This is a pretty big commit, so let's run through it in parts:
- All of the userspace changes are to switch away from syscall_wait
Mostly, this is to waitpid; some things were tweaked to do things
"properly" instead of waiting for particular processes. Init has
been fixed to do a proper spin wait.
- syscall_wait is gone - as are its uses. newlib bindings have been
using just waitpid for a while now.
- waitpid now performs like a Unix waitpid
- process reaping is no longer a "do this on next change thing":
it happens when a process is waited on, like it should
(That means we can have real zombies: terminated processes that
have not yet been waited on)
- Reparenting of children to init has been implemented, so you
can fork-daemonize!
Overall, this is pretty big... So I hope it doesn't break everything.
There's a lot here, so let's through it:
- Lots of work to include a symbol table in the kernel. We can't rely on
our bootloader to give us our own ELF information, so we do this
separately. This probably should be changed to output a C source
rather than assembly, but that's a TODO.
- Makefile can now generate modules. It works basically the same way any
other kernel object works, expect with a slightly different linking
scheme.
- Commands have been added to the debug shell to load modules, but they
don't work yet - still need to get through relocation and linking.
- Commands have been added to the debug shell to print the symbol list,
as well as print symbol values (but note that printing symbol values
is kinda dangerous if you don't know what they are, so don't just go
printing things willy-nilly).
* login should set some environment variables now
* init should start terminals as login shells, so --single doesn't really
mean "single user" any more, just sorta single terminal session
* system() should work now since esh now accepts -c; not that vim is
still going to be unhappy because it does crazy shit.
Also, sleep() as a function (implemented by way of nanosleep) and new
absolute and relative sleep system calls added to newlib.
[ci skip] I damn well know this is going to break CI.
