Sources:

• https://github.com/jcmvbkbc/esp-idf/tree/linux
• https://github.com/jcmvbkbc/linux-xtensa/tree/xtensa-5.18-esp32
• buildroot mainline

$ cd examples/get-started/linux_boot
$ idf.py build
$ idf.py -p /dev/ttyUSB0 flash
$ parttool.py -p /dev/ttyUSB0 write_partition --partition-name linux --input xip-esp32-esp32/arch/xtensa/boot/xipImage
$ parttool.py -p /dev/ttyUSB0 write_partition --partition-name rootfs --input build-xtensa-nommu-de108/images/rootfs.cramfs