pal_time.h File Reference

Initializes the time module.

After boot, the time in RAM will be initialized with the higher value of RTC and SOTP `SAVED_TIME`. If no RTC is present, RTC time is zero. After initialization, the time module will start counting ticks.

Returns:

PAL_SUCCESS when initialization succeeds.

Definition at line 24 of file pal_time.c.

Get the system time.

The time is calculated by the sum of the initial value + the number of ticks passed, converted into seconds.

Returns:

A 64-bit counter indicating the current system time in seconds on success.

Zero value when the time is not set in the system.

Note:

If the delta between the secure time value previously set in the system and the current system time is greater than `PAL_LAST_SAVED_TIME_LATENCY_SEC`, then the secure time value will be overwritten with the current system time.

Definition at line 31 of file pal_time.c.

Set the strong time. This function will be called when receiving time from a server that is completely trusted.

Set the time in RAM unconditionally. Save the new time in SOTP or RTC under the following conditions:

Time forward – if time difference between current time in SOTP (not device time) and new time is greater than a day.

Time backward – if time difference between current time and new time is greater than one minute. If the time is saved in SOTP (forward or backwards), the record `LAST_TIME_BACK` must be saved.

Parameters:

[in]

setTimeInSeconds

Seconds from January 1st 1970 UTC+0.

Returns:

PAL_SUCCESS when set strong succeed.

Note:

The limitations are aimed to reduce the number of write operations to the SOTP and not related to security.

Definition at line 45 of file pal_time.c.

Set the current system time, defined as seconds since January 1st 1970 UTC+0.

Parameters:

[in]

seconds

Seconds from January 1st 1970 UTC+0.

Returns:

PAL_SUCCESS when the time is set successfully.

PAL_ERR_INVALID_TIME when there is a failure in setting the system time.

Definition at line 38 of file pal_time.c.

Set the weak time.

Time Forward (a)
set the time (in RAM) unconditionally. Save the new time in SOTP if the change (between new time and current time in RAM) is greater than 24 hours. Set the time to RTC if the change is greater than 100 seconds. This limitation is to avoid multiple writes to the SOTP and RTC and not related to security.

Time Forward (b)
If (a) did not happen, save the time into SOTP if new time is greater from SAVED_TIME by a week (604800 seconds).

Time Backwards
set the device time on the device (RAM) and save the time in SOTP only if the change (between new time and current time in RAM) is smaller than 3 minutes for each day lapsed from the last change done via `pal_osSetWeakTime`. RTC is never set backwards by `pal_osSetWeakTime`.

Parameters:

[in]

setTimeInSeconds

Seconds from January 1st 1970 UTC+0.

Returns:

PAL_SUCCESS when set weak time is successful.

Note:

To implement this, when the new time is saved in SOTP by `pal_osSetWeakTime` two different records must be saved in SOTP:

1. The new time (the same record as in factory setup)

2. The time this action was performed, in order to enforce the 24 hours limitation. Record `LAST_TIME_BACK`.

Definition at line 52 of file pal_time.c.