Ani-Loader

A high-fidelity bootloader runtime built with Rust and Slint. It's currently designed specifically for my HP OMEN 16 (i7-14650HX / RTX 4060) to provide a seamless, aesthetically pleasing transition from firmware to the kernel via kexec.

I started working on this because the standard GRUB themes were too static, and rEFInd was giving me issues with btrfs.

Features

• Slint-Powered UI: A modern, hardware-accelerated interface featuring Catppuccin color palettes (scriptable, can be riced).

• Btrfs-Native: Built-in logic to parse and mount Btrfs subvolumes (@arch, @sec, etc.) directly from the loader, will later implement other filesystems too.

• Kexec Handoff: Performs a warm reboot into the target kernel, bypassing the slow "cold boot" hardware initialization.

Tech Stack

• Language: Rust (System-level safety & performance)

• Graphics: Slint (Declarative UI with specialized graphics backend)

• Handoff: Linux kexec

• Target Architecture: x86_64 (Optimized for Raptor Lake Refresh)

Repository Structure

.
├── src/                # Rust logic (Mounting, parsing, kexec execution)
├── ui/                 # Slint markup for the high-fidelity UI
├── kernel/             # Custom kernel I'm working on (Source ignored via .gitignore)
├── recomp.sh           # The master build script (Staging, compilation, QEMU testing)
├── launch_gui.sh       # Loads the qemu instance only (Assumes recomp.sh has been run before)
├── Cargo.toml          # Rust dependencies (Slint, Serde, TOML)
└── ani-loader.toml     # The boot configuration blueprint

Quick Start

To build the initramfs.img and test it within the QEMU sandbox:

chmod +x recomp.sh
./recomp.sh

The script handles the Rust compilation, library resolution, staging the initramfs directory tree, and launching the QEMU environment with a mock Btrfs drive. Currently has all 4 of my own boot entries

Configuration

ani-loader looks for a configuration file at /@arch/boot/ani-loader.toml on your physical partition.

Eg.

[[entries]]
name = "Arch [OMEN-Erde]"
os_type = "linux"
subvol = "@arch"
kernel = "/boot/vmlinuz-omen-custom"
initrd = ["/boot/intel-ucode.img"]
cmdline = "root=UUID=your-uuid-here rw rootflags=subvol=@arch quiet splash"

Current Progress

• GUI phase:
  • Slint UI Handoff
• Backend phase:
  • Btrfs Subvolume Mounting
  • Kexec Logic Fix (Multi-initrd support)
• QEMU phase:
  • Setting up launch script with mock mount setup.
• Kernel setup:
  • Compiling my own kernel
  • Driver Integrations
  • Physical hardware deployment (UEFI entry creation)

Info you might appreciate

All the work I did, was inside a mock partition that was btrfs partitioned by me to mimic my actual linux pool partition, so before you try to launch the GUI yourself using qemu, do these things on your setup too:

# Created a 2GB sparse file
truncate -s 2G mock_disk.raw

# Created a single GPT partition
echo "label: gpt" | sfdisk mock_disk.raw
echo "type=0FC63DA1-2637-4062-A410-1559BA770C9A" | sfdisk mock_disk.raw

# Attached the image to a loop device
sudo losetup -Pf mock_disk.raw

# Formatted the first partition as Btrfs (First assumes /dev/loop0, then checks for 'lsblk' if unsure)
sudo mkfs.btrfs -L "ANI_MOCK" /dev/loop0p1

# Mounted the partition root
sudo mkdir -p /mnt/mockmount
sudo mount /dev/loop0p1 /mnt/mockmount

# Created the Erde and Abgrund subvolumes
sudo btrfs subvolume create /mnt/mockmount/@arch
sudo btrfs subvolume create /mnt/mockmount/@sec

# Created the boot directories
sudo mkdir -p /mnt/mockmount/@arch/boot /mnt/mockmount/@sec/boot

# Copied my boot files to @arch
sudo cp /boot/vmlinuz-linux-zen /mnt/mockmount/@arch/boot/
sudo cp /boot/initramfs-linux-zen.img /mnt/mockmount/@arch/boot/
sudo cp /boot/intel-ucode.img /mnt/mockmount/@arch/boot/

# Did the same for @sec
sudo cp /boot/vmlinuz-linux /mnt/mockmount/@sec/boot/vmlinuz-linux
sudo cp /boot/initramfs-linux.img /mnt/mockmount/@sec/boot/initramfs-linux.img

# Drop the TOML into the @arch subvolume (Didn't include Windows and UEFI entries because work remains.)
sudo tee /mnt/mockmount/@arch/boot/ani-loader.toml << 'EOF'
[[entries]]
name = "Arch [Erde]"
os_type = "linux"
subvol = "@arch"
kernel = "/boot/vmlinuz-linux-zen"
initrd = ["/boot/intel-ucode.img", "/boot/initramfs-linux-zen.img"]
cmdline = "root=/dev/vda1 rw rootflags=subvol=@arch quiet splash"

[[entries]]
name = "Arch [Abgrund]"
os_type = "linux"
subvol = "@sec"
kernel = "/boot/vmlinuz-linux"
initrd = ["/boot/intel-ucode.img", "/boot/initramfs-linux.img"]
cmdline = "root=/dev/vda1 rw rootflags=subvol=@sec quiet splash"
EOF

# Sync and detach
sudo umount /mnt/mockmount
sudo losetup -d /dev/loop0

Prerequisites

Ensure you have the necessary build tools and virtualization packages installed (Arch Linux example):

sudo pacman -S --needed base-devel rustup qemu-full btrfs-progs sfdisk cpio 
rustup default stable