Comment by treeshateorcs
14 hours ago
i might be wrong but if it's ABI compatible the same drivers will work?
p.s.: i was wrong
>While we prioritize compatibility, it is important to note that Asterinas does not, nor will it in the future, support the loading of Linux kernel modules.
https://asterinas.github.io/book/kernel/linux-compatibility....
Linux doesn't even maintain ABI compatibility with itself, nobody else is going to manage it. The possibility that might work is there's a couple projects that maintain just enough API compatibility to reuse driver code from Linux (IIRC FreeBSD does this for some graphics drivers). But even then you're gambling with whether Linux decides to change implementation details one day, since internal APIs explicitly aren't stable.
The Linux kernel community takes ABI compatibility for userland very seriously. That developers in userland are frequently unwilling to understand issues surrounding ABI stability is not the fault of the Linux kernel.
Oh sure, the user-space ABI is stable; I meant kernel-space. Although I realize now that I failed to write that explicitly.
3 replies →
in general the ABI is kernel<->user space while the ABI (and potentially even API) on the inside (i.e. for drivers) can change with every kernel version (part of why it's so important to maintain drivers in-tree)
They mention this in https://github.com/asterinas/asterinas/blob/2af9916de92f8ca1...
> While we prioritize compatibility, it is important to note that Asterinas does not, nor will it in the future, support the loading of Linux kernel modules.
It's a lot "simpler" to support a Linux userland as that means one needs to "just" emulate all the Linux syscalls, than to implement the literally countless internal APIs needed for drivers etc, as that would otherwise mean literally reimplementing the whole Linux kernel and that's neither realistic, nor too useful.
And that’s not all that simple, as has been experienced by Solaris (never released(?) Linux branded zones, illumos (lx brand), and Windows (WSL1) developers that have tried to make existing kernels act like Linux.
It’s probably easier if the kernel’s key goal is to be compatible with the Linux ABI rather than being compatible with its earlier self while bolting on Linux compatibility.
> emulate all the Linux syscalls
and emulate the virtual filesystems (/proc/...)
No, it means you can run Linux userland/apps on this kernel, to the level/depth which they currently support of course.
They might not yet implement everything that's needed to boot a standard Linux userland but you could say boot straight into a web server built for Linux, instead of booting into init for example.