ESP32: How do I use a custom CMakeLists.txt file?

[Reverse chronological order]


Okay, I fixed the Two environments problem by moving the entire esp_loader to a new top-level directory name external', and updating the top-level CMakeLists.txt` thusly:

I suspect the Two environments issue is because the CMakeLists.txt in src performs a recursive file glob, and some of the same files are also added by the CMakeLists.txt in esp_loader.

cmake_minimum_required(VERSION 3.16.0)
list(APPEND EXTRA_COMPONENT_DIRS external/esp_loader)


I fixed this by adding

list( APPENDEXTRA_COMPONENT_DIRS src/updater/esp_loader)

to the top level CMakelists.txt, but now I get:

*** Two environments with different actions were specified for the same target: <REDACTED>/firmware/.pio/build/esp32dev/src/updater/esp_loader/src/esp_loader.o

Original problem below

I have some code in a sub directory that has a simple CMakeLists.txt file:

cmake_minimum_required(VERSION 3.5)


idf_component_register(SRCS ${srcs}
    INCLUDE_DIRS include port
    PRIV_INCLUDE_DIRS private_include
    PRIV_REQUIRES driver esp_timer)

How can I have PIO honor this CMakeLists.txt file?

The build fails because the include paths are wrong; I could just change the code, but it’s external code, and I’d rather keep the structure as-is.

I suspect, but I’m not sure that it’s okay to have a sub-directory CMakeLists.txt like this within the IDF, but that implies it would be explicitly included by a higher-level CMakeLists.txt, but with PIO, the CMakeLists.txt is generated …

Also, I added a FATAL_ERROR to the CMakeLists.txt, and it does not abort, so I know it’s not reading it.

Errors specifically like this:

Compiling .pio/build/esp32dev/src/updater/esp_loader/src/protocol_common.o
src/updater/esp_loader/src/esp_targets.c:16:10: fatal error: esp_targets.h: No such file or directory
   16 | #include "esp_targets.h"
      |          ^~~~~~~~~~~~~~~
compilation terminated.

Directory structure:

├── CMakeLists.txt
├── include
│   ├── esp_loader.h
│   ├── esp_loader_io.h
│   └── serial_io.h
├── private_include
│   ├── esp_targets.h
│   ├── md5_hash.h
│   ├── protocol.h
│   ├── protocol_prv.h
│   └── slip.h
└── src
    ├── esp32_port.c
    ├── esp32_port.h
    ├── esp_loader.c
    ├── esp_targets.c
    ├── md5_hash.c
    ├── protocol_common.c
    ├── protocol_spi.c
    ├── protocol_uart.c
    └── slip.c