Here is somethig you might find useful: automatic pio assembly -> h file generation for platformio.
I have tested it on Linux only.
This is the state as of Nov 2022. The arduino core for RP2040 will most likely change in the future and make this method obsolete.
Contrary to the docs, stating the pioasm is installed together with the dev platform:
https://registry.platformio.org/tools/earlephilhower/tool-pioasm-rp2040-earlephilhower/installation
the json file
https://github.com/maxgerhardt/platform-raspberrypi/blob/develop/platform.json