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.
Each COMPONENT_DIRS directory can now either be a component directory, or a parent directory containing component
subdirectories.
When searching for components, skip any directory which doesn't have component.mk, Kconfig.projbuild, or
Makefile.projbuild in it. This helps with debugging, list-components output, etc.
Implements support for system level traces compatible with SEGGER
SystemView tool on top of ESP32 application tracing module.
That kind of traces can help to analyse program's behaviour.
SystemView can show timeline of tasks/ISRs execution, context switches,
statistics related to the CPUs' load distribution etc.
Also this commit adds useful feature to ESP32 application tracing module:
- Trace data buffering is implemented to handle temporary peaks of events load
