nRF5340 Custom Board App not booting when enabling CONFIG_BOOTLOADER_MCUBOOT

[responsible_duck]

Hello,

We have a custom board using a nRF5340. 

We followed this course implementation for simple serial recovery over UART (and also tried CDC ACM) but as soon as activate CONFIG_BOOTLOADER_MCUBOOT=y our app doesn't load. We deactivate it and it boots up properly. Unfortunately we don't see any logs either via UART or RTT when this flag is on. 

Maybe we are missing something about nRF5340 system. We are just hoping to update the app image core for now. 

Below is our code.

mcuboot.conf:

CONFIG_SIZE_OPTIMIZATIONS=y
CONFIG_SINGLE_APPLICATION_SLOT=y

# Enable MCUboot Serial Recovery
CONFIG_MCUBOOT_SERIAL=y

CONFIG_UART_CONSOLE=n

# Enable wait for DFU functionality
# CONFIG_BOOT_SERIAL_WAIT_FOR_DFU=y
# CONFIG_BOOT_SERIAL_WAIT_FOR_DFU_TIMEOUT=5000

proj.conf:

CONFIG_SOC_NRF5340_CPUAPP_QKAA=y
CONFIG_BOARD_NRF7002DK_NRF5340_CPUAPP=y

# Enable MPU
CONFIG_ARM_MPU=y

# Enable hardware stack protection
CONFIG_HW_STACK_PROTECTION=y

# Enable TrustZone-M
CONFIG_ARM_TRUSTZONE_M=y

# enable GPIO
CONFIG_GPIO=y

# Enable uart driver
CONFIG_SERIAL=y

# enable console
CONFIG_CONSOLE=y
CONFIG_UART_CONSOLE=n
CONFIG_RTT_CONSOLE=y
CONFIG_USE_SEGGER_RTT=y
CONFIG_STDOUT_CONSOLE=y
CONFIG_LOG_MODE_IMMEDIATE=n
CONFIG_BOOT_BANNER=y
# CONFIG_USB_CDC_ACM_LOG_LEVEL_DBG=y

# Kernel settings
CONFIG_ENTROPY_GENERATOR=y
CONFIG_TEST_RANDOM_GENERATOR=y
CONFIG_CRC=y
CONFIG_BASE64=y
CONFIG_NEWLIB_LIBC=y
CONFIG_NEWLIB_LIBC_NANO=n
CONFIG_THREAD_NAME=y
CONFIG_INIT_STACKS=y

# Most of Zephyr allocations use k_alloc, sized with CONFIG_HEAP_MEM_POOL_SIZE.
# But there are also calls to libc malloc() etc. which allocate from the libc heap, which is
# unused memory (end of .bss to end of SRAM) by default. hostap uses libc heap heavily, and
# does not handle failures well (can get stuck in infinite loops).
# So override libc malloc with the Zephyr internal implementation, of a preallocated size, and
# monitor it at runtime to ensure it does not overflow.
# There are still a few allocations remaining on "true" libc stack, about 2.5kB from signal() etc.
# which need to be accommodated by leaving some free RAM in the build.
CONFIG_COMMON_LIBC_MALLOC=y
CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=32768
CONFIG_SYS_HEAP_RUNTIME_STATS=y

# Threads
CONFIG_MAIN_STACK_SIZE=4096
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048
CONFIG_NET_TX_STACK_SIZE=4096
CONFIG_NET_RX_STACK_SIZE=4096
# See Pendant.h for how these priorities fit in.
CONFIG_NRF700X_BH_WQ_PRIORITY=7
CONFIG_WPA_SUPP_WQ_PRIORITY=9
CONFIG_MAIN_THREAD_PRIORITY=13

# Debugging
CONFIG_DEBUG=y
# @todo: This could be enabled if debug is off, should help throughput but at a flash cost.
# CONFIG_SPEED_OPTIMIZATIONS=y
# @todo: Enabling asserts for bringup. This should probably only get enabled for app files, or off.
CONFIG_ASSERT=y
CONFIG_STACK_SENTINEL=y
CONFIG_DEBUG_COREDUMP=n
CONFIG_DEBUG_COREDUMP_BACKEND_LOGGING=n
CONFIG_DEBUG_COREDUMP_MEMORY_DUMP_MIN=y
CONFIG_THREAD_MONITOR=y

# Logging
CONFIG_LOG=y
CONFIG_LOG_BUFFER_SIZE=2048
CONFIG_POSIX_CLOCK=y
# shell_uart (through USB) log defaults to 512 byte buffer and silently drops logs beyond that.
# Add a larger buffer size and timeout so we minimize dropped messages.
CONFIG_SHELL_BACKEND_SERIAL_LOG_MESSAGE_QUEUE_SIZE=4096
CONFIG_SHELL_BACKEND_SERIAL_LOG_MESSAGE_QUEUE_TIMEOUT=500
# Immediate logging and RTT, useful for interactive debugging.
# CONFIG_LOG_MODE_IMMEDIATE=y
# CONFIG_LOG_BACKEND_RTT=y
# CONFIG_LOG_BACKEND_RTT_MODE_DROP=y
# CONFIG_USE_SEGGER_RTT=y

# Peripherals
CONFIG_GPIO=y
CONFIG_SPI=y
CONFIG_AUDIO=n
CONFIG_AUDIO_DMIC=n
# Do NOT enable NRFX_PDM here, because we want to use the locally modified file.
CONFIG_NRFX_PDM=n
CONFIG_NRFX_I2S0=y
CONFIG_PWM=y
CONFIG_I2C=y
CONFIG_SENSOR=y
CONFIG_BQ274XX=y

# SHELL AND USB
CONFIG_SHELL=y
CONFIG_SHELL_STACK_SIZE=4096
CONFIG_SHELL_CMDS_RESIZE=n
CONFIG_USB_DEVICE_STACK=y
CONFIG_USB_CDC_ACM=y
CONFIG_USB_DEVICE_PID=0x0110
CONFIG_USB_DEVICE_INITIALIZE_AT_BOOT=y
CONFIG_UART_INTERRUPT_DRIVEN=y
#CONFIG_USB_DEVICE_STACK=y
CONFIG_USB_DEVICE_PRODUCT="Limitless Pendant V1"
#CONFIG_USB_DEVICE_VID=4440

# NVM using internal flash.
CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_FLASH_MAP=y
# Disable flash shell, as it has the same name as pendant flash commmands
CONFIG_FLASH_SHELL=n
CONFIG_NVS=y
CONFIG_SETTINGS=y
CONFIG_SETTINGS_NVS=y
CONFIG_SETTINGS_SHELL=y
CONFIG_WIFI_CREDENTIALS=y
CONFIG_WIFI_CREDENTIALS_BACKEND_SETTINGS=y
CONFIG_WIFI_CREDENTIALS_MAX_ENTRIES=16
CONFIG_WIFI_CREDENTIALS_SHELL=y

# WiFi and Networking
CONFIG_WIFI=y
CONFIG_WIFI_NRF700X=y
CONFIG_WPA_SUPP=y
CONFIG_NRF700X_AP_MODE=n
CONFIG_NRF700X_P2P_MODE=n
CONFIG_NRF700X_UTIL=n
# @todo: Check whether this has a significant impact on performance/power. Default is enabled.
# CONFIG_NRF700X_QSPI_LOW_POWER=n
CONFIG_NETWORKING=y
CONFIG_NET_L2_ETHERNET=y
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_POSIX_NAMES=y
CONFIG_NET_CONTEXT_SNDTIMEO=y
CONFIG_NET_CONTEXT_NET_PKT_POOL=y
CONFIG_NET_LOG=y
CONFIG_NET_IPV4=y
# IPv6 hasn't been tested, and likely various things will need to be updated to support it.
# Disable until we need it.
CONFIG_NET_IPV6=n
CONFIG_NET_UDP=y
CONFIG_NET_TCP=y
CONFIG_NET_DHCPV4=y
CONFIG_NET_CONTEXT_SYNC_RECV=y
CONFIG_NET_MAX_CONN=4
CONFIG_NET_TC_TX_COUNT=1
CONFIG_NET_IF_UNICAST_IPV4_ADDR_COUNT=1
CONFIG_NET_MAX_CONTEXTS=6
CONFIG_NET_SOCKETS_POLL_MAX=6
CONFIG_POSIX_MAX_FDS=16
CONFIG_NET_MGMT_EVENT_QUEUE_TIMEOUT=5000
CONFIG_NET_CONFIG_SETTINGS=n
CONFIG_NET_CONFIG_AUTO_INIT=n
CONFIG_WIFI_MGMT_EXT_CONNECTION_TIMEOUT=30
CONFIG_HTTP_CLIENT=y
CONFIG_WEBSOCKET_CLIENT=y

# The following sections tune the networking stack for memory or performance, and only one section
# should be enabled.
# The settings come from the NCS v2.6.0 wifi/throughput sample, with the expected performance
# listed in the following page:
# https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/wifi/throughput/README.html

# Memory optimized
#CONFIG_HEAP_MEM_POOL_SIZE=80000
#CONFIG_NET_PKT_TX_COUNT=6
#CONFIG_NET_PKT_RX_COUNT=6
#CONFIG_NET_BUF_TX_COUNT=12
#CONFIG_NET_BUF_RX_COUNT=6
#CONFIG_NRF700X_RX_NUM_BUFS=6
#CONFIG_NET_BUF_DATA_SIZE=500
#CONFIG_NRF700X_MAX_TX_AGGREGATION=1
#CONFIG_NRF700X_MAX_TX_TOKENS=5

# IoT devices
CONFIG_HEAP_MEM_POOL_SIZE=100000
CONFIG_NET_PKT_TX_COUNT=6
CONFIG_NET_PKT_RX_COUNT=6
CONFIG_NET_BUF_TX_COUNT=12
CONFIG_NET_BUF_RX_COUNT=6
CONFIG_NRF700X_RX_NUM_BUFS=6
CONFIG_NET_BUF_DATA_SIZE=800
CONFIG_NRF700X_MAX_TX_AGGREGATION=1
CONFIG_NRF700X_MAX_TX_TOKENS=5

# High performance
# This is unlikely to compile without RAM overflow.
#CONFIG_HEAP_MEM_POOL_SIZE=230000
#CONFIG_NET_PKT_TX_COUNT=30
#CONFIG_NET_PKT_RX_COUNT=30
#CONFIG_NET_BUF_TX_COUNT=60
#CONFIG_NET_BUF_RX_COUNT=30
#CONFIG_NRF700X_RX_NUM_BUFS=48
#CONFIG_NET_BUF_DATA_SIZE=1100
#CONFIG_NRF700X_MAX_TX_AGGREGATION=9
#CONFIG_NRF700X_MAX_TX_TOKENS=12

# Enable MCUBoot
CONFIG_BOOTLOADER_MCUBOOT=y

# Size optimization
CONFIG_SIZE_OPTIMIZATIONS=y

pm_static.yml to set mcuboot partition size to fit:

mcuboot:
  address: 0x0
  end_address: 0x10000
  placement:
    before:
    - mcuboot_primary
  region: flash_primary
  size: 0x10000

Our .dts partition layout, although I think Partition Manager overrides this:

&flash0 {

	partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		boot_partition: partition@0 {
			label = "mcuboot";
			reg = <0x00000000 0x00010000>;
		};
		slot0_partition: partition@10000 {
			label = "image-0";
		};
		// slot0_ns_partition: partition@50000 {
		// 	label = "image-0-nonsecure";
		// };
		// slot1_partition: partition@80000 {
		// 	label = "image-1";
		// };
		// slot1_ns_partition: partition@c0000 {
		// 	label = "image-1-nonsecure";
		// };
		// scratch_partition: partition@f0000 {
		// 	label = "image-scratch";
		// 	reg = <0x000f0000 0xa000>;
		// };
		storage_partition: partition@fc000 {
			label = "settings";
			reg = <0x000fc000 0x0004000>;
		};
	};
};

Our partitions.yml output:

EMPTY_0:
  address: 0xfe000
  end_address: 0x100000
  placement:
    after:
    - settings_storage
  region: flash_primary
  size: 0x2000
app:
  address: 0x10200
  end_address: 0xfc000
  region: flash_primary
  size: 0xebe00
mcuboot:
  address: 0x0
  end_address: 0x10000
  placement:
    before:
    - mcuboot_primary
  region: flash_primary
  size: 0x10000
mcuboot_pad:
  address: 0x10000
  end_address: 0x10200
  placement:
    align:
      start: 0x4000
    before:
    - mcuboot_primary_app
  region: flash_primary
  size: 0x200
mcuboot_primary:
  address: 0x10000
  end_address: 0xfc000
  orig_span: &id001
  - mcuboot_pad
  - app
  region: flash_primary
  size: 0xec000
  span: *id001
mcuboot_primary_app:
  address: 0x10200
  end_address: 0xfc000
  orig_span: &id002
  - app
  region: flash_primary
  size: 0xebe00
  span: *id002
otp:
  address: 0xff8100
  end_address: 0xff83fc
  region: otp
  size: 0x2fc
rpmsg_nrf53_sram:
  address: 0x20070000
  end_address: 0x20080000
  placement:
    before:
    - end
  region: sram_primary
  size: 0x10000
settings_storage:
  address: 0xfc000
  end_address: 0xfe000
  placement:
    align:
      start: 0x4000
    before:
    - end
  region: flash_primary
  size: 0x2000
sram_primary:
  address: 0x20000000
  end_address: 0x20070000
  region: sram_primary
  size: 0x70000

[trampas]

Just out of curiosity is the 32Khz crystal connected?  We had issues of not booting where code was expecting a crystal and we did not have one and needed to enable the RC option.  

[responsible_duck]

Hmm based on your insight I found this discussion and enabled these flags in `child_image/mcuboot.conf`:

CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y
CONFIG_CLOCK_CONTROL_NRF_K32SRC_500PPM=y

It still didn't turn on after flashing successfully but then I came across this discussion which recommends power cycling. And it seems our device boots! And we can now use mcumgr to update the firmware in serial recovery mode. 

Appreciate it. 

[trampas]

A trick a friend told me was to enable the RC settings in your custom board files, then everything that is compiled with that board will configure and use the RC instead of crystal.