mirror of
https://github.com/espressif/esp-idf.git
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ea476f1731
bootloader: Fix warnings caused by security features (v4.2) See merge request espressif/esp-idf!12286
787 lines
37 KiB
Plaintext
787 lines
37 KiB
Plaintext
menu "Bootloader config"
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choice BOOTLOADER_COMPILER_OPTIMIZATION
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prompt "Bootloader optimization Level"
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default BOOTLOADER_COMPILER_OPTIMIZATION_SIZE
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help
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This option sets compiler optimization level (gcc -O argument)
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for the bootloader.
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- The default "Size" setting will add the -0s flag to CFLAGS.
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- The "Debug" setting will add the -Og flag to CFLAGS.
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- The "Performance" setting will add the -O2 flag to CFLAGS.
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- The "None" setting will add the -O0 flag to CFLAGS.
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Note that custom optimization levels may be unsupported.
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config BOOTLOADER_COMPILER_OPTIMIZATION_SIZE
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bool "Size (-Os)"
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config BOOTLOADER_COMPILER_OPTIMIZATION_DEBUG
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bool "Debug (-Og)"
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config BOOTLOADER_COMPILER_OPTIMIZATION_PERF
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bool "Optimize for performance (-O2)"
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config BOOTLOADER_COMPILER_OPTIMIZATION_NONE
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bool "Debug without optimization (-O0)"
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endchoice
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choice BOOTLOADER_LOG_LEVEL
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bool "Bootloader log verbosity"
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default BOOTLOADER_LOG_LEVEL_INFO
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help
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Specify how much output to see in bootloader logs.
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config BOOTLOADER_LOG_LEVEL_NONE
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bool "No output"
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config BOOTLOADER_LOG_LEVEL_ERROR
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bool "Error"
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config BOOTLOADER_LOG_LEVEL_WARN
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bool "Warning"
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config BOOTLOADER_LOG_LEVEL_INFO
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bool "Info"
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config BOOTLOADER_LOG_LEVEL_DEBUG
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bool "Debug"
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config BOOTLOADER_LOG_LEVEL_VERBOSE
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bool "Verbose"
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endchoice
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config BOOTLOADER_LOG_LEVEL
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int
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default 0 if BOOTLOADER_LOG_LEVEL_NONE
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default 1 if BOOTLOADER_LOG_LEVEL_ERROR
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default 2 if BOOTLOADER_LOG_LEVEL_WARN
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default 3 if BOOTLOADER_LOG_LEVEL_INFO
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default 4 if BOOTLOADER_LOG_LEVEL_DEBUG
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default 5 if BOOTLOADER_LOG_LEVEL_VERBOSE
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config BOOTLOADER_SPI_CUSTOM_WP_PIN
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bool "Use custom SPI Flash WP Pin when flash pins set in eFuse (read help)"
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depends on IDF_TARGET_ESP32 && (ESPTOOLPY_FLASHMODE_QIO || ESPTOOLPY_FLASHMODE_QOUT)
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default y if BOOTLOADER_SPI_WP_PIN != 7 # backwards compatibility, can remove in IDF 5
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default n
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help
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This setting is only used if the SPI flash pins have been overridden by setting the eFuses
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SPI_PAD_CONFIG_xxx, and the SPI flash mode is QIO or QOUT.
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When this is the case, the eFuse config only defines 3 of the 4 Quad I/O data pins. The WP pin (aka
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ESP32 pin "SD_DATA_3" or SPI flash pin "IO2") is not specified in eFuse. The same pin is also used
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for external SPIRAM if it is enabled.
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If this config item is set to N (default), the correct WP pin will be automatically used for any
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Espressif chip or module with integrated flash. If a custom setting is needed, set this config item to
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Y and specify the GPIO number connected to the WP.
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config BOOTLOADER_SPI_WP_PIN
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int "Custom SPI Flash WP Pin"
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range 0 33
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default 7
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depends on IDF_TARGET_ESP32 && (ESPTOOLPY_FLASHMODE_QIO || ESPTOOLPY_FLASHMODE_QOUT)
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#depends on BOOTLOADER_SPI_CUSTOM_WP_PIN # backwards compatibility, can uncomment in IDF 5
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help
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The option "Use custom SPI Flash WP Pin" must be set or this value is ignored
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If burning a customized set of SPI flash pins in eFuse and using QIO or QOUT mode for flash, set this
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value to the GPIO number of the SPI flash WP pin.
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choice BOOTLOADER_VDDSDIO_BOOST
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bool "VDDSDIO LDO voltage"
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default BOOTLOADER_VDDSDIO_BOOST_1_9V
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help
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If this option is enabled, and VDDSDIO LDO is set to 1.8V (using eFuse
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or MTDI bootstrapping pin), bootloader will change LDO settings to
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output 1.9V instead. This helps prevent flash chip from browning out
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during flash programming operations.
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This option has no effect if VDDSDIO is set to 3.3V, or if the internal
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VDDSDIO regulator is disabled via eFuse.
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config BOOTLOADER_VDDSDIO_BOOST_1_8V
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bool "1.8V"
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depends on !ESPTOOLPY_FLASHFREQ_80M
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config BOOTLOADER_VDDSDIO_BOOST_1_9V
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bool "1.9V"
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endchoice
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config BOOTLOADER_FACTORY_RESET
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bool "GPIO triggers factory reset"
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default N
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help
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Allows to reset the device to factory settings:
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- clear one or more data partitions;
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- boot from "factory" partition.
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The factory reset will occur if there is a GPIO input pulled low while device starts up.
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See settings below.
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config BOOTLOADER_NUM_PIN_FACTORY_RESET
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int "Number of the GPIO input for factory reset"
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depends on BOOTLOADER_FACTORY_RESET
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range 0 39
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default 4
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help
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The selected GPIO will be configured as an input with internal pull-up enabled.
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To trigger a factory reset, this GPIO must be pulled low on reset.
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Note that GPIO34-39 do not have an internal pullup and an external one must be provided.
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config BOOTLOADER_OTA_DATA_ERASE
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bool "Clear OTA data on factory reset (select factory partition)"
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depends on BOOTLOADER_FACTORY_RESET
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help
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The device will boot from "factory" partition (or OTA slot 0 if no factory partition is present) after a
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factory reset.
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config BOOTLOADER_DATA_FACTORY_RESET
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string "Comma-separated names of partitions to clear on factory reset"
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depends on BOOTLOADER_FACTORY_RESET
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default "nvs"
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help
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Allows customers to select which data partitions will be erased while factory reset.
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Specify the names of partitions as a comma-delimited with optional spaces for readability. (Like this:
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"nvs, phy_init, ...")
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Make sure that the name specified in the partition table and here are the same.
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Partitions of type "app" cannot be specified here.
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config BOOTLOADER_APP_TEST
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bool "GPIO triggers boot from test app partition"
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default N
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help
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Allows to run the test app from "TEST" partition.
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A boot from "test" partition will occur if there is a GPIO input pulled low while device starts up.
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See settings below.
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config BOOTLOADER_NUM_PIN_APP_TEST
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int "Number of the GPIO input to boot TEST partition"
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depends on BOOTLOADER_APP_TEST
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range 0 39
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default 18
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help
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The selected GPIO will be configured as an input with internal pull-up enabled.
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To trigger a test app, this GPIO must be pulled low on reset.
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After the GPIO input is deactivated and the device reboots, the old application will boot.
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(factory or OTA[x]).
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Note that GPIO34-39 do not have an internal pullup and an external one must be provided.
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config BOOTLOADER_HOLD_TIME_GPIO
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int "Hold time of GPIO for reset/test mode (seconds)"
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depends on BOOTLOADER_FACTORY_RESET || BOOTLOADER_APP_TEST
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default 5
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help
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The GPIO must be held low continuously for this period of time after reset
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before a factory reset or test partition boot (as applicable) is performed.
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config BOOTLOADER_WDT_ENABLE
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bool "Use RTC watchdog in start code"
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default y
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help
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Tracks the execution time of startup code.
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If the execution time is exceeded, the RTC_WDT will restart system.
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It is also useful to prevent a lock up in start code caused by an unstable power source.
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NOTE: Tracks the execution time starts from the bootloader code - re-set timeout, while selecting the
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source for slow_clk - and ends calling app_main.
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Re-set timeout is needed due to WDT uses a SLOW_CLK clock source. After changing a frequency slow_clk a
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time of WDT needs to re-set for new frequency.
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slow_clk depends on ESP32_RTC_CLK_SRC (INTERNAL_RC or EXTERNAL_CRYSTAL).
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config BOOTLOADER_WDT_DISABLE_IN_USER_CODE
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bool "Allows RTC watchdog disable in user code"
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depends on BOOTLOADER_WDT_ENABLE
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default n
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help
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If it is set, the client must itself reset or disable rtc_wdt in their code (app_main()).
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Otherwise rtc_wdt will be disabled before calling app_main function.
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Use function rtc_wdt_feed() for resetting counter of rtc_wdt.
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Use function rtc_wdt_disable() for disabling rtc_wdt.
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config BOOTLOADER_WDT_TIME_MS
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int "Timeout for RTC watchdog (ms)"
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depends on BOOTLOADER_WDT_ENABLE
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default 9000
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range 0 120000
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help
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Verify that this parameter is correct and more then the execution time.
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Pay attention to options such as reset to factory, trigger test partition and encryption on boot
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- these options can increase the execution time.
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Note: RTC_WDT will reset while encryption operations will be performed.
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config BOOTLOADER_APP_ROLLBACK_ENABLE
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bool "Enable app rollback support"
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default n
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help
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After updating the app, the bootloader runs a new app with the "ESP_OTA_IMG_PENDING_VERIFY" state set.
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This state prevents the re-run of this app. After the first boot of the new app in the user code, the
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function should be called to confirm the operability of the app or vice versa about its non-operability.
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If the app is working, then it is marked as valid. Otherwise, it is marked as not valid and rolls back to
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the previous working app. A reboot is performed, and the app is booted before the software update.
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Note: If during the first boot a new app the power goes out or the WDT works, then roll back will happen.
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Rollback is possible only between the apps with the same security versions.
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config BOOTLOADER_APP_ANTI_ROLLBACK
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bool "Enable app anti-rollback support"
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depends on BOOTLOADER_APP_ROLLBACK_ENABLE
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default n
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help
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This option prevents rollback to previous firmware/application image with lower security version.
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config BOOTLOADER_APP_SECURE_VERSION
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int "eFuse secure version of app"
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depends on BOOTLOADER_APP_ANTI_ROLLBACK
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default 0
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help
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The secure version is the sequence number stored in the header of each firmware.
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The security version is set in the bootloader, version is recorded in the eFuse field
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as the number of set ones. The allocated number of bits in the efuse field
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for storing the security version is limited (see BOOTLOADER_APP_SEC_VER_SIZE_EFUSE_FIELD option).
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Bootloader: When bootloader selects an app to boot, an app is selected that has
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a security version greater or equal that recorded in eFuse field.
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The app is booted with a higher (or equal) secure version.
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The security version is worth increasing if in previous versions there is
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a significant vulnerability and their use is not acceptable.
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Your partition table should has a scheme with ota_0 + ota_1 (without factory).
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config BOOTLOADER_APP_SEC_VER_SIZE_EFUSE_FIELD
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int "Size of the efuse secure version field"
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depends on BOOTLOADER_APP_ANTI_ROLLBACK
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range 1 32 if IDF_TARGET_ESP32
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default 32 if IDF_TARGET_ESP32
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range 1 16 if IDF_TARGET_ESP32S2
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default 16 if IDF_TARGET_ESP32S2
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help
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The size of the efuse secure version field.
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Its length is limited to 32 bits for ESP32 and 16 bits for ESP32-S2.
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This determines how many times the security version can be increased.
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config BOOTLOADER_EFUSE_SECURE_VERSION_EMULATE
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bool "Emulate operations with efuse secure version(only test)"
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default n
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depends on BOOTLOADER_APP_ANTI_ROLLBACK
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help
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This option allow emulate read/write operations with efuse secure version.
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It allow to test anti-rollback implemention without permanent write eFuse bits.
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In partition table should be exist this partition `emul_efuse, data, 5, , 0x2000`.
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config BOOTLOADER_SKIP_VALIDATE_IN_DEEP_SLEEP
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bool "Skip image validation when exiting deep sleep"
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depends on (SECURE_BOOT && SECURE_BOOT_INSECURE) || !SECURE_BOOT
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default n
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help
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This option disables the normal validation of an image coming out of
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deep sleep (checksums, SHA256, and signature). This is a trade-off
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between wakeup performance from deep sleep, and image integrity checks.
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Only enable this if you know what you are doing. It should not be used
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in conjunction with using deep_sleep() entry and changing the active OTA
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partition as this would skip the validation upon first load of the new
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OTA partition.
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config BOOTLOADER_RESERVE_RTC_SIZE
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hex
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default 0x10 if BOOTLOADER_SKIP_VALIDATE_IN_DEEP_SLEEP || BOOTLOADER_CUSTOM_RESERVE_RTC
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default 0
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help
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Reserve RTC FAST memory for Skip image validation. This option in bytes.
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This option reserves an area in the RTC FAST memory (access only PRO_CPU).
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Used to save the addresses of the selected application.
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When a wakeup occurs (from Deep sleep), the bootloader retrieves it and
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loads the application without validation.
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config BOOTLOADER_CUSTOM_RESERVE_RTC
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bool "Reserve RTC FAST memory for custom purposes"
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default n
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help
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This option allows the customer to place data in the RTC FAST memory,
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this area remains valid when rebooted, except for power loss.
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This memory is located at a fixed address and is available
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for both the bootloader and the application.
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(The application and bootoloader must be compiled with the same option).
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The RTC FAST memory has access only through PRO_CPU.
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config BOOTLOADER_CUSTOM_RESERVE_RTC_SIZE
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hex "Size in bytes for custom purposes"
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range 0 0x10
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default 0
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depends on BOOTLOADER_CUSTOM_RESERVE_RTC
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help
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This option reserves in RTC FAST memory the area for custom purposes.
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If you want to create your own bootloader and save more information
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in this area of memory, you can increase it. It must be a multiple of 4 bytes.
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This area (rtc_retain_mem_t) is reserved and has access from the bootloader and an application.
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endmenu # Bootloader
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menu "Security features"
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# These three are the actual options to check in code,
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# selected by the displayed options
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config SECURE_SIGNED_ON_BOOT
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bool
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default y
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depends on SECURE_BOOT || SECURE_SIGNED_ON_BOOT_NO_SECURE_BOOT
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config SECURE_SIGNED_ON_UPDATE
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bool
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default y
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depends on SECURE_BOOT || SECURE_SIGNED_ON_UPDATE_NO_SECURE_BOOT
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config SECURE_SIGNED_APPS
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bool
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default y
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select MBEDTLS_ECP_DP_SECP256R1_ENABLED
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select MBEDTLS_ECP_C
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select MBEDTLS_ECDH_C
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select MBEDTLS_ECDSA_C
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depends on SECURE_SIGNED_ON_BOOT || SECURE_SIGNED_ON_UPDATE
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config SECURE_BOOT_SUPPORTS_RSA
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bool
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default y
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depends on ESP32_REV_MIN_3 || IDF_TARGET_ESP32S2
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config SECURE_TARGET_HAS_SECURE_ROM_DL_MODE
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bool
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default y
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depends on IDF_TARGET_ESP32S2
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config SECURE_SIGNED_APPS_NO_SECURE_BOOT
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bool "Require signed app images"
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depends on !SECURE_BOOT
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help
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Require apps to be signed to verify their integrity.
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This option uses the same app signature scheme as hardware secure boot, but unlike hardware secure boot it
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does not prevent the bootloader from being physically updated. This means that the device can be secured
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against remote network access, but not physical access. Compared to using hardware Secure Boot this option
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is much simpler to implement.
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choice SECURE_SIGNED_APPS_SCHEME
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bool "App Signing Scheme"
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depends on SECURE_BOOT || SECURE_SIGNED_APPS_NO_SECURE_BOOT
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default SECURE_SIGNED_APPS_ECDSA_SCHEME if SECURE_BOOT_V1_ENABLED
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default SECURE_SIGNED_APPS_RSA_SCHEME if SECURE_BOOT_V2_ENABLED
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help
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Select the Secure App signing scheme. Depends on the Chip Revision.
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There are two options:
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1. ECDSA based secure boot scheme. (Only choice for Secure Boot V1)
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Supported in ESP32 and ESP32-ECO3.
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2. The RSA based secure boot scheme. (Only choice for Secure Boot V2)
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Supported in ESP32-ECO3. (ESP32 Chip Revision 3 onwards)
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config SECURE_SIGNED_APPS_ECDSA_SCHEME
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bool "ECDSA"
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depends on IDF_TARGET_ESP32 && (SECURE_SIGNED_APPS_NO_SECURE_BOOT || SECURE_BOOT_V1_ENABLED)
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help
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Embeds the ECDSA public key in the bootloader and signs the application with an ECDSA key.
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Refer to the documentation before enabling.
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config SECURE_SIGNED_APPS_RSA_SCHEME
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bool "RSA"
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depends on SECURE_BOOT_SUPPORTS_RSA && SECURE_BOOT_V2_ENABLED
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help
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Appends the RSA-3072 based Signature block to the application.
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Refer to <Secure Boot Version 2 documentation link> before enabling.
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endchoice
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config SECURE_SIGNED_ON_BOOT_NO_SECURE_BOOT
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bool "Bootloader verifies app signatures"
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default n
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depends on SECURE_SIGNED_APPS_NO_SECURE_BOOT
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help
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If this option is set, the bootloader will be compiled with code to verify that an app is signed before
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booting it.
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If hardware secure boot is enabled, this option is always enabled and cannot be disabled.
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If hardware secure boot is not enabled, this option doesn't add significant security by itself so most
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users will want to leave it disabled.
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config SECURE_SIGNED_ON_UPDATE_NO_SECURE_BOOT
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bool "Verify app signature on update"
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default y
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depends on SECURE_SIGNED_APPS_NO_SECURE_BOOT
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help
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If this option is set, any OTA updated apps will have the signature verified before being considered valid.
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When enabled, the signature is automatically checked whenever the esp_ota_ops.h APIs are used for OTA
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updates, or esp_image_format.h APIs are used to verify apps.
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If hardware secure boot is enabled, this option is always enabled and cannot be disabled.
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If hardware secure boot is not enabled, this option still adds significant security against network-based
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attackers by preventing spoofing of OTA updates.
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config SECURE_BOOT
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bool "Enable hardware Secure Boot in bootloader (READ DOCS FIRST)"
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default n
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help
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Build a bootloader which enables Secure Boot on first boot.
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Once enabled, Secure Boot will not boot a modified bootloader. The bootloader will only load a partition
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table or boot an app if the data has a verified digital signature. There are implications for reflashing
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updated apps once secure boot is enabled.
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When enabling secure boot, JTAG and ROM BASIC Interpreter are permanently disabled by default.
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choice SECURE_BOOT_VERSION
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bool "Select secure boot version"
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default SECURE_BOOT_V2_ENABLED if ESP32_REV_MIN_3
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depends on SECURE_BOOT
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help
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Select the Secure Boot Version. Depends on the Chip Revision.
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Secure Boot V2 is the new RSA based secure boot scheme.
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Supported in ESP32-ECO3. (ESP32 Chip Revision 3 onwards)
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Secure Boot V1 is the AES based secure boot scheme.
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Supported in ESP32 and ESP32-ECO3.
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config SECURE_BOOT_V1_ENABLED
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bool "Enable Secure Boot version 1"
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depends on IDF_TARGET_ESP32
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help
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Build a bootloader which enables secure boot version 1 on first boot.
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Refer to the Secure Boot section of the ESP-IDF Programmer's Guide for this version before enabling.
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config SECURE_BOOT_V2_ENABLED
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bool "Enable Secure Boot version 2"
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depends on SECURE_BOOT_SUPPORTS_RSA
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select SECURE_ENABLE_SECURE_ROM_DL_MODE if !IDF_TARGET_ESP32 && !SECURE_INSECURE_ALLOW_DL_MODE
|
|
select SECURE_DISABLE_ROM_DL_MODE if ESP32_REV_MIN_3 && !SECURE_INSECURE_ALLOW_DL_MODE
|
|
help
|
|
Build a bootloader which enables Secure Boot version 2 on first boot.
|
|
Refer to Secure Boot V2 section of the ESP-IDF Programmer's Guide for this version before enabling.
|
|
|
|
endchoice
|
|
|
|
choice SECURE_BOOTLOADER_MODE
|
|
bool "Secure bootloader mode"
|
|
depends on SECURE_BOOT_V1_ENABLED
|
|
default SECURE_BOOTLOADER_ONE_TIME_FLASH
|
|
|
|
config SECURE_BOOTLOADER_ONE_TIME_FLASH
|
|
bool "One-time flash"
|
|
help
|
|
On first boot, the bootloader will generate a key which is not readable externally or by software. A
|
|
digest is generated from the bootloader image itself. This digest will be verified on each subsequent
|
|
boot.
|
|
|
|
Enabling this option means that the bootloader cannot be changed after the first time it is booted.
|
|
|
|
config SECURE_BOOTLOADER_REFLASHABLE
|
|
bool "Reflashable"
|
|
help
|
|
Generate a reusable secure bootloader key, derived (via SHA-256) from the secure boot signing key.
|
|
|
|
This allows the secure bootloader to be re-flashed by anyone with access to the secure boot signing
|
|
key.
|
|
|
|
This option is less secure than one-time flash, because a leak of the digest key from one device
|
|
allows reflashing of any device that uses it.
|
|
|
|
endchoice
|
|
|
|
config SECURE_BOOT_BUILD_SIGNED_BINARIES
|
|
bool "Sign binaries during build"
|
|
depends on SECURE_SIGNED_APPS
|
|
default y
|
|
help
|
|
Once secure boot or signed app requirement is enabled, app images are required to be signed.
|
|
|
|
If enabled (default), these binary files are signed as part of the build process. The file named in
|
|
"Secure boot private signing key" will be used to sign the image.
|
|
|
|
If disabled, unsigned app/partition data will be built. They must be signed manually using espsecure.py.
|
|
Version 1 to enable ECDSA Based Secure Boot and Version 2 to enable RSA based Secure Boot.
|
|
(for example, on a remote signing server.)
|
|
|
|
config SECURE_BOOT_SIGNING_KEY
|
|
string "Secure boot private signing key"
|
|
depends on SECURE_BOOT_BUILD_SIGNED_BINARIES
|
|
default "secure_boot_signing_key.pem"
|
|
help
|
|
Path to the key file used to sign app images.
|
|
|
|
Key file is an ECDSA private key (NIST256p curve) in PEM format for Secure Boot V1.
|
|
Key file is an RSA private key in PEM format for Secure Boot V2.
|
|
|
|
Path is evaluated relative to the project directory.
|
|
|
|
You can generate a new signing key by running the following command:
|
|
espsecure.py generate_signing_key secure_boot_signing_key.pem
|
|
|
|
See the Secure Boot section of the ESP-IDF Programmer's Guide for this version for details.
|
|
|
|
config SECURE_BOOT_VERIFICATION_KEY
|
|
string "Secure boot public signature verification key"
|
|
depends on SECURE_SIGNED_APPS && !SECURE_BOOT_BUILD_SIGNED_BINARIES && !SECURE_SIGNED_APPS_RSA_SCHEME
|
|
default "signature_verification_key.bin"
|
|
help
|
|
Path to a public key file used to verify signed images.
|
|
Secure Boot V1: This ECDSA public key is compiled into the bootloader and/or
|
|
app, to verify app images.
|
|
Secure Boot V2: This RSA public key is compiled into the signature block at
|
|
the end of the bootloader/app.
|
|
|
|
Key file is in raw binary format, and can be extracted from a
|
|
PEM formatted private key using the espsecure.py
|
|
extract_public_key command.
|
|
|
|
Refer to the Secure Boot section of the ESP-IDF Programmer's Guide for this version before enabling.
|
|
|
|
choice SECURE_BOOTLOADER_KEY_ENCODING
|
|
bool "Hardware Key Encoding"
|
|
depends on SECURE_BOOTLOADER_REFLASHABLE
|
|
default SECURE_BOOTLOADER_KEY_ENCODING_256BIT
|
|
help
|
|
|
|
In reflashable secure bootloader mode, a hardware key is derived from the signing key (with SHA-256) and
|
|
can be written to eFuse with espefuse.py.
|
|
|
|
Normally this is a 256-bit key, but if 3/4 Coding Scheme is used on the device then the eFuse key is
|
|
truncated to 192 bits.
|
|
|
|
This configuration item doesn't change any firmware code, it only changes the size of key binary which is
|
|
generated at build time.
|
|
|
|
config SECURE_BOOTLOADER_KEY_ENCODING_256BIT
|
|
bool "No encoding (256 bit key)"
|
|
|
|
config SECURE_BOOTLOADER_KEY_ENCODING_192BIT
|
|
bool "3/4 encoding (192 bit key)"
|
|
|
|
endchoice
|
|
|
|
config SECURE_BOOT_INSECURE
|
|
bool "Allow potentially insecure options"
|
|
depends on SECURE_BOOT
|
|
default N
|
|
help
|
|
You can disable some of the default protections offered by secure boot, in order to enable testing or a
|
|
custom combination of security features.
|
|
|
|
Only enable these options if you are very sure.
|
|
|
|
Refer to the Secure Boot section of the ESP-IDF Programmer's Guide for this version before enabling.
|
|
|
|
config SECURE_FLASH_ENC_ENABLED
|
|
bool "Enable flash encryption on boot (READ DOCS FIRST)"
|
|
default N
|
|
select SPI_FLASH_ENABLE_ENCRYPTED_READ_WRITE
|
|
help
|
|
If this option is set, flash contents will be encrypted by the bootloader on first boot.
|
|
|
|
Note: After first boot, the system will be permanently encrypted. Re-flashing an encrypted
|
|
system is complicated and not always possible.
|
|
|
|
Read https://docs.espressif.com/projects/esp-idf/en/latest/security/flash-encryption.html
|
|
before enabling.
|
|
|
|
choice SECURE_FLASH_ENCRYPTION_KEYSIZE
|
|
bool "Size of generated AES-XTS key"
|
|
default SECURE_FLASH_ENCRYPTION_AES128
|
|
depends on IDF_TARGET_ESP32S2 && SECURE_FLASH_ENC_ENABLED
|
|
help
|
|
Size of generated AES-XTS key.
|
|
|
|
AES-128 uses a 256-bit key (32 bytes) which occupies one Efuse key block.
|
|
AES-256 uses a 512-bit key (64 bytes) which occupies two Efuse key blocks.
|
|
|
|
This setting is ignored if either type of key is already burned to Efuse before the first boot.
|
|
In this case, the pre-burned key is used and no new key is generated.
|
|
|
|
config SECURE_FLASH_ENCRYPTION_AES128
|
|
bool "AES-128 (256-bit key)"
|
|
|
|
config SECURE_FLASH_ENCRYPTION_AES256
|
|
bool "AES-256 (512-bit key)"
|
|
endchoice
|
|
|
|
choice SECURE_FLASH_ENCRYPTION_MODE
|
|
bool "Enable usage mode"
|
|
depends on SECURE_FLASH_ENC_ENABLED
|
|
default SECURE_FLASH_ENCRYPTION_MODE_DEVELOPMENT
|
|
help
|
|
By default Development mode is enabled which allows UART bootloader to perform flash encryption operations
|
|
|
|
Select Release mode only for production or manufacturing. Once enabled you can not reflash using UART
|
|
bootloader
|
|
|
|
Refer to the Secure Boot section of the ESP-IDF Programmer's Guide for this version and
|
|
https://docs.espressif.com/projects/esp-idf/en/latest/security/flash-encryption.html for details.
|
|
|
|
config SECURE_FLASH_ENCRYPTION_MODE_DEVELOPMENT
|
|
bool "Development(NOT SECURE)"
|
|
select SECURE_FLASH_UART_BOOTLOADER_ALLOW_ENC
|
|
|
|
config SECURE_FLASH_ENCRYPTION_MODE_RELEASE
|
|
bool "Release"
|
|
select SECURE_ENABLE_SECURE_ROM_DL_MODE if SECURE_TARGET_HAS_SECURE_ROM_DL_MODE
|
|
|
|
endchoice
|
|
|
|
menu "Potentially insecure options"
|
|
visible if SECURE_FLASH_ENCRYPTION_MODE_DEVELOPMENT || SECURE_BOOT_INSECURE
|
|
|
|
# NOTE: Options in this menu NEED to have SECURE_BOOT_INSECURE
|
|
# and/or SECURE_FLASH_ENCRYPTION_MODE_DEVELOPMENT in "depends on", as the menu
|
|
# itself doesn't enable/disable its children (if it's not set,
|
|
# it's possible for the insecure menu to be disabled but the insecure option
|
|
# to remain on which is very bad.)
|
|
|
|
config SECURE_BOOT_ALLOW_ROM_BASIC
|
|
bool "Leave ROM BASIC Interpreter available on reset"
|
|
depends on (SECURE_BOOT_INSECURE || SECURE_FLASH_ENCRYPTION_MODE_DEVELOPMENT) && IDF_TARGET_ESP32
|
|
default N
|
|
help
|
|
By default, the BASIC ROM Console starts on reset if no valid bootloader is
|
|
read from the flash.
|
|
|
|
When either flash encryption or secure boot are enabled, the default is to
|
|
disable this BASIC fallback mode permanently via eFuse.
|
|
|
|
If this option is set, this eFuse is not burned and the BASIC ROM Console may
|
|
remain accessible. Only set this option in testing environments.
|
|
|
|
config SECURE_BOOT_ALLOW_JTAG
|
|
bool "Allow JTAG Debugging"
|
|
depends on SECURE_BOOT_INSECURE || SECURE_FLASH_ENCRYPTION_MODE_DEVELOPMENT
|
|
default N
|
|
help
|
|
If not set (default), the bootloader will permanently disable JTAG (across entire chip) on first boot
|
|
when either secure boot or flash encryption is enabled.
|
|
|
|
Setting this option leaves JTAG on for debugging, which negates all protections of flash encryption
|
|
and some of the protections of secure boot.
|
|
|
|
Only set this option in testing environments.
|
|
|
|
config SECURE_BOOT_ALLOW_SHORT_APP_PARTITION
|
|
bool "Allow app partition length not 64KB aligned"
|
|
depends on SECURE_BOOT_INSECURE
|
|
help
|
|
If not set (default), app partition size must be a multiple of 64KB. App images are padded to 64KB
|
|
length, and the bootloader checks any trailing bytes after the signature (before the next 64KB
|
|
boundary) have not been written. This is because flash cache maps entire 64KB pages into the address
|
|
space. This prevents an attacker from appending unverified data after the app image in the flash,
|
|
causing it to be mapped into the address space.
|
|
|
|
Setting this option allows the app partition length to be unaligned, and disables padding of the app
|
|
image to this length. It is generally not recommended to set this option, unless you have a legacy
|
|
partitioning scheme which doesn't support 64KB aligned partition lengths.
|
|
|
|
config SECURE_BOOT_V2_ALLOW_EFUSE_RD_DIS
|
|
bool "Allow additional read protecting of efuses"
|
|
depends on SECURE_BOOT_INSECURE && SECURE_BOOT_V2_ENABLED
|
|
help
|
|
If not set (default, recommended), on first boot the bootloader will burn the WR_DIS_RD_DIS
|
|
efuse when Secure Boot is enabled. This prevents any more efuses from being read protected.
|
|
|
|
If this option is set, it will remain possible to write the EFUSE_RD_DIS efuse field after Secure
|
|
Boot is enabled. This may allow an attacker to read-protect the BLK2 efuse holding the public
|
|
key digest, causing an immediate denial of service and possibly allowing an additional fault
|
|
injection attack to bypass the signature protection.
|
|
|
|
config SECURE_INSECURE_ALLOW_DL_MODE
|
|
bool "Don't automatically restrict UART download mode"
|
|
depends on SECURE_BOOT_INSECURE && SECURE_BOOT_V2_ENABLED
|
|
default N
|
|
help
|
|
By default, enabling either flash encryption in release mode or secure boot will automatically
|
|
disable UART download mode on ESP32 ECO3, or enable secure download mode on newer chips.
|
|
This is recommended to reduce the attack surface of the chip.
|
|
|
|
To allow the full UART download mode to stay enabled, enable this option and ensure
|
|
the options SECURE_DISABLE_ROM_DL_MODE and SECURE_ENABLE_SECURE_ROM_DL_MODE are disabled as applicable.
|
|
This is not recommended.
|
|
|
|
config SECURE_FLASH_UART_BOOTLOADER_ALLOW_ENC
|
|
bool "Leave UART bootloader encryption enabled"
|
|
depends on SECURE_FLASH_ENCRYPTION_MODE_DEVELOPMENT
|
|
default N
|
|
help
|
|
If not set (default), the bootloader will permanently disable UART bootloader encryption access on
|
|
first boot. If set, the UART bootloader will still be able to access hardware encryption.
|
|
|
|
It is recommended to only set this option in testing environments.
|
|
|
|
config SECURE_FLASH_UART_BOOTLOADER_ALLOW_DEC
|
|
bool "Leave UART bootloader decryption enabled"
|
|
depends on SECURE_FLASH_ENCRYPTION_MODE_DEVELOPMENT && IDF_TARGET_ESP32
|
|
default N
|
|
help
|
|
If not set (default), the bootloader will permanently disable UART bootloader decryption access on
|
|
first boot. If set, the UART bootloader will still be able to access hardware decryption.
|
|
|
|
Only set this option in testing environments. Setting this option allows complete bypass of flash
|
|
encryption.
|
|
|
|
config SECURE_FLASH_UART_BOOTLOADER_ALLOW_CACHE
|
|
bool "Leave UART bootloader flash cache enabled"
|
|
depends on SECURE_FLASH_ENCRYPTION_MODE_DEVELOPMENT
|
|
default N
|
|
help
|
|
If not set (default), the bootloader will permanently disable UART bootloader flash cache access on
|
|
first boot. If set, the UART bootloader will still be able to access the flash cache.
|
|
|
|
Only set this option in testing environments.
|
|
|
|
config SECURE_FLASH_REQUIRE_ALREADY_ENABLED
|
|
bool "Require flash encryption to be already enabled"
|
|
depends on SECURE_FLASH_ENCRYPTION_MODE_DEVELOPMENT
|
|
default N
|
|
help
|
|
If not set (default), and flash encryption is not yet enabled in eFuses, the 2nd stage bootloader
|
|
will enable flash encryption: generate the flash encryption key and program eFuses.
|
|
If this option is set, and flash encryption is not yet enabled, the bootloader will error out and
|
|
reboot.
|
|
If flash encryption is enabled in eFuses, this option does not change the bootloader behavior.
|
|
|
|
Only use this option in testing environments, to avoid accidentally enabling flash encryption on
|
|
the wrong device. The device needs to have flash encryption already enabled using espefuse.py.
|
|
|
|
endmenu # Potentially Insecure
|
|
|
|
config SECURE_DISABLE_ROM_DL_MODE
|
|
bool "Permanently disable ROM Download Mode"
|
|
depends on !IDF_TARGET_ESP32 || ESP32_REV_MIN_3
|
|
default n
|
|
help
|
|
If set, during startup the app will burn an eFuse bit to permanently disable the UART ROM
|
|
Download Mode. This prevents any future use of esptool.py, espefuse.py and similar tools.
|
|
|
|
Once disabled, if the SoC is booted with strapping pins set for ROM Download Mode
|
|
then an error is printed instead.
|
|
|
|
It is recommended to enable this option in any production application where Flash
|
|
Encryption and/or Secure Boot is enabled and access to Download Mode is not required.
|
|
|
|
It is also possible to permanently disable Download Mode by calling
|
|
esp_efuse_disable_rom_download_mode() at runtime.
|
|
|
|
config SECURE_ENABLE_SECURE_ROM_DL_MODE
|
|
bool "Permanently switch to ROM UART Secure Download mode"
|
|
depends on SECURE_TARGET_HAS_SECURE_ROM_DL_MODE && !SECURE_DISABLE_ROM_DL_MODE
|
|
help
|
|
If set, during startup the app will burn an eFuse bit to permanently switch the UART ROM
|
|
Download Mode into a separate Secure Download mode. This option can only work if
|
|
Download Mode is not already disabled by eFuse.
|
|
|
|
Secure Download mode limits the use of Download Mode functions to simple flash read,
|
|
write and erase operations, plus a command to return a summary of currently enabled
|
|
security features.
|
|
|
|
Secure Download mode is not compatible with the esptool.py flasher stub feature,
|
|
espefuse.py, read/writing memory or registers, encrypted download, or any other
|
|
features that interact with unsupported Download Mode commands.
|
|
|
|
Secure Download mode should be enabled in any application where Flash Encryption
|
|
and/or Secure Boot is enabled. Disabling this option does not immediately cancel
|
|
the benefits of the security features, but it increases the potential "attack
|
|
surface" for an attacker to try and bypass them with a successful physical attack.
|
|
|
|
It is also possible to enable secure download mode at runtime by calling
|
|
esp_efuse_enable_rom_secure_download_mode()
|
|
|
|
|
|
endmenu # Security features
|
|
|