# Alpine-based Zero-OS Initramfs

Modern Alpine Linux based approach to building Zero-OS initramfs, replacing the complex build-from-source system with Alpine packages.

## Architecture Overview

This system uses:
- **Alpine Linux LTS** as base system (latest packages, no building from source)
- **Alpine kernel** with embedded essential storage/ethernet modules  
- **GitHub components**: zinit, core-x, seektime, rfs (only custom builds needed)
- **Same init flow**: tmpfs copy approach for compatibility
- **Alpine packages**: All standard tools (busybox, openssh, btrfs-progs, etc.)

## Directory Structure

```
alpine-initramfs/
├── build/                     # Build orchestration
│   ├── Dockerfile.alpine      # Alpine build environment
│   ├── docker-compose.yml     # Build orchestration
│   └── build-initramfs.sh     # Main build script
├── configs/                   # Configuration files
│   ├── packages.txt           # Alpine packages to install
│   ├── kernel-modules.txt     # Essential modules to embed
│   ├── init                   # Custom init script (Alpine → zinit)
│   └── zinit/                 # Zinit service configs (from ../config/etc/zinit/)
├── scripts/                   # Build helper scripts
│   ├── fetch-github.sh        # Download zinit, core-x, seektime, rfs
│   ├── install-packages.sh    # Install Alpine packages to initramfs
│   ├── setup-initramfs.sh     # Create initramfs structure
│   └── build-kernel.sh        # Build kernel with embedded initramfs
├── output/                    # Build artifacts
│   ├── initramfs.cpio.xz      # Generated initramfs
│   ├── vmlinuz.efi            # Final bootable kernel
│   └── modules/               # Kernel modules
└── docs/                      # Documentation
    ├── PACKAGES.md            # Package mapping (old build → Alpine)
    ├── MODULES.md             # Kernel modules reference
    └── BUILD.md               # Build process guide
```

## Build Flow

1. **Alpine Environment**: Setup Alpine LTS build container
2. **Package Installation**: Install all required Alpine packages
3. **GitHub Components**: Fetch zinit, core-x, seektime, rfs from releases
4. **Initramfs Assembly**: Create filesystem structure with same tmpfs approach
5. **Kernel Build**: Compile Alpine kernel with embedded essential modules
6. **Output**: Generate bootable vmlinuz.efi with embedded initramfs

## Quick Start

```bash
cd alpine-initramfs/build
docker compose build
docker compose run --rm builder
# Output: ../output/vmlinuz.efi
```

## Key Advantages

- ✅ **No source compilation** - Use Alpine's maintained packages
- ✅ **Latest versions** - Always current with Alpine package updates  
- ✅ **Faster builds** - Minutes vs hours
- ✅ **Smaller footprint** - Alpine's minimal design
- ✅ **Same functionality** - Identical init flow and service management
- ✅ **Better maintenance** - Package updates handled by Alpine team