Previously, this compiler flag was not being applied
regardless of CONFIG_SPIRAM_CACHE_WORKAROUND setting.
Explanation: add_compile_options() only applies to
source files added after the function is run, or in
subdirectories added after the function is run. In
this case, no new source files were being added after
this function was run.
When IDF_PATH is not set by the user, cmake infers the same through
other means and sets it as an environment variable. However, some
sub-invocation of cmake may not see this variable as it is not set
in the parent. This change adds a custom command for exporting IDF_PATH
just before invoking ldgen so that IDF_PATH can be used in Kconfig
without any errors.
Added a new structure esp_app_desc_t. It has info about firmware:
version, secure_version, project_name, time/date build and IDF version.
Added the ability to add a custom structure with a description of the firmware.
The esp_app_desc_t is located in fixed place in start of ROM secotor. It is located after structures esp_image_header_t and esp_image_segment_header_t.
app_version is filed from PROJECT_VER variable (if set in custom make file) or PROJECT_PATH/version.txt or git repo (git describe).
Add API to get app_desc from partition.
