We try to read twice from the RTC CMOS registers, and if the values are
not the same for 5 attempts, we know there's a malfunction with the
hardware so we declare these values as bogus in the kernel log.
When we try to query the time from the RTC CMOS, we try to check if
the CMOS is updated. If it is updated for a long period of time (as a
result of hardware malfunction), break the loop and return Unix epoch
time.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
The JS tests pointed out that the implementation in DateTime
had an off-by-one in the month when doing the leap year check,
so this change fixes that bug.
The CMOS sets bit 2 (0x4) if times are binary, if it's not
set they're in BCD.
The CMOS sets bit 1 (0x1) if hours are on a 12 hour clock.
In that case, the highest bit in the hour byte is set for
PM times (both in binary and BCD times).
Three bugs:
1. The lower 7 bits were masked off incorrectly when calling
bcd_to_binary(). Use 0x7F as mask, not 0x70.
2. The highest bit to check if a time was PM was checked after
BCD conversion of the low 7 bits, which clobbered that bit.
Do the check before BCD conversion.
3. In the 12 hour clock, midnight and noon are "12", so those
need to be converted to 0 even if for non-PM times (else
midnight is "12", not "0").
With this, SerenityOS consistently shows UTC as the current time,
as it should.
If folks want it to display local time instead, they can get this
by adding `-rtc base=localtime` to Meta/run.sh -- but a better fix
would be to add timezone management and convert from UTC system
clock to the user timezone at display time.
This enables a nice warning in case a function becomes dead code. Also, in case
of signal_trampoline_dummy, marking it external (non-static) prevents it from
being 'optimized away', which would lead to surprising and weird linker errors.
I found these places by using -Wmissing-declarations.
The Kernel still shows these issues, which I think are false-positives,
but don't want to touch:
- Kernel/Arch/i386/CPU.cpp:1081:17: void Kernel::enter_thread_context(Kernel::Thread*, Kernel::Thread*)
- Kernel/Arch/i386/CPU.cpp:1170:17: void Kernel::context_first_init(Kernel::Thread*, Kernel::Thread*, Kernel::TrapFrame*)
- Kernel/Arch/i386/CPU.cpp:1304:16: u32 Kernel::do_init_context(Kernel::Thread*, u32)
- Kernel/Arch/i386/CPU.cpp:1347:17: void Kernel::pre_init_finished()
- Kernel/Arch/i386/CPU.cpp:1360:17: void Kernel::post_init_finished()
No idea, not gonna touch it.
- Kernel/init.cpp:104:30: void Kernel::init()
- Kernel/init.cpp:167:30: void Kernel::init_ap(u32, Kernel::Processor*)
- Kernel/init.cpp:184:17: void Kernel::init_finished(u32)
Called by boot.S.
- Kernel/init.cpp:383:16: int Kernel::__cxa_atexit(void (*)(void*), void*, void*)
- Kernel/StdLib.cpp:285:19: void __cxa_pure_virtual()
- Kernel/StdLib.cpp:300:19: void __stack_chk_fail()
- Kernel/StdLib.cpp:305:19: void __stack_chk_fail_local()
Not sure how to tell the compiler that the compiler is already using them.
Also, maybe __cxa_atexit should go into StdLib.cpp?
- Kernel/Modules/TestModule.cpp:31:17: void module_init()
- Kernel/Modules/TestModule.cpp:40:17: void module_fini()
Could maybe go into a new header. This would also provide type-checking for new modules.
Also, duplicate data in dbg() and klog() calls were removed.
In addition, leakage of virtual address to kernel log is prevented.
This is done by replacing kprintf() calls to dbg() calls with the
leaked data instead.
Also, other kprintf() calls were replaced with klog().
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.
For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.
Going forward, all new source files should include a license header.
It turns out some BIOS vendors don't support non-BCD date/time mode, but
we were relying on it being available. We no longer do this, but instead
check whether the BIOS claims to provide BCD or regular binary values for
its date/time data.
