xous-core

> Rust? Only Rust? Yes, this OS is written in Rust. However, since it has a well-defined ABI, and all services are defined to use `#[repr(C)]`, and the interface is simple primitive enums, it's designed with C-like language support in mind. The hardest part in C is getting an equivalent to `#[repr(C, align(4096))]` which, last time I checked, only let you do alignments up to 64 or so without resorting to linker tricks. > This mechanism seems ripe for squatting attacks There are only a few services with well-known names, and they start up before things like the scheduler are running. Most things go through the nameserver service which supports things like attestation, finite-client limits, and signature checking. > Just use standard ELF. Sure, there's a loader available that lets you run standard ELF files: https://github.com/betrusted-io/

It's not directly funded by the EU, it's funded by NLNet which is only in part funded by the EU. The goal is to collect money from large sources (e.g. EU) from relatively complex subsidiaries that are too big for small projects then dispatch and evaluate. Source : I have an NLNet funded project, so like Xous https://github.com/betrusted-io/xous-core?tab=readme-ov-file... I have such banners at the bottom of my repository.

Safe hardware is super difficult The only project I know of that really actively addressing the end to end problem is Bunnie Huang's precursor. Work seems to be going on low-key: https://github.com/betrusted-io/xous-core

Xous, the OS that runs on the precursor, may be of interest to look at too: https://github.com/betrusted-io/xous-core It is written in Rust and is targeted for a RISC-V

Xous [1][2] is an example of a microkernel written in Rust and inspired by QNX, that we are actively developing. [1] https://betrusted.io/xous-book/ch00-00-introduction.html [2] https://github.com/betrusted-io/xous-core

I have more been thinking about if those Rust OSs could implement WASI and allow running of a larger set of applications rather then natively porting to each OS API. In terms of running Hubris in WebAssembly for testing, why not Renode like Xous does, https://github.com/betrusted-io/xous-core. Seems interesting but also kind of reinventing things. I don't know of a in Rust written WebAssembly runtime that also runs on RISC-V. Wasmer has some outstanding patches.

You might be interested in Precursor and the Betrusted Platform. https://www.crowdsupply.com/sutajio-kosagi/precursor They are trying to have an hardware platform that can be inspected and it is based on an FPGA with a RISC-V Softcore. Its by Bunnie, and he great talks about the choices and why he made them: Keynote: Precursor - Trustable Open Hardware for Everyday Use - Bunnie Huang (https://www.youtube.com/watch?v=Fw5FEuGRrLE) They are also doing their own Rust Message passing OS called Xous that might be of interest. https://github.com/betrusted-io/xous-core

There are more good efforts, the BeTrusted guys are working on Xous, its a microkernel for a phone like device called the Precurser. https://github.com/betrusted-io/xous-core As a embedded service processor OS for a big server rack, Oxide Computer is working on 'HubrisOS'. They seem to have not released it yet, but that will be open sourced. https://github.com/oxidecomputer Those are two efforts where I know real resources are going into.

With 16MB of RAM, Linux seems unlikely to be useful. It's probably easier to think of this as a more powerful, more open, more portable Arduino with hardware crypto accelerators, a display, keyboard, WiFi, and some GPIO pins to plug in additional hardware. They specifically mention that it will be easy to write Rust applications that run on Precursor, but it seems likely to me that there will be other options. (It seems likely that the default "OS" will be based on the Xous microkernel that they're writing: https://github.com/betrusted-io/xous-core) Since the main processor and crypto accelerators are all contained in an FPGA, the adventurous could change the balance of CPU features that are available. It only has a single CPU core partly because of the massive crypto accelerators, from what I understand, so someone could eliminate those

At the risk of wanting this to be something that it's not - what's the reasoning behind not targeting Precursor towards running (embedded) Linux? With a little more RAM it seems like the specs would make it a great fit for Linux, which might allow for a broader ecosystem of use cases? Is there something I'm missing that means developing a new OS (https://github.com/betrusted-io/xous-core/) works better for Precursor? Keen to understand the rationale, cause I think I'm probably missing something here! edit: There's a good explanation on the CrowdSupply page - seems like it's in order to make it a more secure platform: > Simplicity addresses the reality of only having 24 hours in a day. Even though the full source code for the Linux kernel and Firefox is published, nobody has the time to personally review every release for potential securit