minit - Minimal Init System

Version: 1.0.1

A lightweight, reliable init system for Linux with service supervision, automatic filesystem repair, and network configuration.

Features

• 🛠️ Service Supervision - Automatic service restart on failure
• 📁 Auto Filesystem Repair - Automatic fsck with retry mechanism
• 🌐 Network Setup - Automatic interface initialization
• 📦 Kernel Modules - Auto-loading of 65+ essential modules
• 🔌 Device Management - udevd integration
• ⚡ Clean Shutdown - Graceful service termination
• 📝 Service Logging - Automatic logging to /var/log/minit.log (max 100 lines)
• 💾 UEFI Support - Automatic efivarfs mounting for UEFI systems

Requirements

Required Dependencies

Optional Dependencies

Installation

Compilation

# Static build (recommended)
clang -static minit.c -o minit
# Or with gcc
gcc -static minit.c -o minit
# Dynamic build
clang minit.c -o minit

Setup as Init

# Copy to /sbin
sudo cp minit /sbin/init
# Or use as custom init
sudo cp minit /sbin/minit
# Update GRUB (optional)
# Add to /etc/default/grub:
# GRUB_CMDLINE_LINUX="init=/sbin/minit"
sudo update-grub
# Reboot
sudo reboot

⚠️ Warning: Test minit thoroughly before using as primary init. Always have a rescue option.

Usage

Service Structure

/etc/minit/
├── sv/ # Service definitions
│ ├── getty-tty1/
│ │ └── run
│ └── ...
└── service/ # Enabled services (symlinks)
 ├── getty-tty1 -> ../sv/getty-tty1
 └── ...

Creating a Service

# Create service
mkdir -p /etc/minit/sv/myservice
cat > /etc/minit/sv/myservice/run << 'EOF'
#!/bin/sh
exec /usr/bin/mydaemon -f
EOF
chmod +x /etc/minit/sv/myservice/run
# Enable
mservice enable myservice

mservice Commands

Examples

# Check service
mservice check dbus
echo $? # 0=running, 1=stopped
# Control services
mservice start nginx
mservice stop nginx
mservice restart nginx
# Power management
mservice poweroff
mservice reboot

Kernel Modules

Module Sources (in order)

1. /etc/modules-load.d/*.conf
2. /etc/modprobe.d/*.conf
3. /etc/modules
4. Built-in database (65+ modules)

Built-in Modules

Filesystems: ext4, ext3, ext2, xfs, btrfs, f2fs, vfat, ntfs, ntfs3

Network: e1000, e1000e, r8169, r8125, virtio_net, mlx5_core

WiFi: rfkill, rfkill-gpio, cfg80211, mac80211

Storage: ahci, usb_storage, sd_mod, dm_mod, raid1

Example Configuration

# /etc/modules-load.d/network.conf
e1000
r8169
virtio_net
# /etc/modprobe.d/wifi.conf
blacklist rtw88_8822bu
options 88x2bu rtw_switch_usb_mode=0 rtw_led_ctrl=1

Network

minit automatically:

• Mounts /sys and /proc
• Starts udevd
• Brings up all interfaces (lo, eth*, enp*, ens*, wlan*)
• Supports DHCP

Network Service Example

# /etc/minit/sv/network/run
#!/bin/sh
sleep 3
ip link set lo up
ip link set eth0 up
exec dhcpcd -B eth0

WiFi Service Example

# /etc/minit/sv/wifi/run
#!/bin/sh
modprobe cfg80211
modprobe mac80211
modprobe 88x2bu
ip link set wlan0 up
exec wpa_supplicant -i wlan0 -c /etc/wpa_supplicant.conf -O /var/run/wpa_supplicant

Shutdown Process

1. Send SIGTERM to all services
2. Wait 5 seconds for graceful termination
3. Send SIGKILL to remaining processes
4. Sync disks
5. Unmount filesystems
6. Execute reboot/poweroff

Logging

minit automatically logs service events to /var/log/minit.log (or /tmp/minit.log):

• Service startup (only first start, not respawns)
• Service exit and respawn events
• Log rotation: maximum 100 lines

View Logs

# View live
tail -f /var/log/minit.log
# View last 50 lines
tail -50 /var/log/minit.log

Example Log Output

=== minit started (PID 1) ===
[minit] Started /etc/minit/service/getty-tty1/run with PID 501
[minit] Started /etc/minit/service/getty-tty2/run with PID 502
[minit] Service /etc/minit/service/getty-tty1/run (PID 501) exited. Respawning...

UEFI Support

minit automatically mounts efivarfs on UEFI systems:

/sys/firmware/efi/efivars

On BIOS systems, this mount is silently skipped.

Shutdown Output

[minit] === SYSTEM SHUTDOWN INITIATED ===
[minit] Reason: REBOOT
[minit] Stopping services...
[minit] Stopping service 1/6: /etc/minit/service/getty-tty1/run (PID 501) ... done
[minit] Waiting up to 5 seconds for services to stop...
[minit] All services stopped successfully
[minit] Syncing disks...
[minit] Unmounting filesystems...
[minit] *** REBOOTING SYSTEM ***

Default Services

minit creates 6 getty services by default:

• getty-tty1 (Ctrl+Alt+F1)
• getty-tty2 (Ctrl+Alt+F2)
• getty-tty3 (Ctrl+Alt+F3)
• getty-tty4 (Ctrl+Alt+F4)
• getty-tty5 (Ctrl+Alt+F5)
• getty-tty6 (Ctrl+Alt+F6)

Documentation

Quick Links

Web Documentation

Full documentation is also available in the www/ directory. Open www/index.html in a browser.

# View locally
firefox www/index.html
# Or start web server
cd www
python3 -m http.server 8080

License

MIT License - See LICENSE file for details.

Contributing

1. Fork the repository on Codeberg: https://codeberg.org/faron/Minit
2. Create a feature branch
3. Make your changes
4. Submit a pull request

Support

For issues and questions, please open an issue on Codeberg: https://codeberg.org/faron/Minit/issues

minit - Built with simplicity and reliability in mind.

© 2026