esp-idf/components/esp_system
morris be9d294718 Merge branch 'contrib/github_pr_10027_v4.4' into 'release/v4.4'
[Panic] also print to secondary USB Serial/JTAG Console (GitHub PR) (v4.4)

See merge request espressif/esp-idf!21022
2022-11-18 11:52:06 +08:00
..
include
ld (Xtensa) Build: add .xt.prop and .xt.lit to the compiled ELF file 2022-08-17 14:58:36 +08:00
port wifi/bt: fix part of modem module not reset when power up 2022-11-10 16:00:02 +08:00
test
test_apps ulp-riscv: add support for using ADC as well as an example show-casing it. 2022-08-09 09:21:15 +08:00
test_eh_frame_parser
CMakeLists.txt
Kconfig
Makefile.projbuild
README.md
app.lf
component.mk
crosscore_int.c
debug_stubs.c
eh_frame_parser.c
esp_err.c
esp_system.c
fpga_overrides.c
freertos_hooks.c
int_wdt.c
linker.lf
panic.c [Panic] also print to secondary USB Serial/JTAG Console 2022-11-09 23:54:44 +01:00
sdkconfig.rename
stack_check.c
startup.c newlib: Add workaround for printf functions using 32-bit time_t on first call 2022-08-22 11:56:51 +08:00
system_time.c
task_wdt.c
ubsan.c
xt_wdt.c

README.md

System Notes

Timekeeping

The following are the timekeeping mechanisms available and their differences:

  1. System time (esp_system_get_time)

Time with the origin at g_startup_time. The implementation is not handled by esp_system, but it does provide a default implementation using RTC timer. Currently, esp_timer provides system time, since the hardware timers are under the control of that component. However, no matter the underlying timer, the system time provider should maintain the definition of having the origin point at g_startup_time.

  1. esp_timer time (esp_timer_get_time)

This is the time read from an underlying hardware timer, controlled through config. Origin is at the point where the underlying timer starts counting.

  1. newlib time (gettimeofday)

Timekeeping function in standard library. Can be set (settimeofday) or moved forward/backward (adjtime); with the possibility of the changes being made persistent through config. Currently implemented in terms of system time, as the point of origin is fixed. If persistence is enabled, RTC time is also used in conjuction with system time.

  1. RTC time (esp_rtc_get_time_us)

Time read from RTC timer.