TinyUF2 is an open source cross-platform UF2 bootloader based on the TinyUSB library.
Checkout the code and sync submodules:
$ git clone https://github.com/arturo182/tinyuf2.git
$ cd tinyuf2
$ git submodule update --init --recursive
Specify the board you want to build for:
$ make BOARD=mimxrt1010_evk