Mastodawn

David Chisnall (Now with 50% more sarcasm!)

@david_chisnall@infosec.exchange

2.7K Followers

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6.8K Posts

I am Director of System Architecture at SCI Semiconductor and a Visiting Researcher at the University of Cambridge Computer Laboratory. I remain actively involved in the #CHERI project, where I led the early language / compiler strand of the research, and am the maintainer of the #CHERIoT Platform.

I was on the FreeBSD Core Team for two terms, have been an LLVM developer since 2008, am the author of the GNUstep Objective-C runtime (libobjc2 and associated clang support), and am responsible for libcxxrt and the BSD-licensed device tree compiler.

Opinions expressed by me are not necessarily opinions. In all probability they are random ramblings and should be ignored. Failure to ignore may result in severe boredom and / or confusion. Shake well before opening. Keep refrigerated.

Warning: May contain greater than the recommended daily allowance of sarcasm.

No license, implied or explicit, is granted to use any of my posts for training AI models.

David Chisnall (*Now with 50% more sarcasm!*)17h ago

Graham Sutherland / Polynomial 22h ago

as usual, leave it to the FSF to have the most nonsense contrarian take, like "using a JS based tool to block LLMs is malware".

their slide into incoherence and irrelevance knows no bounds.

David Chisnall (*Now with 50% more sarcasm!*)19h ago

mhoye 1d ago

"America has been vaccinating people for fifty years. If vaccines caused autism, America would have trains, okay? We would have so many trains." - Jon Allen

David Chisnall (*Now with 50% more sarcasm!*)1d ago

CHERIoT Platform 2d ago

Why did you write a new RTOS for CHERIoT? (Part 2)

Back in October last year, I wrote a bit about why we wrote a new RTOS for CHERIoT. Reading that again, I realise that it had a lot of high-level concepts but missed out on some detail. This time, I wanted to take a closer look at some CHERIoT RTOS features to show that being able to rely on CHERI lets us build them in fundamentally different ways to other systems.

#CHERIoT

Why did you write a new RTOS for CHERIoT? (Part 2)

CHERIoT Platform

David Chisnall (*Now with 50% more sarcasm!*)1d ago

mx alex tax1a - 2020 (5)1d ago

still laughing at the xlibre guy not knowing that ^ is xor and c doesn't have a builtin exponentiation operator

this is the kind of thing we learned when we were, idk, 16?

David Chisnall (*Now with 50% more sarcasm!*)1d ago

My wife points out that, although I am very sarcastic person, I am always serious when I use the word 'fabulous'.

David Chisnall (*Now with 50% more sarcasm!*)1d ago

I realised my previous post about why we wrote a new RTOS for #CHERIoT was light on details. The core reason is at the end of the new post: We don't want to build a system that is secure, where people can then layer insecure things on top, we want to build the core that enables you to build secure systems. And that requires rethinking a lot of core OS abstractions with usability and security as core requirements. We can't do that by retrofitting CHERI to an existing system.

Why did you write a new RTOS for CHERIoT? (Part 2)

CHERIoT Platform

David Chisnall (*Now with 50% more sarcasm!*)1d ago

SellaTheChemist 1d ago

Nice to see that my faculty has at last caught up with my little Royal Society stunt.

David Chisnall (*Now with 50% more sarcasm!*)1d ago

abadidea 1d ago

a blog post by my friend eevee which is, y’know, preaching to the choir about exactly what you think, but. yeah. https://eev.ee/blog/2025/07/03/the-rise-of-whatever/

The rise of Whatever

This was originally titled “I miss when computers were fun”. But in the course of writing it, I discovered that there is a reason computers became less fun, a dark thread woven through a number of events in recent history. Let me back up a bit.

David Chisnall (*Now with 50% more sarcasm!*)1d ago