HavenDOS™
An independent operating system built from scratch in C and x86 Assembly: a 32-bit monolithic kernel with its own drivers, FAT storage, networking stack, shell and character-based desktop. Boots on BIOS and x86-64 UEFI.
At a glance
- Kernel
- 32-bit x86, monolithic
- Languages
- C and x86 Assembly
- ISO bootloader
- GRUB / Multiboot
- Firmware
- BIOS and x86-64 UEFI
- Interface
- Character-based desktop and shell; framebuffer rendering on UEFI
- Filesystem
- FAT16 on supported disks; exFAT read-only in Helios. NTFS and ext4 are not implemented.
- Storage
- ATA/IDE and VirtIO block
- Network
- RTL8139 and e1000; ARP, ICMP, UDP, TCP, DHCP, DNS
What is HavenDOS?
HavenDOS is a small operating system with its own kernel, hardware drivers, filesystem code, networking stack and desktop utilities. Its latest announced release is 0.8.8.1. It remains a hobby OS with limited hardware support, not a replacement for Windows or Linux. See the release notes for channel, download availability and testing status.
Features
- BIOS and x86-64 UEFI boot paths in one ISO, with GRUB loading the 32-bit kernel
- Framebuffer rendering of the 80×25 interface on UEFI hardware
- Desktop, Shell Mode, Safe Mode and Install to Disk boot entries, plus diagnostics
- Text editor, calculator, calendar, to-do list, settings and hardware information
- CMOS real-time clock
- Disk installer, and ISO-based update and rollback on supported installations
- PCI device enumeration
Hardware
Runs in QEMU, VirtualBox and VMware, and on compatible x86 machines. On 9 October 2026 it booted to its setup screen on an HP laptop with UEFI firmware and no CSM — that confirms the boot path on that machine, not general laptop compatibility. Secure Boot has not been tested.
Current release limitations
- exFAT is read-only; NTFS and ext4 are not implemented
- Fresh installation does not create a firmware boot entry automatically
- USB devices behind hubs may require a manual rescan
- A real TLS handshake is not claimed as tested
- Real HP hardware tests for Helios are still requested; QEMU and suite results do not establish hardware compatibility
Source
The repository contains earlier source archives. Matching Helios source is not yet available at a verified public download. Do not substitute an older source archive for the current release.
Helios Beta release, source availability and hardware-test status · Release history · Running HavenDOS
HavenDOS™ is a trademark of Tech Haven Studios. © Tech Haven Studios.