Install a BSD operating system on Canoeboot

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It is assumed here that you are using the SeaBIOS payload, not the GRUB payload; the U-Boot payload may also work, but that is not covered here. The SeaBIOS payload must ideally run in text mode (txtmode images from Canoeboot releases).

This guide pertains to x86 hosts, and does not cover supported CrOS/ARM chromebooks. For ARM targets, you should refer to u-boot documentation - and U-Boot x86 is also available. The U-Boot x86 payload is interesting, because it can in fact boot OpenBSD via UEFI method (U-Boot provides a lightweight UEFI implementation independently of, say, EDK2).

In our context, we are referring to those descendents of 4.4BSD-Lite starting in the early 1990s. On balance, they are about equal to Linux in many ways, and some would argue that they are better (higher code quality). It can be said that the BSDs are the closest we have to true open source Unix systems, since they ultimately descend from that code lineage. For example, the FreeBSD project briefly covers its own history in the Hand Book: https://docs.freebsd.org/en/books/handbook/introduction/#history

Chief among them are:

• FreeBSD (HardenedBSD probably also works)
• NetBSD
• OpenBSD
• DragonFlyBSD (UNTESTED)

TODO: DragonFlyBSD is untested, as of January 2025. It ought to be tested.

Many other BSD systems exist, that are largely derived from these.

BSD operating systems are in wide use today, powering much of the world’s most critical infrastructure, and they’re quite competent laptop/desktop or workstation systems. Some of them have unique features that you can’t find anywhere else (e.g. FreeBSD jails, OpenBSD’s numerous security enhancements, NetBSD’s rump kernel design and clean code quality).

BSD systems are superficially similar to Linux systems, but they are very different under the hood (different kernel designs, different userspace implementations, and so on). However, almost all of the Linux userspace programs that you enjoy using are probably available in the various BSD ports trees, or they can be compiled with little to no modification. This is because, despite the actual differences under the hood, the BSDs and various Linux distros all adhere to the same basic standards (e.g. Single Unix Specification).

If you want to enjoy using a high quality operating system, with many unique features, BSD systems can be quite fun to use, and quite challenging. They tend to have a much more conservative take on implementations, compared to Linux distros, instead opting for technical correctness and minimalism; this is a good thing, because lots of Linux distros these days are extremely bloated. Using a BSD system feels like Linux did in the year 2005, just with much better hardware support, and that’s a good thing; the reason why is that BSD systems simply have fewer users, and a higher concentration of technical users, and this shows when you use it. Linux is much more mass market and has to cater to all sorts of people, and these days Linux distros have to Just Work.

You can look at the documentation of each BSD system and try each one out, to see which one is right for you. Be warned, BSD systems are typically harder to use than Linux systems. Even the most seasoned Linux user will often have a hard time with any BSD, if it’s their first time using a BSD system. This is mitigated by excellent documentation, which is one of the things that the BSDs excel at, but you are expected to read the documentation; many Linux distros try to hold your hand (“it Just Works”), but the BSDs generally don’t do that.

If you’re already a power user on Linux, and comfortable with the more hands-on distros like Arch Linux or Gentoo Linux, you’ll have a much easier time learning a BSD. FreeBSD for example comes completely barebones by default, and you add packages to it, configuring it to your liking, much like Arch Linux; if you’re wily enough, you might also use the CURRENT tree and install all packages by building them from ports (akin to how Gentoo Linux is used).

BSD systems also have much more relaxed licensing than Linux systems, by and large; most of the software in the base system, on any BSD project, will use a permissive license instead of copyleft. They can be regarded as Free Software, but it’s a very different ideology than, say, GNU. Some might argue that this is better, because licensing conflicts are common among copyleft licenses, even among different versions of the GPL. A BSD-style license permits anyone to use the code, without requiring modified versions to ship source code, so it can be said that the BSD license model contains far fewer restrictions. One might say that the BSD systems are more free than GNU/Linux systems.

Basically, your choice to use BSD will likely be based on a combination of technical and/or ideological preferences. But don’t say we didn’t warn you. BSD is hard. On the flip side of that coin, BSD is easy, because it forces you to really learn how your system works; when you become proficient with BSD, you’ll learn everything else much easier, and you may find yourself doing things more efficiently in Linux as well!

That’s enough BSD fanaticism. Please read the following sections, before you embark on your BSD Canoeboot journey:

This page will not tell you how to install BSD systems; that is best left to the documentation for your BSD system. Instead, these next sections cover only the idiosyncrasies of Canoeboot as they relate to BSD:

Your BSD system must support Kernel Mode Setting for your graphics device (most of them do nowadays). The reasons will become apparent, as you read this article.

On x86 platforms, Canoeboot provides the choice of GRUB and/or SeaBIOS payload. GRUB can technically boot BSD kernels, but the code is poorly maintained and unreliable for this use-case scenario; on BIOS systems, GRUB can chainload BSD bootloaders, but on bare metal (as coreboot payload), GRUB can only chainload other coreboot payloads or boot Linux/BSD kernels directly (but direct booting is only really reliable for Linux, in GRUB).

It is recommended that you boot in text mode, with SeaBIOS. You can literally just follow the official installation guides for your BSD system, whether it be FreeBSD, OpenBSD or others.

If you don’t plan to set up Xorg/Wayland, then that’s all you really need to do. For example, you might want to run a headless server, in which case you probably don’t mind running in text mode all the time.

GRUB payload

GRUB can directly boot many BSD systems, but this is ill advisable. You are advised to use either SeaBIOS, and boot a BIOS-based BSD bootloader, or use Canoeboot’s U-Boot payload and use it to boot via UEFI; U-Boot’s bootflow menu can achieve this.

The U-Boot coreboot payload is still experimental, on ARM64 and x86/x86_64, so you should probably use SeaBIOS for now (on x86). U-Boot is the only coreboot payload for Canoeboot on ARM64 motherboards.

It’s still recommended to use SeaBIOS in text mode, but OpenBSD specifically can work with SeaBIOS booting in a coreboot framebuffer, with SeaVGABIOS. In Canoeboot ROM images, this would be SeaBIOS images with corebootfb in the file name.

Make sure to select MBR-style partitioning on the installer, and it will Just Work. GPT partitioning won’t work in OpenBSD, if you use the SeaBIOS payload, but will work if you boot/install it via UEFI boot method with Canoeboot’s U-Boot UEFI payload instead.

If you’re using the GRUB payload but SeaBIOS is available in the boot menu, you can just select SeaBIOS at said menu, and OpenBSD will work fine.

Assumed broken, so please ensure that you boot with SeaBIOS payload in text mode (cbmk ROM images with txtmode in the file name, not corebootfb).

Please boot in text mode. FreeBSD can be configured to use KMS, if you need Xorg or wayland.

One important peculiarity of most Canoeboot systems is: VGA mode support exists, if booting with corebootfb (coreboot’s own framebuffer) and the SeaVGABIOS option ROM used in the SeaBIOS payload; however, the ability to switch modes is not present, which means you can’t switch to text mode either.

Coreboot can start in framebuffer (corebootfb) or INT10H text mode, and it stays in whatever mode was set, unless KMS is used to change the mode. It should be noted that the coreboot framebuffer is not a VGA mode, but instead coreboot implements minimal drivers for hardware that it supports, providing a framebuffer directly in memory, which software (such as GRUB) can simply use.

The BSD bootloaders on x86, in BIOS systems, typically expect text mode startup. It is usually possible to set the console to higher VGA modes, on most systems, but not on most coreboot systems with native video initialisation used, due to the quirks already described. If you see any documentation (in BSD land) pertaining to VESA modes, ignore it entirely; unless you’re using the proprietary VGA ROM for your device, it won’t work, and Canoeboot doesn’t distribute these (instead, coreboot’s own video initialisation is used where possible, or a headless SeaBIOS payload setup is provided, where you would either run it headless or install a graphics card).

Now, this would otherwise mean: no X11/Wayland. If you start in corebootfb mode with SeaVGABIOS, you won’t get a display in BSD bootloaders, and if you boot in text mode, you can’t set VESA modes from BSD. However, you’re in luck:

At least OpenBSD and FreeBSD (possibly others) all have excellent KMS support nowadays; short for Kernel Mode Setting. This avoids the inefficiency of BIOS/UEFI methods, by having the kernel set modes directly. It is based on KMS drivers that the BSD projects ported over from the Linux kernel. With this, you can use X11/Wayland in FreeBSD (and just X11 in OpenBSD, for now).

For example: on FreeBSD, you can install graphics/drm-kmod as a package or from ports, and (for Intel GPUs) do this:

sysrc kld_list+="i915kms"

This creates the following entry in /etc/rc.conf:

kld_list="i915kms"

On FreeBSD it is also recommended that you switch to KMS on the console/TTY; add this to /boot/loader.conf so that you can still use the console after terminating Xorg:

kern.vty=vt

You should not rely on the above instruction (for FreeBSD), because the exact step might change, and it does not go into full detail either. Refer to the documentation provided by your system, to know how KMS is configured.

All of the BSDs have excellent documentation; it’s one of the defining characteristics, versus typical Linux distros.

Aside from this quirk in coreboot, regarding BIOS video modes, the BSDs otherwise work in exactly the same way as you would expect, and you can follow along to their official documentation without much fuss.

No specific or detailed guides will be provided here, because SeaBIOS is fairly self-explanatory; you can otherwise refer to the SeaBIOS documentation.

If you’re flashing a ROM for a machine where seabios_withgrub and seabios_grubfirst ROMs are available, choose seabios_withgrub.

DO NOT USE ROM IMAGES WITH seabios_grubfirst IN THE FILE NAME! These were present in older Canoeboot releases, and supported in previous revisions of the build system, but they did not work for the intended purpose. More info is written on the Canoeboot installation guide. ROM images with seabios_grubfirst in the filename will NOT be included in future Canoeboot releases.

Tianocore is extremely bloated, and unauditable, so it is not included in Canoeboot firmware, but it is the reference UEFI implementation by Intel and contributors. It can boot most BSD systems very well.

More robust ways to provide UEFI services in Canoeboot are to be investigated. Tianocore integration will not be provided officially, in any current or future releases of Canoeboot.

Desktop users on Canoeboot should just install a graphics card, and again boot with SeaBIOS in text mode; however, when you do this, SeaBIOS will execute the VGA option ROM on the card which will provide early video initialisation instead of coreboot’s initialisation, and that VGA ROM will usually implement full INT10H modes, including the ability to set modes in the BIOS (using interrupts), in which case you don’t need to worry about Kernel Mode Setting, but you should still use KMS anyway.

The reason to use KMS is because it’s more efficient. The INT10H service can only be called in Real Mode or Virtual 8086 mode; v8086 is unavailable in long mode (x86_64) and switching into Real Mode just to set VGA modes is extremely expensive computationally speaking. This is why modern kernels (Linux and BSD kernels) do mode setting themselves.

You can learn more about INT10H text/VGA modes here:

https://en.wikipedia.org/wiki/INT_10H

If you use the U-Boot payload, INT10H is irrelevant because you will rely on an EFI framebuffer instead, which U-Boot does provide (piggybacking off of the coreboot framebuffer where one is available).

Regardless of whether you have an EFI framebuffer or INT10H VGA interrupts, the various BSD systems all support KMS so you should be able to use Xorg or Wayland just fine.

All of the BSDs have excellent documentation; it’s one of the defining characteristics, versus typical Linux distros. This is precisely because the BSDs develop everything in-house, so the various components of a BSD system are much more heavily integrated, and this means that they can provide much more reliable documentation; reliable from both the user’s perspective and from the perspective of technical correctness.

Aside from these and other quirks when installing BSD on Canoeboot, the BSDs otherwise work in exactly the same way as you would expect, and you can follow along to their official documentation without much fuss.

No specific or detailed guides will be provided here, because SeaBIOS is fairly self-explanatory; you can otherwise refer to the SeaBIOS documentation.

DO NOT USE ROM IMAGES WITH seabios_grubfirst IN THE FILE NAME! These were present in older Canoeboot releases, and supported in previous revisions of the build system, but they did not work for the intended purpose. More info is written on the Canoeboot installation guide. ROM images with seabios_grubfirst in the filename will NOT be included in future Canoeboot releases.

Markdown file for this page: https://canoeboot.org/docs/bsd/index.md

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