The commit fixes the case:
If variables in RTC RAM have been moved around by the linker,
they will be filled with garbage data. Any reset other than OTA would work fine
because the variables would still be initialized from the initial bootup.
So now system time will be valid even after OTA.
Closes https://github.com/espressif/esp-idf/issues/9448
esp_light_sleep_start() will stall the other CPU via esp_ipc_isr_stall_other_cpu(). After stalling the other CPU,
will call esp_clk_... API which themselves take locks. If the other stalled CPU is holding those locks, this will
result in a deadlock.
This commit adds a workaround calling esp_clk_private_lock() to take the lock before stalling the other CPU.
esp_clk used to be protected using _lock_t (i.e., a FreeRTOS Mutex). However, esp_clk API is current called from
from critical sections, thus mutex should not be used (as they can be blocking).
This commit updates esp_clk to use spinlocks for critical sections instead.
1. Clean up clk usage in IDF, replace rtc_clk_xtal/apb_freq_get with
upper level API esp_clk_xtal/apb_freq
2. Fix small errors and wrong comments related to clock
3. Add clk_tree_defs.h to provide an unified clock id for each chip
Modify the NGed drivers to adopt new clock ids
