Why chromium OS isn't available in ISO image format?

[Arun Kumar]

Hi Team,

I'm just wondering why chromium OS isn't available in ISO format so that the users can burn it into a disk and install on their machines. I just checked the chromium OS page and it seems that the users have to manually build the OS to try it. Other Linux distributions are offering in ISO format. 

Thanks,

Arun

[Ian Bloss]

You could grab someones prebuilt or build your own image and burn it to a cd.

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[Victor Khimenko]

On Sat, Sep 5, 2015 at 10:46 AM, Arun Kumar <arunku...@gmail.com> wrote:

Hi Team,

I'm just wondering why chromium OS isn't available in ISO format so that the users can burn it into a disk and install on their machines. I just checked the chromium OS page and it seems that the users have to manually build the OS to try it. Other Linux distributions are offering in ISO format. 

Other Linux distributions are designed to run on PC. Chromium OS is designed to run on Chromebooks (Chromeboxes, etc) and Chromebooks don't have a CD-ROM thus CD-ROM image will be more-or-less useless.

Could you install and use ChromeOS on "normal" PC, not a Chromebook? Yes, sure, it's possible, but that's not the supported mode, you are doing that at your own risk.

[Michael McGlothlin]

An ISO is still a standard format people are familiar with. I seldom use physical discs but I use ISO images a lot. For virtual machines, for writing to thumb drives, etc. Or you could plug a drive into a USB port and use a disc - sometimes that's easier.

📱 Michael McGlothlin

[Victor Khimenko]

On Sat, Sep 5, 2015 at 10:11 PM, Michael McGlothlin <mike.mc...@gmail.com> wrote:

An ISO is still a standard format people are familiar with.

Uhm. No. That's popular myth. Bootable ISO is not a standardized format (it's only "standardized" is the XKCD sense: there are bazillion standards which you could use) and it's really hard to create universal bootable media.

 

I seldom use physical discs but I use ISO images a lot. For virtual machines, for writing to thumb drives, etc. Or you could plug a drive into a USB port and use a disc - sometimes that's easier.

May be. But this also introduces huge complexity in the build process. You could read all more-or-less the full story here: http://mjg59.dreamwidth.org/11285.html

If you don't want to read the whole story this one-line summary says it all: "three partition maps, three bootable images, support for BIOS, UEFI and Mac platforms" - that's how your "standard" image looks like. This is indeed fine achievement but it's also incredibly complex and fragile. Someone must test these things and since very few users routinely install ChromiumOS on different kinds of Mac devices something in there will be broken half of the time. Either someone need to dedicate sizable resources to make sure all these tricks don't deteriorate with time or, alternatively, we could stop pretending that ChromeOS supports all these various incompatible boot schemes.

[Michael McGlothlin]

I've made and used ISO images for decades. It may not be an official standard but it's standard enough that it works pretty darn reliably. Images I made in the 90's still boot for me just fine and they boot on pretty much any PC equipment and usually on any modern Apple or virtual machine.

Ill give you that it can get messy when you start dealing with different BIOS, UEFI, etc but usually the discs produced with standard open source tools work. It might not work on 100% but I'd say 90% is realistic with very little effort. I'd not try for 100% but why not cover the low hanging fruit?

📱 Michael McGlothlin

[Victor Khimenko]

On Sat, Sep 5, 2015 at 11:52 PM, Michael McGlothlin <mike.mc...@gmail.com> wrote:

I've made and used ISO images for decades. It may not be an official standard but it's standard enough that it works pretty darn reliably. Images I made in the 90's still boot for me just fine and they boot on pretty much any PC equipment and usually on any modern Apple or virtual machine.

How well do they work on Chromebooks?

 

Ill give you that it can get messy when you start dealing with different BIOS, UEFI, etc but usually the discs produced with standard open source tools work. It might not work on 100% but I'd say 90% is realistic with very little effort. I'd not try for 100% but why not cover the low hanging fruit?

Try to load your "images that you made in the 90's" on Chromebook and you'll know the answer :-)

To make usable images of ChromiumOS in ISO form you'll need to take these "three partition maps, three bootable images, support for BIOS, UEFI and Mac platforms" and add something suitable for Chromebooks to the mix. Perhaps that's doable, perhaps not, but ChromiumOS developers went with "low-hanging fruit" instead: image which could be booted on Chromebooks instead.

[Mike Frysinger]

well, Google Chrome OS is designed to be run on Google Chromebooks and such, but that doesn't really apply to Chromium OS.  the x86-generic/amd64-generic boards are designed to be a bit more portable.

however, Chromium OS does expect to have a writable backing store which a CD cannot provide.  so it'd take some work to support that use case.  off the top of my head, it'd largely center around the stateful partition being mounted as a tmpfs instead (or have a writable overlayfs put on top of it).  it's not infeasible, but it's not exactly trivial either.  patches welcome ;).

-mike

[Michael McGlothlin]

The easiest way to go would probably be to use a loader to get the disc booting and set up the environment and then load COS on top of that. Already a good supply of tools that can do that for Linux, Windows, etc.. and I'd probably worry more about installing from disc and not actually running from disc. If you had an existing image that worked from USB drive you should be able to just wrap it and convince it to install itself from a disc. The fact that the process is initialized from a disc should be pretty much transparent to the installer.

📱 Michael McGlothlin

[Mike Frysinger]

we own the whole startup stack, and all the init/mount logic is in one script (chromeos_startup), so doing the required surgery in there seems to me as the best route to take.

-mike