Multiple partitions, one at a time. Coped from SPIFFS implementation. https://github.com/espressif/arduino-esp32/commit/3cbfa2ffef2e9808310207ae791571b2ff13c85e#diff-d033864b5ea50ef1ee43c07dfc1ec7c828f4eff57dee791348fd66e6d588ac78 See LITTLEFS_test example