During the past weeks i’ve worked on getting the FOTA upgrades work on the 2MB boards by Olimex. The wonderful esp-link project by Thorsten von Eicken was a great example of two things: How to concatenate the espfs filesystem image with the firmware images. How to properly write a new image to the flash. It was a nice example to start with. So after a lot of fiddling with Makefiles, cgi routines and esptool – i’ve finally got the OTA working.
Which goes where – when using a bootloader for FOTA. The files: master_device_key.bin – Obtained from Espressif Cloud esp_init_data_default.bin – Stores default RF parameter values boot.bin – bootloader user1.bin and user2.bin – user firmware blank.bin – blank settings , flash to get default parameters 512KB master_device_key.bin 0x3E000 esp_init_data_default.bin 0x7C000 blank.bin 0x7E000 boot.bin 0x00000 user1.bin 0x01000 user2.bin 0x41000 1024KB Flash master_device_key.bin 0x3E000 esp_init_data_default.bin 0xFC000 blank.bin 0xFE000 boot.