This is hopefully the last time in a while that
something in the mm subsystem needs a refactor
this large. There are two main changes:
- The page frame allocator returns a vm_page_t
rather than a virtual address.
- Data for the slab allocator is now stored in
struct vm_page, which means there is no overhead
in the slab itself so the space is used in a
more efficient manner.
Another one of those larger endeavours that take
multiple commits. This first one introduces the
basic vm_page data structure, as well as the x86
bootstrap code for initializing it.
As of now, everything except the code imported
from FreeBSD is proprietary. Of course, it won't
be like this for long, only until we have decided
which license we like to use. The rationale is
that releasing everything under a copyleft license
later is always easier than doing so immediately
and then changing it afterwards.
Naturally, any changes made before this commit are
still subject to the terms of the CNPL.
Oh my fucking god this was by far the most awful
and boring and tedious day in my entire life.
Also, dear FreeBSD people: please don't sue me.
I tried really hard to comply with all the
copyright stuff, but it is absolutely possible i
made a mistake. Just DM me and i'll do everything
in my power to fix it, even if that means
releasing entire portions of GayBSD under the BSD
license. I don't care, i just want stuff to work.
(i'm including this message to use it as possible
evidence in case i get sued to show my good will)
So this was painful. kprintf() supports most of
the format specifiers from BSD now, except for the
$ sequence. It has gotten a general overhaul and
is significantly more sophisticated, bloated and
slower now. There is also some minor stuff i
forgot about, like the 't' length modifier, but
that isn't so important right now and will be
fixed later(TM).
This commit also fixes the fun little size bug in
segment.S where i subtracted the end from the
start address of the GDT instead of the other way
round which resulted in a gigantic overflow :)