Hacker Remix

Show HN: My from-scratch OS kernel that runs DOOM

264 points by UnmappedStack 15 hours ago | 62 comments

Hi there! I've been on-and-off working on TacOS for a few months, which follows some UNIX-derived concepts (exec/fork, unix-style VFS, etc) and is now able to run a port of Doom, with a fairly small amount of modifications, using my from-scratch libc. The performance is actually decent compared to what I expected. Very interested to hear your thoughts. Thank you!

NoScopeNinja 45 minutes ago

Really curious to learn more about TacOS. How does it manage running multiple programs safely at the same time?

MisterTea 20 minutes ago

Read up on OS design: https://pages.cs.wisc.edu/~remzi/OSTEP/

Read the intro : https://pages.cs.wisc.edu/~remzi/OSTEP/dialogue-virtualizati...

https://wiki.osdev.org/ has platform details and other resources.

planck_tonne 15 hours ago

Hi, congratulations! You must be feeling proud. Nice choice of proof of concept (DOOM).

Sorry to disappoint you but all I have are some noob questions.

What would be the steps to run this on a laptop? I take it that after building it there would be a process similar to, say, setting up dual-boot in a Windows PC? (Whoa I'm asking a stranger on the Internet how to run dangerous software on my computer...)

If one wanted to undertake such a project, do you have any recommendations of textbooks or other reading material? I had some OS & related courses in university (I'm EE, so computer-adjacent), but they were all very abstract / high level / conceptually-focused. I'd love something more concrete. It doesn't have to be x64.

UnmappedStack 14 hours ago

Not disappointed at all to answer! Running it on my laptop was literally just formatting a USB with the ISO and booting from the USB.

I would recommend checking out https://osdev.wiki to start out if you want to write a kernel, as well as reading relevant specifications (such as Intel Developer Manual and the specs for any drivers you write). I don't really know much about non-x86 kernel dev but most of the concepts are the same as far as I know, just different technical implementations. There's a link to a discord server on the project's readme, there are some very smart people in there who I'm sure would be more than happy to help you out.

khaledh 4 hours ago

I wrote a kernel as well (not complete yet), and I documented all the steps I'm taking. A lot of people found it useful: https://0xc0ffee.netlify.app/osdev

lolinder 12 hours ago

[flagged]

owebmaster 11 hours ago

Not being upvoted to the top doesn't mean downvoted. Your negativity is baseless.

lolinder 11 hours ago

The funny thing about meta comments is that they can change the status quo that they're commenting on (that is, in fact, part of their purpose), and once they've made the change they seem pointless to those who come later.

At the time of commenting this comment was totally grayed out at the bottom. That's a pretty dour welcome for a new user to a community that's ostensibly interested in anything that gratifies curiosity.

pvg 1 hour ago

The funny thing about meta comments is that they can change

Almost always for the worse - for instance now you have this pointless tangent hanging off a topcomment. That's why the site guidelines ask you not to do this.

defrost 11 hours ago

Completely fair point.

I've vouched several green user comments in the past six hours that had been flagged and gone to dead for no apparent reason, the GP comment you spoke for was one that others had kicked to dead ( usually I'm flagging obvious spam comments straight to dead ).

the_hoffa 9 hours ago

Ok, but can your tacos run DOOM??

I kid I kid ;) That's a commendable effort and nice job! Question though: was it an effort to make TacOS using DOOM as a "standard" or was it an effort to make an OS dedicated to running DOOM run from scratch?

And I don't ask from any place but actual curiosity. I made an absolute bare-bones-cant-do-anything-but-boot type OS way back "in the day" (like almost 30 years ago, ack!!!) just for my own education/fun, but the idea of having a dedicated OS that can basically only run DOOM, yet be ported to anything would just make the "can it run DOOM" meme so much more ironic and fun!

Nice stuff! Keep it up!!

UnmappedStack 9 hours ago

Well, it can do a little more than run Doom, that's just the latest milestone as to what was ported last. It wasn't a huge effort, maybe took a week or so to get Doom itself running including adding libc requirements for Doom, but what came before that was a fair bit more groundwork. I used DoomGeneric, which is basically a fork of Doom which is made to be very portable. I hope I answered your question, I might have misunderstood.

NoOn3 52 minutes ago

Great project. Mmap implementation is a cheat :).