Commit Graph

33 Commits

Author SHA1 Message Date
Andreas Kling
260b14e505 Implement errno in LibC.
This also meant I had to implement BSS (SHT_NOBITS) sections in ELFLoader.
I also added an strerror() so we can print out what the errors are.
2018-10-25 12:06:50 +02:00
Andreas Kling
434b6a8688 Unify the Task constructors.
There's now Task::create() and Task::createKernelTask().
2018-10-25 11:17:47 +02:00
Andreas Kling
de7c54545a Remove age-old IPC stuff that wasn't working anyway.
I'll make a fresh start with IPC code when I get there.
2018-10-25 10:39:39 +02:00
Andreas Kling
ce126120d1 Add a few more InterruptDisablers. 2018-10-25 10:33:10 +02:00
Andreas Kling
16f318408d ELFLoader should fail with an error message for unresolved symbols. 2018-10-25 10:02:04 +02:00
Andreas Kling
ec1d16b307 Add a "pwd" utility to userland.
It's implemented as a separate process. How cute is that.
Tasks now have a current working directory. Spawned tasks inherit their
parent task's working directory.
Currently everyone just uses "/" as there's no way to chdir().
2018-10-24 14:28:22 +02:00
Andreas Kling
5f36a5f22e Add an lstat() syscall and use it to make "ls" nicer. 2018-10-24 13:19:36 +02:00
Andreas Kling
bca4b71bfa Lots of hacking to make a very simple "ls" utility.
I added a dead-simple malloc that only allows allocations < 4096 bytes.
It just forwards the request to mmap() every time.

I also added simplified versions of opendir() and readdir().
2018-10-24 12:50:07 +02:00
Andreas Kling
0c5bbac86e Add an InterruptDisabler helper class and use that for kmalloc.
The naive spinlock was not nearly enough to protect kmalloc from
reentrancy problems.

I don't want to deal with coming up with a fancy lock for kmalloc
right now, so I made an InterruptDisabler thingy instead.
It does CLI and then STI iff interrupts were previously enabled.
2018-10-24 11:07:53 +02:00
Andreas Kling
9a296d63f3 Add simplified mmap() and munmap() syscalls. 2018-10-24 09:48:41 +02:00
Andreas Kling
a5caf7ca99 Make the kmalloc global stats variable volatile.
I know I'm praying for cargo here, but this does fix a weird issue
where logging the sum_alloc and sum_free globals wouldn't display
symmetric values all the time.
2018-10-24 01:04:06 +02:00
Andreas Kling
3253a23b91 Add a simplified waitpid() so that sh can wait on spawned commands. 2018-10-24 00:20:34 +02:00
Andreas Kling
018da1be11 Generalize the SpinLock and move it to AK.
Add a separate lock to protect the VFS. I think this might be a good idea.
I'm not sure it's a good approach though. I'll fiddle with it as I go along.

It's really fun to figure out all these things on my own.
2018-10-23 23:34:05 +02:00
Andreas Kling
d90d125dfe Add an undertaker task that is responsible for destroying dead tasks. 2018-10-23 15:43:05 +02:00
Andreas Kling
ccd15e0590 Various things:
- putch syscall now directly calls Console::putChar().
- /proc/summary includes some info about kmalloc stats.
- Syscall entry is guarded by a simple spinlock.
- Unmap regions for crashed tasks.
2018-10-23 15:19:02 +02:00
Andreas Kling
63e253bac9 Generate a basic /proc/summary file with some info about all tasks. 2018-10-23 12:44:46 +02:00
Andreas Kling
ed2422d7af Start adding a basic /proc filesystem and a "ps" utility. 2018-10-23 12:04:03 +02:00
Andreas Kling
fe237ee215 Lots of hacking:
- Turn Keyboard into a CharacterDevice (85,1) at /dev/keyboard.
- Implement MM::unmapRegionsForTask() and MM::unmapRegion()
- Save SS correctly on interrupt.
- Add a simple Spawn syscall for launching another process.
- Move a bunch of IO syscall debug output behind DEBUG_IO.
- Have ASSERT do a "cli" immediately when failing.
  This makes the output look proper every time.
- Implement a bunch of syscalls in LibC.
- Add a simple shell ("sh"). All it can do now is read a line
  of text from /dev/keyboard and then try launching the specified
  executable by calling spawn().

There are definitely bugs in here, but we're moving on forward.
2018-10-23 10:12:50 +02:00
Andreas Kling
b824f15619 Launching an arbitrary ELF executable from disk works! :^)
This is so cool! It's a bit messy now with two Task constructors,
but eventually they should fold into a single constructor somehow.
2018-10-22 15:43:02 +02:00
Andreas Kling
85bcf2ed0f Add getgid() and getpid() syscalls. Prep for LibC. 2018-10-22 13:55:11 +02:00
Andreas Kling
3a3c57357c Add a sys$exit and make init_stage2 call it when finished. 2018-10-22 11:43:55 +02:00
Andreas Kling
79ffdb7205 A lot of hacking:
- More work on funneling console output through Console.
- init() now breaks off into a separate task ASAP.
- ..this leaves the "colonel" task as a simple hlt idle loop.
- Mask all IRQs on startup (except IRQ2 for slave passthru)
- Fix underallocation bug in Task::allocateRegion().
- Remember how many times each Task has been scheduled.

The panel and scheduling banner are disabled until I get things
working nicely in the (brave) new Console world.
2018-10-22 11:15:16 +02:00
Andreas Kling
dd6706a1a1 Fix null deref in contextSwitch(). 2018-10-21 21:57:43 +02:00
Andreas Kling
46ff281695 Turn the syscall interrupt into a trap (by switching the gate type.)
This leaves interrupts enabled while we're in the kernel, which is
precisely what we want.

This uncovered a horrendous problem with kernel tasks silently
overflowing their stacks. For now I've simply increased the stack size
but I need a more MMU-y solution for this eventually.
2018-10-19 11:31:18 +02:00
Andreas Kling
3649638259 Add Regions concept to Task. 2018-10-18 14:55:20 +02:00
Andreas Kling
f67d695254 More paging stuff.
The test userspace process now runs at linear address 0x300000 which is
mapped to a dynamically allocated page from the MemoryManager. Cool!
2018-10-18 13:05:00 +02:00
Andreas Kling
89851a9ded Use FileHandle from VFS. 2018-10-18 10:28:09 +02:00
Andreas Kling
9d5de91cf3 Actually destroy tasks after they crash. 2018-10-18 00:26:30 +02:00
Andreas Kling
56c1f9db8e A userspace process can now GPF and the OS goes on!
This is really rickety, but it kinda sorta works for my test GPF!
2018-10-17 23:49:32 +02:00
Andreas Kling
77299cf54d Add basic paging. Only identity maps the bottom 4MB as a start. 2018-10-17 23:13:55 +02:00
Andreas Kling
9171521752 Integrate ext2 from VFS into Kernel. 2018-10-17 10:57:23 +02:00
Andreas Kling
72bb80a9ae These changes were lying around uncommitted in the old repo.
I'm just gonna commit them without too much thinking and then take
it from there.
2018-10-16 11:06:35 +02:00
Andreas Kling
9396108034 Import the "gerbert" kernel I worked on earlier this year.
It's a lot crappier than I remembered it. It's gonna need a lot of work.
2018-10-16 11:02:00 +02:00