vkoskiv

Fun fact: At the Assembly demoparty, every system wired to the party network receives a dedicated, publicly routable IPv4 address. It's a lot of fun, but can lead to some interesting moments. One year as I was getting my setup ready, I had a bit of a heart dropping moment when I realized that the raspberry pi I use to bridge ethernet to my Mac Plus over SCSI, the very same one that usually lives on my home network with all kinds of exciting old daemons running, was in fact reachable on the public internet!

Nice! My keyboard code is still very bare bones, so I interact with my system using debug commands assigned to individual keys.

Since we're both working on a similar project, I think it could be fun to talk about OS development and share our findings (and weird bugs!) I have this same username just about everywhere, so do reach out if you're interested! Best of luck with your project either way :]

My hobby x86 kernel. I'm targeting my 80486DX2-66 PC with 32MB of RAM. This project has had a few false starts over the years, where I lacked the prerequisite knowledge to be able to properly debug things. So while the initial commit is from 2020, most of the progress is from the ~180 or so commits I've done in the last month since I picked it up again in early February. A month ago it booted from a floppy and printed some debug info to the screen showing it set up GDT, IDT and some static page tables. Now I have basic virtual memory with kmalloc()/kfree(), task switching, user mode and a few syscalls, and just this past weekend I got my floppy driver to a state where it can now (semi-)reliably detect and read data off floppy disks. I already have a userspace prototype of an ext2 parser I wrote for this in 2024, so all I need to do now is to bring that code in to the kernel and I should have filesystem support!

It's been a ton of fun to work on. Every subsystem is still flaky so I run into the wackiest bugs imaginable. I'm really grateful for the resources[1] and incredible tooling[2] that enable me to work out my frequent mistakes. I can hardly fathom how Torvalds did this with just his PC running Minix!

No idea how long I'll keep working on it. I think I'd be pretty happy if I got a real-world, non-trivial program running on top of it, but in the meantime it is serving as a good distraction from life worries at least :]

[1]: Intel 80386 Reference Manual, Linux man pages, wiki.osdev.org, various datasheets and the occasional query to ChatGPT free tier.

[2]: QEMU+gdb, Bochs, GCC 9 & binutils

I wanted to hold off on that upgrade until I found a source of reliable, high-quality PATA SSDs. Haven't looked into that yet, suggestions welcome!

The joke gets even better when you consider that the subsystem maintainer that reviewed my patch is also Finnish :]

Kiitos!

Thank you! It is indeed!

> For many apps the main source of memory usage isn't stack or heap memory consumed during runtime, it's the loading of the binary itself into memory.

Does iOS not do demand paging?

Wasn't expecting to stay in the top 100 for this long!

Initial C implementation got me to ~70 for a short time, then very sloppy racy pthreads one kept me at the tail end for a bit longer, but my again very sloppy cuda program running on my GTX1070 has me at 35 at the time of writing.

Rough calculation shows it to be doing 28.6MHashes/sec, and I suspect I could do a lot better than that if I knew anything about cuda programming.

I didn't read enough to know how to pick good values for blocks/threads per block, so I just benchmarked all the combinations of powers of two to arrive at the best result.

Really fun challenge!

Would be fun to see the total amount of valid submissions, and maybe the number of leading zeroes of a hash for those of us that need a moment to figure it out from hex in their head :]