v86 VS linux

> As a thought experiment, we're almost there! We could technically have `win95.img + bochs86vm.wasm + autorun.inf + msword.exe` wrapped in a "browser evaluator"

I looked into this and... holy crap! We are there. Not for modern programs quite yet, sure, but this is amazing. You can use Windows 2000 from your browser.

https://copy.sh/v86/?profile=windows2000

I think you are looking for Shadow.

https://shadow.goose.icu

Or just the whole kitchen sink. Why not?

http://copy.sh/v86/?profile=windows98

Also: https://github.com/copy/v86 - more productized browser x86 runtime, used by eg https://github.com/snaplet/postgres-wasm

Wonder if you could put all those databases in a Linux image and boot it using v86 [0], eliminating the need for a server.

[0] https://github.com/copy/v86

Trying it out in https://copy.sh/v86/?profile=kolibrios , it's also clearly a love letter to Windows 95 in particular. That could be an unstated goal here, create a very particular PC experience under very particular constraints. I don't know anything about the creator but it's very possible that this kind of work was actually their career in the 90s.

It's incredible how much work was done. Maybe this should be an internet curiosity like how TempleOS has become, though Terry's personality was a unique factor.

hmm, why would people still use VMWare? Isn't vbox open source, or even things such as https://copy.sh/v86/ would do most virtualization trick now days?

>A pidfd does not let you hold a reference to an individual thread, only to a process

I think that's outdated: https://github.com/torvalds/linux/commit/64bef697d33b75fc06c...

For specific cases I can find ext4 explicitly checking for RO https://github.com/torvalds/linux/blob/8c06da67d0bd3139a97f3...

FFS predates FreeBSD and is in some capacity supported by all 3 major BSDs. I'm fairly confident that Linux actually supports it through the ufs driver ( https://github.com/torvalds/linux/tree/master/fs/ufs ); whether the use of different names in different places makes it better or worse is an exercise for the reader.

These are a bit easier to see what's going on:

https://github.com/torvalds/linux/commit/d5cf50dafc9dd5faa1e...

https://github.com/torvalds/linux/blob/d5cf50dafc9dd5faa1e61...

Unfortunately Github doesn't have a way to render symbols for whitespace, but you can tell by selecting the spaces that the previous version had leading tabs. Linus changed it so that the tokens `default` and the number e.g. `12` are also separated by a tab. This is tricky, because the token "default" is seven characters, it will always give this added tab a width of 1 char which makes it always layout the same as if it were a space no matter if you use tab widths of 1, 2, 4, or 8.

There was also a Gentoo effort to run atop FreeBSD[0]. The challenge of course is that afaik none of the BSD kernel ABIs are considered stable. The stable interface is the BSD libc. That said, with binfmt_misc, I don't see a reason you couldn't just run (at least some) FreeBSD binaries on Linux with a thin syscall translation layer (rather something like qemu-system) and then your layer hooked via binfmt_misc. I'm not aware of anyone who has done this for FreeBSD, but prior efforts existed as alternate binfmts for SysVr4/5 ELF binaries[2]. Either way would take some elbow grease, but you *might* even be able just reuse binfmt_elf and just have a new interpreter for FreeBSD elf.

[0] https://wiki.gentoo.org/wiki/Gentoo_FreeBSD

[1] https://docs.kernel.org/admin-guide/binfmt-misc.html

[2] https://github.com/torvalds/linux/blob/master/fs/binfmt_elf....