# Red Bear OS Reference Sources

Reference-only sources for the project. Read-only consultation. Never delete.

## Linux Kernel

- `linux-7.1/` — Latest stable Linux 7.1.1 reference source (2026-06-26).
  Used for: driver implementations (PCI, USB, GPU/DRM, network, input, storage,
  filesystems, scheduler, memory, ACPI, etc.), register definitions, hardware
  initialization sequences, error handling patterns.

  Reference-only. NEVER copied into project source. NEVER built as a dependency.

## Update Procedure

```bash
# Update Linux reference to a newer stable release:
cd local/reference/linux-7.1
git fetch --depth=1 origin tag v7.x
git checkout v7.x
```

## Consultation Pattern

When writing a driver or graphics subsystem, ALWAYS consult the relevant
Linux source first:

- GPU/DRM: `linux-7.1/drivers/gpu/drm/`
- PCI/PCIe: `linux-7.1/drivers/pci/`, `linux-7.1/include/linux/pci.h`
- USB: `linux-7.1/drivers/usb/`
- Network: `linux-7.1/drivers/net/`
- Input: `linux-7.1/drivers/input/`
- Storage: `linux-7.1/drivers/ata/`, `linux-7.1/drivers/nvme/`
- ACPI: `linux-7.1/drivers/acpi/`
- Scheduler: `linux-7.1/kernel/sched/`
- Memory: `linux-7.1/mm/`
- Filesystems: `linux-7.1/fs/`

## Policy

- NEVER copy Linux source files into Red Bear project source
- ALWAYS reimplement needed functionality in Rust (system-critical)
- Use Linux source as documentation/inspiration, not as code
- The `linux-kpi` recipe provides C-header translation only for DRM/GPU
  and Wi-Fi — NOT a wholesale import of Linux code

## Durability

This directory is gitignored but permanent. Survives `make clean` and
`make distclean`. Update procedure documented above.