This function speeds up or slows down the system clock in order to make a gradual adjustment. This ensures
that the calendar time reported by the system clock is always monotonically increasing, which might not happen
if you simply set the clock.
The delta argument specifies a relative adjustment to be made to the clock time. If negative, the system clock is
slowed down for a while until it has lost this much elapsed time. If positive, the system clock is speeded up for a
while.
If the olddelta argument is not a null pointer, the adjtime function returns information about any previous time
adjustment that has not yet completed.
The return value is 0 on success and -1 on failure.
To stop the adjustement, call the function settimeofday(current_time).
* Philosophical: "explicit is better than implicit".
* Practical: Allows useful errors if invalid directories given in components as the defaults aren't
always used. Also trims the -I path from a number of components that have no actual include
directory.
* Simplifies knowing which components will be header-only and which won't
libc time function now rely on esp_timer_get_time as the source of
high-resolution time, rather than FRC1 timer. Internally, on the ESP32
esp_timer implementation uses FRC2 timer.
- Change help text and labels in Kconfig to use "high-resolution timer"
instead of FRC1. Keep existing Kconfig option name to be backwards
compatible.
- Change references to "FRC1" in the source code to "FRC".
These functions were discarded but not provided in ROM.
Generated from commit 8ad0aa7d6 in newlib script repo. Didn't rebuild most of libc/libc_nano,
only appended the missing object files to the existing archives (should save some git churn).
Allows fcntl() implementation in vfs to be used.
Closes https://github.com/espressif/esp-idf/issues/1070
Note this is different to the other libc file-related syscalls, as there is no
reent structure involved.
Fix warnings where undefined vars are used.
Make Kconfig emit "FOO=" for unset bool options
To ensure make variables are always defined, even if empty.
When writing auto.conf, include symbols disabled by dependency to make sure all make variables are always defined.
Fixesespressif/esp-idf#137
Cherry-picked from https://github.com/espressif/esp-idf/pull/138
For config-only components, component.mk should now contain "COMPONENT_CONFIG_ONLY := 1"
Also refactored some of the generation of linker paths, library list. This required cleaning up the way the bootloader
project works, it's now mostly independent from the parent.
If scheduler was running, and lock was an automatic variable (ie stack-allocated) to be initialised by _lock_init*,
initialisation could be skipped if the lock variable was non-zero (and lock would be left invalid).
In other cases the lock is statically initialised to zero by __LOCK_INIT*
Small changes to clock calibration value will cause increasing errors
the longer the device runs. Consider the case of deep sleep, assuming
that RTC counter is used for timekeeping:
- before sleep:
time_before = rtc_counter * calibration_val
- after sleep:
time_after = (rtc_counter + sleep_count) * (calibration_val + epsilon)
where 'epsilon' is a small estimation error of 'calibration_val'.
The apparent sleep duration thus will be:
time_after - time_before = sleep_count * (calibration_val + epsilon)
+ rtc_counter * epsilon
Second term on the right hand side is the error in time difference
estimation, it is proportional to the total system runtime (rtc_counter).
To avoid this issue, this change makes RTC_SLOW_CLK calibration value
persistent across restarts. This allows the calibration value update to
be preformed, while keeping time after update same as before the update.
This change removes the erroneous cast to uint32_t (which caused time to
wrap around after 1 hour) and splits the multiplication into two terms
to remove the wraparound after 13 days.
Ref. https://esp32.com/viewtopic.php?f=13&t=1908
- RTC_CNTL_SLOWCLK_FREQ define is removed; rtc_clk_slow_freq_get_hz
function can be used instead to get an approximate RTC_SLOW_CLK
frequency
- Clock calibration is performed at startup. The value is saved and used
for timekeeping and when entering deep sleep.
- When using the 32k XTAL, startup code will wait for the oscillator to
start up. This can be possibly optimized by starting a separate task
to wait for oscillator startup, and performing clock switch in that
task.
- Fix a bug that 32k XTAL would be disabled in rtc_clk_init.
- Fix a rounding error in rtc_clk_cal, which caused systematic frequency
error.
- Fix an overflow bug which caused rtc_clk_cal to timeout early if the
slow_clk_cycles argument would exceed certain value
- Improve 32k XTAL oscillator startup time by introducing bootstrapping
code, which uses internal pullup/pulldown resistors on 32K_N/32K_P
pins to set better initial conditions for the oscillator.
