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

Package	Provides
clang or gcc	C compiler
musl or glibc	C library (static linking)
util-linux	mount, fsck
kmod	modprobe, lsmod
iproute2	ip command
busybox or coreutils	Basic utilities

Optional Dependencies

Package	Purpose
dhcpcd or dhclient	DHCP client
udev or eudev	Device manager
agetty	Terminal manager
NetworkManager	Network management

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

Command	Description
add <name> <cmd>	Add new service
enable <name>	Enable service
disable <name>	Disable service
start <name>	Start service
stop <name>	Stop service
restart <name>	Restart service
check <name>	Check status (exit 0/1)
list	List all services
poweroff	Power off system
reboot	Reboot system

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

Document	Description
Quick Start	Get started in 5 minutes
Troubleshooting	Common issues and solutions
Migration Guide	Switch from systemd/sysvinit
Service Examples	Ready-to-use service scripts
API Reference	Complete technical reference
Changelog	Version history

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

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minit - Built with simplicity and reliability in mind.

© 2026