB	filesystem_size
redbear-full	Full	Yes	Yes	✅	No	4096 MiB
redbear-mini	None	None	Yes	No	No	1536 MiB
redbear-grub	None	None	Yes	No	Yes	(from mini)

ANTI-PATTERNS (COMMIT POLICY)

• DO NOT include AI attribution in commit messages — no "Ultraworked with [Sisyphus]", "Co-authored-by: Sisyphus", or similar AI agent footers. Commits belong to the human author only.