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RTC.cpp
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RTC.cpp
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/*
* Copyright (c) 2018-2020, Andreas Kling <[email protected]>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Time.h>
#include <Kernel/Arch/x86/IO.h>
#include <Kernel/CMOS.h>
#include <Kernel/RTC.h>
namespace RTC {
static time_t s_boot_time;
void initialize()
{
s_boot_time = now();
}
time_t boot_time()
{
return s_boot_time;
}
static bool update_in_progress()
{
return CMOS::read(0x0a) & 0x80;
}
static u8 bcd_to_binary(u8 bcd)
{
return (bcd & 0x0F) + ((bcd >> 4) * 10);
}
static bool try_to_read_registers(unsigned& year, unsigned& month, unsigned& day, unsigned& hour, unsigned& minute, unsigned& second)
{
// Note: Let's wait 0.01 seconds until we stop trying to query the RTC CMOS
size_t time_passed_in_milliseconds = 0;
bool update_in_progress_ended_successfully = false;
while (time_passed_in_milliseconds < 100) {
if (!update_in_progress()) {
update_in_progress_ended_successfully = true;
break;
}
IO::delay(1000);
time_passed_in_milliseconds++;
}