I have heard about Redox. What’s the difference between a microkernel and a kernel? Does redox use the linux kernel? Or has the guy written that in rust too?
Well, think microkernels as the bare minimum. They give you just enough to write your own OS on top of that: only the bare essentials run in kernel space, whilst everything else runs in user space and has to communicate with the kernel. Compare this to a monolithic kernel, like the Linux kernel: here, the whole operating system is run in kernel space, which means that data doesn’t need to be moved between user and kernel space: this makes the OS faster, but at the cost of modularity. Redox doesn’t use the Linux kernel, it uses its own microkernel written in Rust.
Edit: A good example would be driver. In a microkernel, these run separately from the kernel and interact with it when needed. In a monolithic kernel, these drivers would be included in the kernel itself. They both have their pros and cons: if you’re interested, feel free to look it up.
Does that mean on a microkernel you’d essentially have double the amount of code execution for a driver (i.e. driver makes a call to the kernel, kernel verifies and then executes rather than the driver just executing the call) meaning double the latency? Seems like it would cause a lot of problems.
No problem! Actually, System76 is currently working on rewriting the COSMIC desktop in Rust (or really, just writing a new DE in Rust). It’s a pretty ambitious project that should hopefully get released some time this year. I wouldn’t be surprised if the lead redox dev was working on it too: low-level Rust knowledge is exactly what they need.
For people who don’t know, there is already a fully Rust OS: https://www.redox-os.org/
Microkernel too which is pretty cool.
IIRC the filesystem was literally just a text file.
I have heard about Redox. What’s the difference between a microkernel and a kernel? Does redox use the linux kernel? Or has the guy written that in rust too?
Well, think microkernels as the bare minimum. They give you just enough to write your own OS on top of that: only the bare essentials run in kernel space, whilst everything else runs in user space and has to communicate with the kernel. Compare this to a monolithic kernel, like the Linux kernel: here, the whole operating system is run in kernel space, which means that data doesn’t need to be moved between user and kernel space: this makes the OS faster, but at the cost of modularity. Redox doesn’t use the Linux kernel, it uses its own microkernel written in Rust.
Edit: A good example would be driver. In a microkernel, these run separately from the kernel and interact with it when needed. In a monolithic kernel, these drivers would be included in the kernel itself. They both have their pros and cons: if you’re interested, feel free to look it up.
Does that mean on a microkernel you’d essentially have double the amount of code execution for a driver (i.e. driver makes a call to the kernel, kernel verifies and then executes rather than the driver just executing the call) meaning double the latency? Seems like it would cause a lot of problems.
Nowhere near double, the kernel can be extremely sparse on it’s side, but there is a small latency hit
thanks for the explanation! I was thought it had something to do with linux since the lead dev works for System76.
No problem! Actually, System76 is currently working on rewriting the COSMIC desktop in Rust (or really, just writing a new DE in Rust). It’s a pretty ambitious project that should hopefully get released some time this year. I wouldn’t be surprised if the lead redox dev was working on it too: low-level Rust knowledge is exactly what they need.
Yeah, I am waiting for a new blog post from them of that.
lots and lots more IPC. So lots and lots of context switches. So worse performance