Fix bugs about role switch
Fix watchdog timeout when sleep enabled and crash without enabling sw coex
Fix ble crash issue triggered by ble event irq miss(0x20000)
Future events scheduling error in case of wifi and bluetooth.
* Linker was choosing ROM symbols for these, which use integer soft-float
operations and are much slower.
* _divsf3() moved to IRAM to avoid regressions with any code that does
integer float division in IRAM interrupt handlers (+88 bytes IRAM)
* Thanks to michal for reporting:
https://esp32.com/viewtopic.php?f=14&t=10540&p=43367
Removes the need to know/guess the paths to these libraries. Once we are gcc 8 only, we
can remove -nostdlib and no additional arguments are needed for system libraries.
The catch is: any time IDF overrides a symbol in the toolchain sysroot, we need
an undefined linker marker to make sure this symbol is seen by linker.
1. separate rom include files and linkscript to esp_rom
2. modefiy "include rom/xxx.h" to "include esp32/rom/xxx.h"
3. Forward compatible
4. update mqtt
