Brew Kernel is a simple x86_64 kernel that demonstrates basic OS concepts. It features a custom bootloader, VGA text mode output with customizable colors, and basic interrupt handling.

_{Note: This screenshot may be outdated.}

• 64-bit long mode support
• Multiboot2 compliant
• Custom VGA text mode driver with 16-color palette support
• Basic Interrupt Descriptor Table (IDT) implementation
• ASCII character display demo
• Integer output support with signed and unsigned number handling
• Ability to run on actual x86_64 hardware

To build the kernel, you'll need Docker installed on your system. The build environment is containerized to ensure consistency across different systems.

1. First, build the Docker container for the build environment:

cd BrewKernel
docker build buildenv -t brewkernel    

2. Run the build script:

docker run --rm -it -v "$(pwd)":/root/env -w /root/env --platform linux/amd64 brewkernel make build-x86_64    

The build process will create:

• A kernel binary at dist/x86_64/kernel.bin
• A bootable ISO image at dist/x86_64/kernel.iso

You can run the kernel using QEMU:

qemu-system-x86_64 -cdrom dist/x86_64/kernel.iso

Or run Brew on actual hardware.

note: This is not recommended, i am not liable if this software breaks your system, this is completely at YOUR OWN RISK. This software comes with ZERO warranty.

• Step 1: Install BalenaEtcher on your device
  From own testing this should work, if you would like to use DD, then do so. At again, your own risk.

• Step 2: Open BalenaEtcher and choose the kernel.iso, an external USB drive and flash it, this should take a second, if not less.

• Step 3: Find a compatible x86_64 system.

  Tested Hardware:
  HP EliteDesk 705 G4 DM 65W SBKPF 
   CPU:   AMD Ryzen 5 PRO 2400G (8) @ 3.600GHz
   GPU:   AMD ATI Radeon Vega Series (VGA ONLY.)
  

• Step 4: Enable legacy boot in your BIOS

• Step 5: Insert the flashed USB Drive and boot using the legacy boot option NOT UEFI.
  Important Notice: You can only get a display output by using a VGA port for display output, anything other than VGA is NOT supported.

• Step 6: Enjoy the Brew Kernel!

• src/impl/kernel/ - Main kernel implementation
• src/impl/x86_64/ - Architecture-specific code
• src/intf/ - Header files and interfaces
• targets/ - Target-specific files (linker scripts, GRUB config)
• buildenv/ - Docker build environment
• dist/ - Build output directory

• Kernel is loaded at 1MB (0x100000)
• Stack is 16KB
• Page tables are set up for identity mapping

• Resolution: 80x25 characters
• 16-color palette support
• Memory mapped at 0xB8000

• Signed integer printing with negative number handling
• Unsigned integer printing for positive numbers only
• Base-10 (decimal) output format
• Automatic buffer management for any integer size
• Numbers automatically wrapped at screen boundaries

Basic IDT setup with handlers for:

• Division by Zero (Vector 0)
• Debug Exception (Vector 1)
• Page Fault (Vector 14)

If you enjoy this project, and like what i'm doing here, consider buying me a coffee!

Copyright (C) 2024-2025 boreddevhq

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.