Bananymous
25c021c15b
Kernel: Add function to enumerate processes in session
2023-08-22 14:52:28 +03:00
Bananymous
42b90ae76c
Kernel/LibC: Add {get,set}pgrp()
2023-08-22 11:36:33 +03:00
Bananymous
ccc61cb10c
Kernel: Barebones implementation sessions and process groups
2023-08-22 11:35:40 +03:00
Bananymous
8e4216215e
Kernel/LibC: add dup() syscall and function
2023-08-17 12:03:29 +03:00
Bananymous
38c0bc7bae
Kernel: Remove unused syscall
2023-08-11 11:43:48 +03:00
Bananymous
a7f37236bf
Kernel: Zero initialize threads sse_storage
2023-08-11 00:26:43 +03:00
Bananymous
03d4b47f63
Kernel: HPET is now used in legacy mode when PIC is forced
2023-08-10 22:01:30 +03:00
Bananymous
e74fdbc55b
Kernel: Remove get_unix_timestamp from SystemTimer
...
Kernel now uses the percise real_time() and time_since_boot()
2023-08-09 08:57:50 +03:00
Bananymous
008c777a9f
Kernel: Add PageTable::Flags::CacheDisable
...
Also fix multiple places where we were using uint8_t as page table
flags instead of PageTable::flags_t which we promoted to uint16_t
while back.
2023-08-06 23:59:30 +03:00
Bananymous
d8a9d4a24e
Kerne: SystemTimer can now output the current real time
2023-08-04 16:06:47 +03:00
Bananymous
bc0e1fa898
Kernel: Rename TimerHandler to SystemTimer
...
I changed SystemTimer to only handle the "best" supported timer
it can initialize.
2023-08-04 16:06:47 +03:00
Bananymous
17f1737c9a
Kernel: Add function to retrieve boot time as timespec
2023-08-04 16:06:47 +03:00
Bananymous
fdae253695
Kernel: Add basic HPET support to replace PIT if exists
...
This works same way as the PIT implementation; calls Scheduler every
milli second.
2023-08-04 15:22:51 +03:00
Bananymous
d4adcff958
Kernel: Move sleep() implementation to TimerHandler
2023-08-04 15:15:00 +03:00
Bananymous
2c59c9a3cc
Kernel: Add more structures to ACPI
2023-08-04 15:13:47 +03:00
Bananymous
3a59a64355
Kernel: Implement basic MMIO functions
...
This is equivalent to IO.h except for memory mapped io instead of
IO ports
2023-08-04 15:12:29 +03:00
Bananymous
9363c1cdaf
Kernel: Move RTC to Timer directory
...
PIT ms counter seems to be off by multiple seconds/minute. I will
be probably changing to HPET for system time
2023-08-04 11:12:16 +03:00
Bananymous
198e6d7cf6
Kernel: Start work on abstracting Timers
2023-08-04 10:29:42 +03:00
Bananymous
07ee898f4f
Kernel: Remove unnecessary timer check from Scheduler
2023-08-04 10:29:42 +03:00
Bananymous
91f04ce250
Kernel: Change PageTable API
...
Getting free pages not reserves them, so you don't have to hold
the page table lock :)
2023-08-02 22:09:14 +03:00
Bananymous
926df2b276
Kernel: PageTable now supports reserved pages
...
You can now map pages as reserved, so that they will not be given
from get_free_page() or get_free_contiguous_pages().
2023-08-01 16:35:54 +03:00
Bananymous
217dbca7b7
Kernel: Cleanup returns from any kind on interrupts
2023-08-01 14:23:50 +03:00
Bananymous
8b1bccb79b
Kernel: store/load sse/mmx/fpu state on isr/irq/syscall
...
I haven't tested this yet but should be fine. This will be optimized
to only save state from threads that are using it
2023-07-31 22:28:57 +03:00
Bananymous
e86e755c51
Kernel: Generally improve signals
2023-07-31 22:28:18 +03:00
Bananymous
6f7d97cf94
Kernel: Remove is_in_syscall from Thread
2023-07-30 14:49:51 +03:00
Bananymous
879706e6e9
Kernel: Signals are not queued anymore
...
Posix doesn't require signal queing if you don't use sigqueue() which
we don't support. Process also has its own pending signal mask.
2023-07-29 16:54:31 +03:00
Bananymous
22cd9af8cc
Kernel: Restructure process and thread termination
...
When we want to kill a process, we mark its threads as Terminating
or Terminated. If the thread is in critical section that has to be
finished, it will be in Terminating state until done. Once Scheduler
is trying to execute Terminated thread it will instead delete it.
Once processes last thread is marked Terminated, the processes will
turn it into a cleanup thread, that will allow blocks and memory
cleanup to be done.
2023-07-28 18:06:20 +03:00
Bananymous
a9cf9bceef
Kernel: Rewrite DiskCache
...
We now cache only clean pages since I don't want to think about
syncing the disk later.
2023-07-27 22:22:39 +03:00
Bananymous
6c0f864a6e
Kernel: Locks allow locking after locker is invalid
...
SpinLock and RecursiveSpinLock will now allow locking after the initial
locker is invalid. This allows us to kill threads even if they are holding
internal locks
2023-07-27 18:52:51 +03:00
Bananymous
0f23e1f0f4
Kernel: Scheduler can now check if tid is valid
...
Tid can become invalid if the thread is already terminated
2023-07-27 18:34:06 +03:00
Bananymous
432c296b7b
Kernel: Implement SYS_GET_PID and SYS_TCSETPGID
...
we don't have consept of process groups yet
2023-07-24 22:29:59 +03:00
Bananymous
b576d373c4
Kernel: TTY now stores foreground process pid
...
this will be process pgid when we have process groups
2023-07-24 22:29:59 +03:00
Bananymous
522aa8e762
Kernel: add Thread::queue_signal()
2023-07-24 22:26:10 +03:00
Bananymous
146802fa4c
Kernel: Scheduler can now block threads based on tid
2023-07-24 22:24:21 +03:00
Bananymous
cc8af25d73
Kernel: remove Semaphore::is_blocked
...
this will not mean anything after semaphores can spuriously wake up
2023-07-24 22:23:13 +03:00
Bananymous
f5f4bf58ad
Kernel: add is_tty() to inode
2023-07-24 22:19:59 +03:00
Bananymous
3784da0d18
Kernel: you can now ask process if it is userspace process
2023-07-23 18:54:10 +03:00
Bananymous
9eb72f4392
Kernel: OpenFileDesctiptor can now return inode of fd
2023-07-23 18:52:33 +03:00
Bananymous
f7bf6d5e62
Kernel: Change signal kernel API
...
return rsp and rip are now stored per thread
2023-07-23 18:33:10 +03:00
Bananymous
adb14ba373
Kernel: Userspace signal handlers are now called one at a time
...
I added a syscall for telling the kernel when signal execution has
finished. We should send a random hash or id to the signal trampoline
that we would include in the syscall, so validity of signal exit can
be confirmed.
2023-07-23 13:34:53 +03:00
Bananymous
2149cec29f
Kernel: Make signals more POSIX
2023-07-21 20:01:12 +03:00
Bananymous
ad756c36fc
Kernel/LibC: Add SYS_KILL/kill()
2023-07-21 19:27:38 +03:00
Bananymous
b56316e9da
Kernel: Scheduler now sends queued signals
2023-07-21 19:27:10 +03:00
Bananymous
a989c44211
Kernel: Make signals thread specific
2023-07-21 19:00:59 +03:00
Bananymous
217e5f81cc
Kernel: add default signal actions
2023-07-21 18:02:35 +03:00
Bananymous
dcd4d0daeb
Kernel/LibC: Add bareboness signals
...
You can now call raise() to raise a signal. Signal handlers are
not yet supported, but the handling works :)
2023-07-21 15:45:02 +03:00
Bananymous
193ddaa2f6
Kernel: remove PAGE_FLAGS_MASK as that was not correct anymore
...
After I added NXE bit, the flags mask is no longer valid
2023-07-21 12:01:50 +03:00
Bananymous
2db7cdb71e
Kernel: Syscalls now get the interrupt stack
2023-07-21 11:04:16 +03:00
Bananymous
f8a1a10897
Kernel: add NullDevice to /dev/null
2023-07-20 00:06:22 +03:00
Bananymous
adbe13938e
Kernel: move Device.h to its own directory
2023-07-19 23:55:38 +03:00
Bananymous
98cedf155c
Kernel: FixedWidthAllocator creation can now fail
2023-07-19 18:07:24 +03:00
Bananymous
c0c0bbc1bf
Kernel: SYS_FORK can now fail instead of panicing on error
2023-07-19 17:47:12 +03:00
Bananymous
7d00c2670f
Kernel: Support execute disable bit
...
We will now map executable memory explicitly as executable.
2023-07-13 14:28:53 +03:00
Bananymous
bca7e9a1e8
Kernel: CPUID can detect wether cpu supports nxe bit
2023-07-13 14:24:58 +03:00
Bananymous
3748f0304f
Kernel: Fix multiple bugs with terminal
2023-07-13 13:09:52 +03:00
Bananymous
74c79c7eff
Kernel: Rewrite whole device structure
...
We now have DevFileSystem which is derived from RamFileSystem. All
devices are RamInodes. We don't have separate DeviceManager anymore.
To iterate over devices, you can loop througn every inode in devfs.
2023-07-10 23:17:14 +03:00
Bananymous
5a5656b2d3
Kenrel: RamInode now implements truncate()
2023-07-10 16:07:09 +03:00
Bananymous
1a1e584cba
Kernel: OpenFileDescriptors can now store more than 8 bits of flags
2023-07-10 16:06:36 +03:00
Bananymous
65fa05f998
Kernel: add O_TRUNC
...
this is not supported by anything yet
2023-07-10 15:48:18 +03:00
Bananymous
1e173c178d
Kernel: Ext2 fill now return ENOTSUP on write
...
We used to crash the kernel
2023-07-10 15:34:25 +03:00
Bananymous
4972284dde
Kernel: open() and openat() now take mode as parameter
...
O_CREAT now tries to create file if O_CREAT is specified
2023-07-10 15:08:54 +03:00
Bananymous
45789fda08
Kernel: You can now read/write to RamInodes
...
RamFS should be stored on physical pages and not in kmalloc, but
that will be implemented later :)
2023-07-10 14:09:35 +03:00
Bananymous
3b5bc63d1b
Kernel: Inode::create_file() now takes uid and gid as parameters
2023-07-10 13:32:10 +03:00
Bananymous
f1089e2b8a
Kernel: start work on ram file system
2023-07-10 13:26:14 +03:00
Bananymous
363c325c79
Kenrel: Fix inode comparison
...
We should not compare rdevs
2023-07-10 11:48:11 +03:00
Bananymous
583504ebe0
Kernel: Inode rename directory functions
2023-07-10 11:48:11 +03:00
Bananymous
b354b77f8b
Kernel: Mark Ext2 classes final
2023-07-10 11:48:11 +03:00
Bananymous
19dab08275
Kernel: add more functionality to PCI
2023-07-09 23:04:11 +03:00
Bananymous
78c091f7f8
Kernel: Move open file descriptors to their own class
...
This simplifies code a lot :)
2023-07-07 23:11:37 +03:00
Bananymous
a549336530
Kernel/LibC: add basic dup2
2023-07-06 23:17:54 +03:00
Bananymous
4eb95c963d
Kernel/LibC: Add basic pipe() syscall and command
...
You can now create pipes :)
2023-07-06 22:16:26 +03:00
Bananymous
3c068aa0ae
Kernel/LibC: add clock_gettime() for CLOCK_MONOTONIC
...
This gets the number of milliseconds since boot
2023-07-06 00:38:29 +03:00
Bananymous
86df258365
Kernel: rework the whole PageTable structure
...
We now have page table structure for kernel memory which is shared
between all processes.
2023-07-05 23:41:35 +03:00
Bananymous
0d620f3e0f
Kernel: Rewrite and optimize DiskCache
...
DiskCache now consists of PageCaches which are caches of contiguous
sectors. This allows the disk cache to be ordered and faster traversal.
We seem to have a problem somewhere during reading. The stack gets
corrupted.
2023-06-19 10:31:47 +03:00
Bananymous
5e123031aa
Kernel: kmalloc has now somewhat dynamic storage
...
Allocations bigger than PAGE_SIZE and those not forced to be identity
mapped are now done on a GeneralAllocator. This allows us to use kmalloc
for big allocations; bigger than the fixed 1 MiB storage.
This is still a hack and the whole kmalloc will have to be rewritten at
some point, but for now this does the job :D
2023-06-18 23:27:00 +03:00
Bananymous
388f530edd
Kernel: Add GeneralAllocator::paddr_of
...
Yoy can now query physical address of a virtual address for general
allocator allocation
2023-06-18 23:25:51 +03:00
Bananymous
714305ef56
Kernel: General allocator takes first valid vaddr as parameter
2023-06-17 22:23:34 +03:00
Bananymous
32e1473c94
Kernel: Make disk IO blocking thread safe
...
This was causing a lot of deadlocks on vms without kvm accel
2023-06-12 18:57:47 +03:00
Bananymous
bf617036c7
Kernel: Rework syscall calling
...
I removed the intermediate function when calling syscalls. Now syscall
handler calls the current process automatically. Only exception is
sys_fork, since it needs a assembly trampoline for the new thread.
2023-06-12 14:16:48 +03:00
Bananymous
ce55422a24
Kernel: Remove Shell from kernel
...
This is now obsolete since we have a userspace Shell.
2023-06-12 02:04:52 +03:00
Bananymous
0f63cfa43f
Kernel/LibC: add SYS_{SET,GET}_PWD and chdir, getpwd
2023-06-12 02:02:52 +03:00
Bananymous
b254ade69b
Kernel: Add SYS_GET_{,E}{UID,GID}
2023-06-11 22:37:00 +03:00
Bananymous
ef4ebaa969
Kernel: Add syscalls for set{,e,re}{uid,gid}
2023-06-11 22:37:00 +03:00
Bananymous
c62e820bcf
Kernel: Add basic Credentials for the system
...
Now filesystem access/open, etc confirm that you have access for rwxs
2023-06-11 20:06:06 +03:00
Bananymous
5aed186827
Kernel: Add SYS_OPENAT
2023-06-11 03:29:22 +03:00
Bananymous
e209ca7c82
Kernel: Rewrite directory listing so it can be integrated to libc
2023-06-11 00:17:18 +03:00
Bananymous
db49cbd6e2
Kernel: We now store the processes exit code
2023-06-10 17:31:56 +03:00
Bananymous
27cef23823
Kernel: Scheduler now has reschedule()
...
This can be called from anywhere and just causes the scheduler to
schedule the next thread. This is more efficient and verbose version
of Scheduler::set_current_thread_sleeping(0), since we don't have
to wake other threads or do other verifications.
2023-06-09 00:47:17 +03:00
Bananymous
b7fc2dc3d0
Kenrel: Rename Scheduler::reschedule -> Scheduler::timer_reschedule
2023-06-09 00:41:43 +03:00
Bananymous
8af390e0f6
Kernel: Big commit. Rewrite ELF loading code
...
We now load ELF files to VirtualRanges instead of using kmalloc.
We have only a fixed 1 MiB kmalloc for big allocations and this
allows loading files even when they don't fit in there.
This caused me to rewrite the whole ELF loading process since the
loaded ELF is not in memory mapped by every process.
Virtual ranges allow you to zero out the memory and to copy into
them from arbitary byte buffers.
2023-06-09 00:37:43 +03:00
Bananymous
96d6453ea8
Kernel: PageTableScope locks the PageTable before disabling interrupts
...
This allows replacing some PageTableScopes with PageTable::lock()
2023-06-09 00:34:41 +03:00
Bananymous
86f58f60cb
LibC: implement setenv, unsetenv, putenv
2023-06-05 22:51:02 +03:00
Bananymous
064ce568c2
Kernel: add basic support for environment variables
...
exec functions will search files from PATH
2023-06-05 22:51:02 +03:00
Bananymous
0b1b4d8f7e
Kernel: exec now has better posix errors
2023-06-05 21:12:08 +03:00
Bananymous
b0e9ab0519
Kernel/LibC: pass environ pointer to process
2023-06-05 21:12:08 +03:00
Bananymous
5425394880
Kernel: TTY now supports CSI s and u
...
These are commonly supported values to save and load cursor
position
2023-06-05 18:19:13 +03:00
Bananymous
9d64dbd5c2
Kernel/LibC: add SYS_STAT and stat(), lstat()
2023-06-05 14:37:14 +03:00
Bananymous
b68d5a5833
Kernel: Add SYS_WAIT
...
This syscall waits for a given pid.
2023-06-04 18:00:52 +03:00
Bananymous
924fc2118c
Kernel: Allocators are now stored in UniqPtr
...
This allows proper memory management, we had some memory leak
2023-06-04 01:25:57 +03:00
Bananymous
51f4c0c750
Kernel: make load_elf() its own function
2023-06-04 01:24:11 +03:00
Bananymous
37b93da650
Kernel: PhysicalRange maps its nodes to kernel vaddr space
...
This keeps the lower half of address space cleaner
2023-06-04 01:20:47 +03:00
Bananymous
8352392b38
Kernel: You can specify first vaddr for getting free pages
2023-06-04 01:15:48 +03:00
Bananymous
dc1aff58ed
Kernel: PAGE_FLAG_MASK is now only 0xF
...
We don't care currenly about anything but the last few bits
2023-06-03 20:08:13 +03:00
Bananymous
9f75d9cfe5
Kernel: PageTable now has debug_dump
...
This dumps all the mapped pages and their flags
2023-06-03 20:08:13 +03:00
Bananymous
a4cb5d8360
Kernel: Inode/Device detection is done with overridden bool functions
2023-06-03 13:28:15 +03:00
Bananymous
59b807189f
Kernel: add basic disk cache
...
ATADevices now add disk cache to themselves
2023-06-03 02:23:14 +03:00
Bananymous
fb1c7015b1
Kernel: Shell 'memory' now prints heap memory usage
2023-06-03 02:22:18 +03:00
Bananymous
4d4d0e26a9
Kernel: Symlinks are now working
...
We still have to implement loop or depth detection
2023-06-02 11:43:46 +03:00
Bananymous
232fdcb82c
Kernel: add basic support for symlinks
2023-06-01 00:24:45 +03:00
Bananymous
4da1d6fd27
Kernel: Implement Process::exec()
2023-05-31 20:56:29 +03:00
Bananymous
909e847369
Kernel: Move userspace entry functions to Process instead of Thread
2023-05-31 19:31:10 +03:00
Bananymous
ed0dcacab3
Kernel: Move V2P and P2V to Memory/Types.h
2023-05-30 23:57:03 +03:00
Bananymous
57f7da6ce1
Kernel: Booting with higher half kernel gets to Heap initialization
2023-05-30 22:21:12 +03:00
Bananymous
e640344d7a
Kernel: Rename MMU to PageTable
...
This is more descriptive name for what it actually represents
2023-05-29 21:06:09 +03:00
Bananymous
7151bb86a8
Kernel/LibC: opening standard files is done in libc
2023-05-29 20:21:19 +03:00
Bananymous
dd3f34cb2c
Kernel: Make RecursiveSpinLock thread safe
...
also SpinLock is now implemented with gcc builtins
2023-05-29 19:38:09 +03:00
Bananymous
282bf24f65
Kernel: fork() now copies allocations through FixedWidthAllocator
2023-05-28 21:34:35 +03:00
Bananymous
f964f6be8d
Kernel: Move page macros to Types.h
2023-05-28 21:03:08 +03:00
Bananymous
0202ccec5f
Kernel: ISR will now crash userspace process instead of panicing kernel
2023-05-28 20:53:10 +03:00
Bananymous
636c308993
Kernel: fork() now copies allocation done through GeneralAllocator
2023-05-28 20:37:39 +03:00
Bananymous
6fdbe6f9c2
Kernel: Add bareboness fork() function
2023-05-28 18:08:49 +03:00
Bananymous
c19f4c019a
Kernel: Add invalidate() to MMU
2023-05-28 18:05:49 +03:00
Bananymous
0129619d9a
Kernel: Processes and Threads use VirtualRange memory allocations
2023-05-28 17:48:34 +03:00
Bananymous
e0479b291d
Kernel: Move PhysicalRange to its own file and add VirtualRange
2023-05-28 17:48:34 +03:00
Bananymous
b847d7dfd5
Kernel: MMU::get() is now MMU::kernel
...
MMU is can now be locked with RecursiveSpinLock.
Scheduler now has get_current_tid() that works before the Scheduler
is initialized. This allows RecursiveSpinLock usage early on.
2023-05-28 16:18:18 +03:00
Bananymous
f79250c4d4
LibC: Rewrite all the headers.
...
We now have more or less posix issue 2018 conforming libc headers.
This was a really time consuming and boring operation but it had to
be done.
Now we get to actually start implementing libc :)
2023-05-26 22:31:21 +03:00
Bananymous
9e0abbc2f0
Kernel: Add bareboness possibility to set termios
2023-05-26 22:31:21 +03:00
Bananymous
4a4a3bf184
Kernel/LibC: move file offset back to kernel
...
This makes keeping track of offsets easier and more proper
2023-05-26 22:31:21 +03:00
Bananymous
f33e78882e
Kernel: Add argc and argv to process entry
2023-05-16 00:27:49 +03:00
Bananymous
0ff067bdb7
Kernel: Add MMUScope
...
This disables interrupts and loads specified mmu for the
scope it lives in
2023-05-16 00:26:39 +03:00
Bananymous
31ac3260ed
Kernel: MMU keeps track of the current
2023-05-16 00:26:39 +03:00
Bananymous
53f4b5a9da
LibC: add function declarations to sys/stat.h
2023-05-11 15:11:33 +03:00
Bananymous
1cf7ef3de6
Kernel: Remove offset from OpenFileDescriptor
...
This is now handled on the libc side. There might be reasons to
have it in kernel side, but for simplicity's sake I'm moving it
to libc for now :)
2023-05-09 20:31:22 +03:00
Bananymous
812e61ca70
Kernel: Add barebones GeneralAllocator for >4096B
2023-05-08 22:10:49 +03:00
Bananymous
2d0a5a9e15
Kernel: FixedWidthAllocator operates on MMU
...
Instead of Process* we use MMU& in FixedWidthAllocator since it is
everything it actually needs :)
2023-05-08 00:06:56 +03:00
Bananymous
f32d594879
Kernel: We add FixedWidthAllocators on demand
...
On SYS_ALLOC we will add a new FixedWidthAllocator if the old ones
are already full or we don't have one with proper size. This allows
arbitary number of allocations as long as you have enough memory
available :)
Next I will be writing a general allocator for allocations larger
than 4096 bytes which should make SYS_ALLOC syscall complete :)
2023-05-07 23:57:01 +03:00
Bananymous
2fe9af7165
Kernel/LibC: add free function for FixedWidthAllocator
...
I have to rework the syscall API and allocators in process. For
now this works well enough :)
2023-05-07 01:21:50 +03:00
Bananymous
ff5bcd4416
Kernel: Add basic fixed width allocator for userspace
...
We have to move process stacks to the general heap and maybe map
kernel to higher half.
2023-05-06 19:58:08 +03:00
Bananymous
b65cd1d09b
Kernel: Invalid physical addresses from heap are specified now by 0
2023-05-06 17:34:22 +03:00
Bananymous
06bc807e34
Kernel: MMU can now provide info about virtual address space
2023-05-06 17:34:22 +03:00
Bananymous
0cb53efa01
Kernel: 64 bit MMU now properly identity maps kernel
2023-05-05 14:19:28 +03:00
Bananymous
f139fc2229
Kernel: namespace and function renames
...
MMU moved to namespace kernel
Kernel::Memory::Heap moved to just Kernel
MMU::map_{page,range} renamed to identity_map_{page,range}
Add MMU::get_page_flags
2023-04-28 14:48:38 +03:00
Bananymous
58ce907327
Kernel: Usespace threads now have an interrupt stack
2023-04-25 14:49:18 +03:00
Bananymous
6ecc8cac0e
Kernel: TSS stack can be set after initialization
2023-04-25 14:48:12 +03:00
Bananymous
bd95f17426
Kernel: Stack pointer out of bounds now panics with a message
2023-04-25 13:40:55 +03:00
Bananymous
b15deb420f
LibC: Write mostly functioning stdio
2023-04-23 14:32:37 +03:00
Bananymous
8a5608df91
Kernel: d{print,warn,error}ln(...) now has a spinlock
2023-04-22 17:58:51 +03:00
Bananymous
3f1c0ec91b
Kernel: Process now frees up its pages on destruction
2023-04-22 16:54:46 +03:00
Bananymous
1406a75a92
Kernel: Cleanup process creation for userspace
2023-04-22 16:51:50 +03:00
Bananymous
ec8b9640e2
Kernel: Usespace programs are now ran through ELF files
...
only 64 bit elf files are supported for now.
2023-04-22 15:35:32 +03:00