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John Carmack's arguments against building a custom XR OS at Meta

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521 points OlympicMarmoto | 1 comments | 29 Aug 25 16:45 UTC | HN request time: 0.227s | source
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jnwatson ◴[29 Aug 25 17:46 UTC] No.45067216[source]▶
I've written a lot of low level software, BSPs, and most of an OS, and the main reason to not write your own OS these days is silicon vendors. Back in the day, they would provide you a spec detailed enough that you could feasibly write your own drivers.

These days, you get a medium-level description and a Linux driver of questionable quality. Part of this is just laziness, but mostly this is a function of complexity. Modern hardware is just so complicated it would take a long time to completely document, and even longer to write a driver for.

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dist1ll ◴[29 Aug 25 22:57 UTC] No.45070345[source]▶
Intel still does it. As far as I can see they're the only player in town that provide open, detailed documentation for their high-speed NICs [0]. You can actually write a driver for their 100Gb cards from scratch using their datasheet. Most other vendors would either (1) ignore you, (2) make you sign an NDA or (3) refer you to their poorly documented Linux/BSD driver.

Not sure what the situation is for other hardware like NVMe SSDs.

[0] 2750 page datasheet for the e810 Ethernet controller https://www.intel.com/content/www/us/en/content-details/6138...

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1. theideaofcoffee ◴[30 Aug 25 18:08 UTC] No.45076796[source]▶
That's interesting that it's that short. I remember a long while ago I had aspirations of implementing a custom board for Prestonia-/Gallatin-era Xeons and the datasheets and specs for those was around 3000 pages, iirc. Supporting infra was about that long as well. So I'm surprised to see a modern ethernet controller fit into the same space. I appreciated all of the docs because it was so open, I felt like I could actually achieve that project, but other things took priority.