nrf52832: MCUboot in NCS v2.5.1 with direct-xip-revert takes ~800 ms to load an image

RE: nrf52832: MCUboot in NCS v2.5.1 with direct-xip-revert takes ~800 ms to load an image

jrhaws — Tue, 26 Mar 2024 18:45:07 GMT

Yeah, no signature is not an option. And I am already running off the internal clock instead of the crystal.

I'll look into getting hard measurements from the time power is available on the rail to my code running. Right now all I know is that have to provide power for at least 750 ms before I can connect to the device.

I'll get more data and report back.

RE: nrf52832: MCUboot in NCS v2.5.1 with direct-xip-revert takes ~800 ms to load an image

Hieu — Tue, 26 Mar 2024 18:03:36 GMT

Hi jrhaws,

If you want to skip the validation step to save boot time, you can look into CONFIG_BOOT_SIGNATURE_TYPE_NONE. However, this is really not recommended, because it compromises too much security.

Instead, could you please take a look at the discussion in the DevZone case linked below and see if the ideas there can help you?

MCUBOOT Boot time

Hieu

Please be informed that our team is currently having reduced availability due to the Easter holiday. There will be some delays in our response during this time, but we will respond to you at the earliest opportunity. Our apologies for the inconvenience.

RE: nrf52832: MCUboot in NCS v2.5.1 with direct-xip-revert takes ~800 ms to load an image

jrhaws — Thu, 21 Mar 2024 15:58:35 GMT

Hi Hakon,

I finally got around to testing this, and I'm getting warnings in my build and the setting is not getting set. My previous testing was just that the option didn't break the build - it doesn't break it because it doesn't actually get set!

Enabling CONFIG_BOOT_VALIDATE_SLOT0_ONCE does not take effect unless I DISABLE CONFIG_BOOT_VALIDATE_SLOT0 and also ENABLE CONFIG_SINGLE_APPLICATION_SLOT.

This is not what I want to do because when I do, it disables direct-xip bootloader.

Any other thoughts on how we can speed this up?

Thanks!

RE: nrf52832: MCUboot in NCS v2.5.1 with direct-xip-revert takes ~800 ms to load an image

Hakon — Mon, 19 Feb 2024 12:13:51 GMT

[quote user="jrhaws"]Will this configuration option only validate that slot once as well?[/quote]

I believe it should do that, but you should probably test this to be sure.

RE: nrf52832: MCUboot in NCS v2.5.1 with direct-xip-revert takes ~800 ms to load an image

jrhaws — Thu, 08 Feb 2024 23:08:50 GMT

I can confirm that this does allow me to set that option and build. I will do some testing to be certain that it does what I want it to, but I do have a follow up question.

Can you confirm that this will only validate the slots once? I am operating in direct-xip-revert mode in MCUboot, so will boot from slot 1 when that is where the image resides. Will this configuration option only validate that slot once as well?

RE: nrf52832: MCUboot in NCS v2.5.1 with direct-xip-revert takes ~800 ms to load an image

Hakon — Wed, 07 Feb 2024 13:10:13 GMT

Sorry for the confusion, the config should be CONFIG_BOOT_VALIDATE_SLOT0_ONCE. It defines MCUBOOT_VALIDATE_PRIMARY_SLOT_ONCE.

RE: nrf52832: MCUboot in NCS v2.5.1 with direct-xip-revert takes ~800 ms to load an image

jrhaws — Tue, 30 Jan 2024 17:58:23 GMT

Hakon - any more thoughts on this? I'm stuck, having tried everything I can find in the docs.

RE: nrf52832: MCUboot in NCS v2.5.1 with direct-xip-revert takes ~800 ms to load an image

jrhaws — Fri, 26 Jan 2024 22:42:12 GMT

I did give that a try, but it seems that results in build failure. I get similar errors when building with it in proj.conf and mcuboot.conf. I think it belongs in prj.conf, but the docs are not clear. Either way, it will not build with that set.

I also tried setting it in my CMakeLists.txt (which has the same effect as putting it directly in prj.conf) and I get the same errors.

Am I not using/setting it correctly?

C:/git/brickyard_pru/communication/pru_app/child_image/mcuboot.conf:6: warning: attempt to assign the value 'y' to the undefined symbol MCUBOOT_VALIDATE_PRIMARY_SLOT_ONCE

error: Aborting due to Kconfig warnings

RE: nrf52832: MCUboot in NCS v2.5.1 with direct-xip-revert takes ~800 ms to load an image

Hakon — Fri, 26 Jan 2024 14:54:46 GMT

Hello,

I believe you can set MCUBOOT_VALIDATE_PRIMARY_SLOT_ONCE=y, as mentioned here. This can potentially reduce the boot time by a few seconds.

RE: nrf52832: MCUboot in NCS v2.5.1 with direct-xip-revert takes ~800 ms to load an image

jrhaws — Wed, 24 Jan 2024 17:44:25 GMT

I have been able to cut my boot time in half with this mcuboot.conf and prj.conf. The biggest help was to use the internal RC oscillator for MCUboot as well.

Is there anything else I can do to speed things up? Is there a way I can just have the image validated once, instead of everytime (fully understanding the security implications)?

#child_image/mcuboot.conf
CONFIG_BOOT_SIGNATURE_TYPE_ECDSA_P256=y
CONFIG_BOOT_DIRECT_XIP=y
CONFIG_BOOT_DIRECT_XIP_REVERT=y

CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y
CONFIG_MULTITHREADING=y
CONFIG_LOG=n
CONFIG_SERIAL=n
CONFIG_CONSOLE=n
CONFIG_PRINTK=n

# From Nordic to disable Crypto RNG
CONFIG_HW_CC3XX=n
CONFIG_ENTROPY_CC3XX=n
CONFIG_ENTROPY_NRF5_RNG=y
CONFIG_CC3XX_BACKEND=n

# build configuration options
CONFIG_COMPILER_WARNINGS_AS_ERRORS=y

# drivers
CONFIG_FPU=y
CONFIG_WATCHDOG=y
CONFIG_NRFX_TWIS1=y
CONFIG_SPI=y
CONFIG_SPI_SLAVE=y
CONFIG_FLASH=y

# dfu and mcuboot
CONFIG_BOOTLOADER_MCUBOOT=y
CONFIG_STREAM_FLASH_ERASE=y
CONFIG_FLASH_MAP=y
CONFIG_STREAM_FLASH=y
CONFIG_MCUBOOT_IMG_MANAGER=y
CONFIG_IMG_MANAGER=y
CONFIG_MCUBOOT_BOOTLOADER_MODE_DIRECT_XIP_WITH_REVERT=y

# Enable the BLE stack with GATT Server configuration
CONFIG_BT=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_SMP=y
CONFIG_BT_GATT_DYNAMIC_DB=y
CONFIG_BT_DEVICE_NAME="MyDevice"
CONFIG_BT_LIM_ADV_TIMEOUT=60
CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y
CONFIG_BT_RX_STACK_SIZE=1536

# Enable time slicing and multithreading
CONFIG_TIMESLICING=y
CONFIG_TIMESLICE_SIZE=2
CONFIG_MULTITHREADING=y

# Disable Bluetooth features not needed
CONFIG_BT_PHY_UPDATE=n
CONFIG_BT_GATT_CACHING=n
CONFIG_BT_GAP_PERIPHERAL_PREF_PARAMS=n
CONFIG_BT_HCI_VS_EXT=n


# Reduce Bluetooth buffers
CONFIG_BT_BUF_EVT_DISCARDABLE_COUNT=4
CONFIG_BT_BUF_EVT_RX_COUNT=8
CONFIG_BT_L2CAP_TX_BUF_COUNT=16
# CONFIG_BT_CTLR_TX_PWR_MINUS_8=y

# libraries
CONFIG_MINIMAL_LIBC_RAND=y

# debug options
# CONFIG_BT_DEBUG_LOG=y
# CONFIG_ASSERT=y
# CONFIG_DEBUG_THREAD_INFO=y
# CONFIG_DEBUG_OPTIMIZATIONS=y
# CONFIG_SHELL=y
# CONFIG_SIZE_OPTIMIZATIONS=n
# CONFIG_SPEED_OPTIMIZATIONS=n

# release options
CONFIG_BT_DEBUG_NONE=y
CONFIG_ASSERT=n
CONFIG_DEBUG_THREAD_INFO=n
CONFIG_DEBUG_OPTIMIZATIONS=n
CONFIG_SHELL=y
CONFIG_SIZE_OPTIMIZATIONS=y
CONFIG_SPEED_OPTIMIZATIONS=n