We only have to allocate at the beginning of the all functions and
can properly exit before any disk reads if we run out of memory.
This makes development little bit 'harder' since the {read,write}_block
user must allocate a buffer of atleast block_size bytes.
I also made disk access to cause kernel panic on error since the error
handling during file write is something I don't want to think now.
The filesystem can easily corrupt so, I feel like when disk io starts
to fail I'll come back to this.
I had misread the format and the parsing code was incorrect. I also
changed fonts to store unicode codepoints as 32 bit integers, so
every character can be represented
We now read from a filesystem to user provided buffer.
Read sizes are determined by read call.
You should now get file descriptors and do reading through Process::current()
This disables interrupts for the current scope and restores them
after the scope. This is used in kmalloc, since scheduler might
call into kmalloc/kfree, but deadlock if some thread is currently
trying to allocate. This allows us to use kmalloc in Scheduler.
This is a big commit that was kinda hard to split to smaller ones.
Essentially we now look at all the mass storage devices from PCI
and initialize (P)ATA devices. This doesn't provide any more functionality
but better abstractions and everything doesn't have to be on its old
default port that might be different for modern computers.
We currently dont have a fallback font if we cannot get to filesystem
initialization, but that will come later. I can't test on real hardware
for this reason.
Performance of the old kmalloc implementation was terrible.
We now use fixed-width linked list allocations for sizes <= 60 bytes.
This is much faster than variable size allocation.
We don't use bitmap scanning anymore since it was probably the slow
part. Instead we use headers that tell allocations size and aligment.
I removed the kmalloc_eternal, even though it was very fast, there is
not really any need for it, since the only place it was used in was IDT.
These changes allowed my psf (font) parsing to go from ~500 ms to ~20 ms.
(coming soon :D)