SubX: decide on minimal set of syscalls to support

[tekknolagi]

https://syscalls.kernelgrok.com/

[akkartik]

So far: exit, read, write. Everything is a file, so that should be enough, right? 😛

But seriously we do need at least open and close. And probably the directory and socket calls.

[akkartik]

But we're not going to support them all. Certainly not all the ioctl()s.

[akkartik]

Draft list:

1. ~exit~
2. ~read~
3. ~write~
4. open
5. close
6. creat
7. unlink
8. rename

I was going to add socket ones like bind and accept -- but they aren't syscalls!

[akkartik]

Man, it sucks that POSIX is defined in terms of libc. The operating system interfaces defined in terms of a single language's standard library. Such ugly design. The whole thing is lying to generations of programmers.

[akkartik]

Looks like the socket API is multiplexed through socketcall: http://man7.org/linux/man-pages/man2/socketcall.2.html

Somebody actually mentioned it on Mastodon yesterday: https://social.coop/@h/100450184726157532. But I didn't know what I was looking at.

So we'll add the following:

9. socketcall // socket
10. socketcall // bind
11. socketcall // connect
12. socketcall // listen
13. socketcall // accept
14. socketcall // send
15. socketcall // recv
16. socketcall // shutdown

[akkartik]

17. brk

[tekknolagi]

Suggestion: use a checklist instead of an OL. But I like that idea.

[akkartik]

https://john-millikin.com/unix-syscalls

via https://news.ycombinator.com/item?id=17706119

[akkartik]

Non-socket syscalls are done: https://github.com/akkartik/mu/commit/5cec03b414

[akkartik]

This ticket has probably gone as far as it will go. If necessary we'll open another one for socket syscalls at some point.