In addition, the following configuration options control the reset condition:ĬONFIG_BOOTLOADER_NUM_PIN_FACTORY_RESET- The input GPIO number used to trigger a factory reset. The “factory” app partition slot (if it exists) is never updated via OTA, so resetting to this allows reverting to a “known good” firmware application.Įither or both of these configuration options can be enabled independently. This reset process involves erasing the OTA data partition which holds the currently selected OTA partition slot. Enabling the CONFIG_BOOTLOADER_OTA_DATA_ERASE option will cause the device to boot from the default “factory” app partition after a factory reset (or if there is no factory app partition in the partition table then the default ota app partition is selected instead). Partitions of type “app” cannot be specified here.īoot from “factory” app partition. Make sure that the names of partitions specified in the option are the same as those found in the partition table. Users can specify the names of partitions as a comma-delimited list with optional spaces for readability. The CONFIG_BOOTLOADER_DATA_FACTORY_RESET option allows users to specify which data partitions will be erased when the factory reset is executed. The factory reset mechanism allows the device to be factory reset in two ways:Ĭlear one or more data partitions. To roll back to the original “factory” device configuration and clear any user settings, configure the config item CONFIG_BOOTLOADER_FACTORY_RESET in the bootloader. Sometimes it is desirable to have a way for the device to fall back to a known-good state, in case of some problem with an update. To maintain compatibility with older bootloaders, the app re-initializes the flash settings during app startup using the configuration found in the app header.

This allows an OTA update to change the SPI flash settings in use.īootloaders prior to ESP-IDF V4.0 used the bootloader’s own header to configure the SPI flash, meaning these values could not be changed in an update. When the Second stage bootloader then runs, it will reconfigure the flash using values read from the currently selected app binary’s header (and NOT from the Second stage bootloader header). However, at this time the system clock speed is lower than configured and not all flash modes are supported.

The First stage bootloader in ROM reads the Second stage bootloader header information from flash and uses this infomation to load the rest of the Second stage bootloader from flash. These are used to configure the SPI flash during boot. bin file contains a header with CONFIG_ESPTOOLPY_FLASHMODE, CONFIG_ESPTOOLPY_FLASHFREQ, CONFIG_ESPTOOLPY_FLASHSIZE embedded in it.

Use original boot configuration