add timestampts to logger

[ChillerDragon]

No description provided.

[ChillerDragon]

Seems like the linux kernel only offers syscalls to get the timezone or epoch. So we would have to convert that to year/month/day which is not that straightforward. I yoinked the musl libc code without safety checks and timezone into a sample program that works.

#include <stdio.h>
#include <time.h>

#define LEAPOCH (946684800LL + 86400*(31+29))

#define DAYS_PER_400Y (365*400 + 97)
#define DAYS_PER_100Y (365*100 + 24)
#define DAYS_PER_4Y   (365*4   + 1)

int __secs_to_tm(long long t, struct tm *tm)
{
	long long days, secs, years;
	int remdays, remsecs, remyears;
	int qc_cycles, c_cycles, q_cycles;
	int months;
	int wday, yday, leap;
	static const char days_in_month[] = {31,30,31,30,31,31,30,31,30,31,31,29};

	secs = t - LEAPOCH;
	days = secs / 86400;
	remsecs = secs % 86400;
	if (remsecs < 0) {
		remsecs += 86400;
		days--;
	}

	wday = (3+days)%7;
	if (wday < 0) wday += 7;

	qc_cycles = days / DAYS_PER_400Y;
	remdays = days % DAYS_PER_400Y;
	if (remdays < 0) {
		remdays += DAYS_PER_400Y;
		qc_cycles--;
	}

	c_cycles = remdays / DAYS_PER_100Y;
	if (c_cycles == 4) c_cycles--;
	remdays -= c_cycles * DAYS_PER_100Y;

	q_cycles = remdays / DAYS_PER_4Y;
	if (q_cycles == 25) q_cycles--;
	remdays -= q_cycles * DAYS_PER_4Y;

	remyears = remdays / 365;
	if (remyears == 4) remyears--;
	remdays -= remyears * 365;

	leap = !remyears && (q_cycles || !c_cycles);
	yday = remdays + 31 + 28 + leap;
	if (yday >= 365+leap) yday -= 365+leap;

	years = remyears + 4*q_cycles + 100*c_cycles + 400LL*qc_cycles;

	for (months=0; days_in_month[months] <= remdays; months++)
		remdays -= days_in_month[months];

	if (months >= 10) {
		months -= 12;
		years++;
	}

	tm->tm_year = years + 100;
	tm->tm_mon = months + 2;
	tm->tm_mday = remdays + 1;
	tm->tm_wday = wday;
	tm->tm_yday = yday;

	tm->tm_hour = remsecs / 3600;
	tm->tm_min = remsecs / 60 % 60;
	tm->tm_sec = remsecs % 60;

	return 0;
}

int main() {
    struct tm dt = {};
    __secs_to_tm(1734062161, &dt);
    printf("year=%d\n", dt.tm_year + 1900);
}

So porting that to assembly should do. But that would be a lot of effort and would need lots of unit tests.
I think for now lets just use the epoch as timestamp in the logger. And if someone really needs to know the date after the fact they can do the conversion them self.