This change fixes NuttX’s CMake support when NuttX is embedded
in another project via add_subdirectory(). CMake’s CMAKE_SOURCE_DIR
and CMAKE_BINARY_DIR refer to the outermost project, causing NuttX
to access its .config, generated files, host tools, and build artifacts
in the parent project’s directories. The fix introduces NUTTX_DIR and
NUTTX_BINARY_DIR, based on CMAKE_CURRENT_SOURCE_DIR and
CMAKE_CURRENT_BINARY_DIR, and consistently uses them for NuttX
self-references while preserving existing standalone builds. It fixes
the Kconfig initialization failure reported in #19697 and allows an
embedded sim:nsh build to configure, build, and boot successfully.
The change affects only the CMake build system (not Make or Kconfig
defaults), requires the corresponding nuttx-apps change, and does not
extend add_subdirectory() support to cross-compiled non-sim boards due
to CMake’s toolchain-file limitation.
Fixes#19697.
Assisted-by: Claude:claude-sonnet-5
Signed-off-by: Alan Carvalho de Assis <acassis@gmail.com>
