Failing to build; region `FLASH' overflowed by 680 bytes

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Amanda Hsieh — Mon, 02 Feb 2026 20:04:22 GMT

It will set the mcuboot partition to 0x7c00 for the mini size. The default size is 0xc000 if you don't use a static partition or CONFIG_PM_PARTITION_SIZE_MCUBOOT.

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Will_20241202 — Mon, 02 Feb 2026 17:47:38 GMT

Ok, but what does that mean? Why wouldn't it always "Build for a minimal image size"? What specifically changes if that option is not yes or is omitted altogether?

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Amanda Hsieh — Mon, 02 Feb 2026 17:44:55 GMT

See https://github.com/nrfconnect/sdk-nrf/blob/v2.7.0/modules/mcuboot/boot/zephyr/Kconfig#L10-L25

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Will_20241202 — Mon, 02 Feb 2026 16:53:17 GMT

Ok, couple new data points:

If I change my build configuration Extra CMake arguments to "-Dmcuboot_CONF_FILE=prj_minimal.conf" it builds without overflowing
Changing to "-Dmcuboot_CONF_FILE=C:/ncs/v2.7.0/bootloader/mcuboot/boot/zephyr/prj_minimal.conf" also builds within permitted size
Editing the prj.conf file in the local mcuboot subdirectoy to mimic the above and using that builds within size
Experimenting with adding back in the original contents of the local prj.conf, the only line that seems to cause issues (meaning it no longer links within the permitted size) is the removal of "CONFIG_BOOT_USE_MIN_PARTITION_SIZE=y"

I cannot find any documentation from Google searching on what exactly this directive does or why I would want it set to either yes or no.

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Amanda Hsieh — Fri, 30 Jan 2026 22:03:42 GMT

Try to build with "-Dmcuboot_CONF_FILE=prj_minimal.conf" to see if it helps.

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Will_20241202 — Fri, 30 Jan 2026 20:20:12 GMT

The only line(s) in the build log that maybe seems suspect is:

=== child image mcuboot - begin ===
loading initial cache file C:/Projects/<REDACTED>/build/mcuboot/child_image_preload.cmake

The rest contains a few warnings (most of which I'm already planning to address, after) but none look like they would impact the mcuboot image. The full (redacted) build log is below.

-----------------------------------------------------------------------------------

* Executing task: nRF Connect: Build [pristine]: <REDACTED>/build (active)

Building <REDACTED>
west build --build-dir c:/Projects/<REDACTED>/build c:/Projects/<REDACTED> --pristine --board my_board --no-sysbuild -- -DNCS_TOOLCHAIN_VERSION="NONE" -DCONF_FILE="prj.conf" -DDEBUG_THREAD_INFO=On -DCONFIG_DEBUG_THREAD_INFO=y -Dmcuboot_EXTRA_CONF_FILE=C:/ncs/v2.7.0/nrf/subsys/partition_manager/partition_manager_enabled.conf -Dmcuboot_CONF_FILE=c:/Projects/<REDACTED>/child_image/mcuboot/prj.conf -DBOARD_ROOT=c:/projects/<REDACTED>

-- west build: generating a build system
Loading Zephyr default modules (Zephyr base).
-- Application: C:/Projects/<REDACTED>
-- CMake version: 3.21.0
-- Found Python3: C:/ncs/toolchains/ce3b5ff664/opt/bin/python.exe (found suitable version "3.9.13", minimum required is "3.8") found components: Interpreter
-- Cache files will be written to: C:/ncs/v2.7.0/zephyr/.cache
-- Zephyr version: 3.6.99 (C:/ncs/v2.7.0/zephyr)
-- Found west (found suitable version "1.2.0", minimum required is "0.14.0")
-- Board: my_board
-- Found host-tools: zephyr 0.16.5 (C:/ncs/toolchains/ce3b5ff664/opt/zephyr-sdk)
-- Found toolchain: zephyr 0.16.5 (C:/ncs/toolchains/ce3b5ff664/opt/zephyr-sdk)
-- Found Dtc: C:/ncs/toolchains/ce3b5ff664/opt/bin/dtc.exe (found suitable version "1.4.7", minimum required is "1.4.6")
-- Found BOARD.dts: C:/Projects/<REDACTED>/boards/arm/MyBoard/my_board.dts
-- Generated zephyr.dts: C:/Projects/<REDACTED>/build/zephyr/zephyr.dts
-- Generated devicetree_generated.h: C:/Projects/<REDACTED>/build/zephyr/include/generated/devicetree_generated.h
-- Including generated dts.cmake file: C:/Projects/<REDACTED>/build/zephyr/dts.cmake

warning: THREAD_MONITOR (defined at kernel/Kconfig:471) was assigned the value 'n' but got the value
'y'. See docs.zephyrproject.org/.../kconfig.html and/or look up
THREAD_MONITOR in the menuconfig/guiconfig interface. The Application Development Primer, Setting
Configuration Values, and Kconfig - Tips and Best Practices sections of the manual might be helpful
too.

warning: Deprecated symbol GPIO_AS_PINRESET is enabled.

warning: Experimental symbol BT_LL_SW_SPLIT is enabled.

Parsing C:/ncs/v2.7.0/zephyr/Kconfig
Loaded configuration 'C:/Projects/<REDACTED>/boards/arm/MyBoard/my_board_defconfig'
Merged configuration 'C:/Projects/<REDACTED>/prj.conf'
Merged configuration 'C:/Projects/<REDACTED>/build/zephyr/misc/generated/extra_kconfig_options.conf'
Configuration saved to 'C:/Projects/<REDACTED>/build/zephyr/.config'
Kconfig header saved to 'C:/Projects/<REDACTED>/build/zephyr/include/generated/autoconf.h'
-- Found GnuLd: c:/ncs/toolchains/ce3b5ff664/opt/zephyr-sdk/arm-zephyr-eabi/arm-zephyr-eabi/bin/ld.bfd.exe (found version "2.38")
-- The C compiler identification is GNU 12.2.0
-- The CXX compiler identification is GNU 12.2.0
-- The ASM compiler identification is GNU
-- Found assembler: C:/ncs/toolchains/ce3b5ff664/opt/zephyr-sdk/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc.exe
CMake Deprecation Warning at C:/ncs/v2.7.0/zephyr/soc/CMakeLists.txt:15 (message):

---------------------------------------------------------------------
--- WARNING: Functionality to describe SoCs in HWMv1 is ---
--- deprecated and should be replaced with HWMv2, including ---
--- boards. HWMv1 SoCs support remains only to ease the migration ---
--- of out-of-tree SoCs and associated boards. It will not be ---
--- possible to build using HWMv1 SoCs at all in future releases. ---
---------------------------------------------------------------------

CMake Warning at C:/ncs/v2.7.0/zephyr/subsys/bluetooth/controller/CMakeLists.txt:4 (message):


CONFIG_BT_CTLR_ADVANCED_FEATURES=y, Advanced Features' default value change
could change Zephyr Bluetooth Controller's functional behavior.

-- Found Python3: C:/ncs/toolchains/ce3b5ff664/opt/bin/python.exe (found version "3.9.13") found components: Interpreter

=== child image mcuboot - begin ===
loading initial cache file C:/Projects/<REDACTED>/build/mcuboot/child_image_preload.cmake
Loading Zephyr default modules (Zephyr base).
-- Application: C:/ncs/v2.7.0/bootloader/mcuboot/boot/zephyr
-- CMake version: 3.21.0
-- Found Python3: C:/ncs/toolchains/ce3b5ff664/opt/bin/python.exe (found suitable version "3.9.13", minimum required is "3.8") found components: Interpreter
-- Cache files will be written to: C:/ncs/v2.7.0/zephyr/.cache
-- Zephyr version: 3.6.99 (C:/ncs/v2.7.0/zephyr)
-- Found west (found suitable version "1.2.0", minimum required is "0.14.0")
-- Board: my_board
-- Found host-tools: zephyr 0.16.5 (C:/ncs/toolchains/ce3b5ff664/opt/zephyr-sdk)
-- Found toolchain: zephyr 0.16.5 (C:/ncs/toolchains/ce3b5ff664/opt/zephyr-sdk)
-- Found Dtc: C:/ncs/toolchains/ce3b5ff664/opt/bin/dtc.exe (found suitable version "1.4.7", minimum required is "1.4.6")
-- Found BOARD.dts: C:/Projects/<REDACTED>/boards/arm/MyBoard/my_board.dts
-- Found devicetree overlay: C:/ncs/v2.7.0/bootloader/mcuboot/boot/zephyr/app.overlay
-- Generated zephyr.dts: C:/Projects/<REDACTED>/build/mcuboot/zephyr/zephyr.dts
-- Generated devicetree_generated.h: C:/Projects/<REDACTED>/build/mcuboot/zephyr/include/generated/devicetree_generated.h
-- Including generated dts.cmake file: C:/Projects/<REDACTED>/build/mcuboot/zephyr/dts.cmake

warning: PRINTK (defined at subsys/debug/Kconfig:204) was assigned the value 'n' but got the value
'y'. See docs.zephyrproject.org/.../kconfig.html and/or look up PRINTK in
the menuconfig/guiconfig interface. The Application Development Primer, Setting Configuration
Values, and Kconfig - Tips and Best Practices sections of the manual might be helpful too.

warning: Deprecated symbol GPIO_AS_PINRESET is enabled.

Parsing C:/ncs/v2.7.0/bootloader/mcuboot/boot/zephyr/Kconfig
Loaded configuration 'C:/Projects/<REDACTED>/boards/arm/MyBoard/my_board_defconfig'
Merged configuration 'c:/Projects/<REDACTED>/child_image/mcuboot/prj.conf'
Merged configuration 'C:/ncs/v2.7.0/nrf/subsys/partition_manager/partition_manager_enabled.conf'
Merged configuration 'C:/Projects/<REDACTED>/build/mcuboot/zephyr/misc/generated/extra_kconfig_options.conf'
Configuration saved to 'C:/Projects/<REDACTED>/build/mcuboot/zephyr/.config'
Kconfig header saved to 'C:/Projects/<REDACTED>/build/mcuboot/zephyr/include/generated/autoconf.h'
-- Found GnuLd: c:/ncs/toolchains/ce3b5ff664/opt/zephyr-sdk/arm-zephyr-eabi/arm-zephyr-eabi/bin/ld.bfd.exe (found version "2.38")
-- The C compiler identification is GNU 12.2.0
-- The CXX compiler identification is GNU 12.2.0
-- The ASM compiler identification is GNU
-- Found assembler: C:/ncs/toolchains/ce3b5ff664/opt/zephyr-sdk/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc.exe
CMake Deprecation Warning at C:/ncs/v2.7.0/zephyr/soc/CMakeLists.txt:15 (message):

---------------------------------------------------------------------
--- WARNING: Functionality to describe SoCs in HWMv1 is ---
--- deprecated and should be replaced with HWMv2, including ---
--- boards. HWMv1 SoCs support remains only to ease the migration ---
--- of out-of-tree SoCs and associated boards. It will not be ---
--- possible to build using HWMv1 SoCs at all in future releases. ---
---------------------------------------------------------------------

CMake Warning at C:/ncs/v2.7.0/nrf/lib/flash_patch/CMakeLists.txt:8 (message):

----------------------------------------------------------
--- WARNING: To maintain the integrity of secure boot, ---
--- enable CONFIG_DISABLE_FLASH_PATCH in production. ---
----------------------------------------------------------

CMake Deprecation Warning at C:/ncs/v2.7.0/nrf/cmake/partition_manager.cmake:32 (message):

---------------------------------------------------------------------
--- WARNING: Child and parent image functionality is deprecated ---
--- and should be replaced with sysbuild. Child and parent image ---
--- support remains only to allow existing customer applications ---
--- to build and allow porting to sysbuild, it is no longer ---
--- receiving updates or new features and it will not be possible ---
--- to build using child/parent image at all in nRF Connect SDK ---
--- version 2.9 onwards. ---
---------------------------------------------------------------------
Call Stack (most recent call first):
C:/ncs/v2.7.0/zephyr/cmake/modules/kernel.cmake:253 (include)
C:/ncs/v2.7.0/zephyr/cmake/modules/zephyr_default.cmake:141 (include)
C:/ncs/v2.7.0/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:66 (include)
C:/ncs/v2.7.0/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:92 (include_boilerplate)
CMakeLists.txt:12 (find_package)

MCUBoot bootloader key file: c:/Projects/<REDACTED>/child_image/mcuboot/my_private_key.pem
-- Configuring done
-- Generating done
-- Build files have been written to: C:/Projects/<REDACTED>/build/mcuboot
=== child image mcuboot - end ===

CMake Deprecation Warning at C:/ncs/v2.7.0/nrf/cmake/partition_manager.cmake:32 (message):

---------------------------------------------------------------------
--- WARNING: Child and parent image functionality is deprecated ---
--- and should be replaced with sysbuild. Child and parent image ---
--- support remains only to allow existing customer applications ---
--- to build and allow porting to sysbuild, it is no longer ---
--- receiving updates or new features and it will not be possible ---
--- to build using child/parent image at all in nRF Connect SDK ---
--- version 2.9 onwards. ---
---------------------------------------------------------------------
Call Stack (most recent call first):
C:/ncs/v2.7.0/zephyr/cmake/modules/kernel.cmake:253 (include)
C:/ncs/v2.7.0/zephyr/cmake/modules/zephyr_default.cmake:141 (include)
C:/ncs/v2.7.0/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:66 (include)
C:/ncs/v2.7.0/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:92 (include_boilerplate)
CMakeLists.txt:2 (find_package)

CMake Warning at C:/ncs/v2.7.0/nrf/cmake/partition_manager.cmake:102 (message):


---------------------------------------------------------------------
--- WARNING: Using a bootloader without pm_static.yml. ---
--- There are cases where a deployed product can consist of ---
--- multiple images, and only a subset of these images can be ---
--- upgraded through a firmware update mechanism. In such cases, ---
--- the upgradable images must have partitions that are static ---
--- and are matching the partition map used by the bootloader ---
--- programmed onto the device. ---
---------------------------------------------------------------------


Call Stack (most recent call first):
C:/ncs/v2.7.0/zephyr/cmake/modules/kernel.cmake:253 (include)
C:/ncs/v2.7.0/zephyr/cmake/modules/zephyr_default.cmake:141 (include)
C:/ncs/v2.7.0/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:66 (include)
C:/ncs/v2.7.0/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:92 (include_boilerplate)
CMakeLists.txt:2 (find_package)

-- Configuring done
-- Generating done
CMake Warning:
Manually-specified variables were not used by the project:

DEBUG_THREAD_INFO

-- Build files have been written to: C:/Projects/<REDACTED>/build
←[92m-- west build: building application
[8/383] Generating include/generated/version.h
-- Zephyr version: 3.6.99 (C:/ncs/v2.7.0/zephyr), build: v3.6.99-ncs2
[13/383] Performing build step for 'mcuboot_subimage'
[7/259] Generating include/generated/version.h
-- Zephyr version: 3.6.99 (C:/ncs/v2.7.0/zephyr), build: v3.6.99-ncs2
[12/259] Building C object zephyr/CMakeFiles/zephyr.dir/C_/ncs/v2.7.0/nrfxlib/crypto/nrf_cc310_platform/src/nrf_cc3xx_platform_abort_zephyr.c.o[31/259] Building C object modules/mbedtls/CMakeFiles/modules__mbedtls.dir/C_/ncs/v2.7.0/modules/crypto/mbedtls/library/ssl_debug_helpers_gener[44/259] Building C object modules/hal_nordic/nrfx/CMakeFiles/modules__hal_nordic__nrfx.dir/C_/ncs/v2.7.0/modules/hal/nordic/nrfx/mdk/system_nr[46/259] Building C object modules/hal_nordic/nrfx/CMakeFiles/modules__hal_nordic__nrfx.dir/C_/ncs/v2.7.0/modules/hal/nordic/nrfx/helpers/nrfx_[48/259] Building C object modules/mbedtls/CMakeFiles/modules__mbedtls.dir/C_/ncs/v2.7.0/modules/crypto/mbedtls/library/ssl_debug_helpers_gener[49/259] Building C object modules/hal_nordic/nrfx/CMakeFiles/modules__hal_nordic__nrfx.dir/C_/ncs/v2.7.0/modules/hal/nordic/nrfx/drivers/src/n[62/259] Building C object modules/hal_nordic/nrfx/CMakeFiles/modules__hal_nordic__nrfx.dir/C_/ncs/v2.7.0/modules/hal/nordic/nrfx/helpers/nrfx_[136/259] Building ASM object zephyr/soc/soc/arm/nordic_nrf/CMakeFiles/..__modules__soc-hwmv1__soc__arm__nordic_nrf.dir/common/soc_nrf_common.S[138/259] Building C object zephyr/soc/soc/arm/nordic_nrf/CMakeFiles/..__modules__soc-hwmv1__soc__arm__nordic_nrf.dir/validate_enabled_instance[139/259] Building C object zephyr/soc/soc/arm/nordic_nrf/CMakeFiles/..__modules__soc-hwmv1__soc__arm__nordic_nrf.dir/validate_base_addresses.c[179/259] Building C object modules/mcuboot/boot/bootutil/zephyr/CMakeFiles/mcuboot_util.dir/C_/ncs/v2.7.0/bootloader/mcuboot/boot/bootutil/src[254/259] Linking C executable zephyr\zephyr_pre0.elf
FAILED: zephyr/zephyr_pre0.elf zephyr/zephyr_pre0.map C:/Projects/<REDACTED>/build/mcuboot/zephyr/zephyr_pre0.map
cmd.exe /C "cd . && C:\ncs\toolchains\ce3b5ff664\opt\zephyr-sdk\arm-zephyr-eabi\bin\arm-zephyr-eabi-gcc.exe -gdwarf-4 zephyr/CMakeFiles/zephyr_pre0.dir/misc/empty_file.c.obj -o zephyr\zephyr_pre0.elf zephyr/CMakeFiles/offsets.dir/./arch/arm/core/offsets/offsets.c.obj -fuse-ld=bfd -T zephyr/linker_zephyr_pre0.cmd -Wl,-Map=C:/Projects/<REDACTED>/build/mcuboot/zephyr/zephyr_pre0.map -Wl,--whole-archive app/libapp.a zephyr/libzephyr.a zephyr/arch/common/libarch__common.a zephyr/arch/arch/arm/core/libarch__arm__core.a zephyr/arch/arch/arm/core/cortex_m/libarch__arm__core__cortex_m.a zephyr/arch/arch/arm/core/mpu/libarch__arm__core__mpu.a zephyr/lib/libc/minimal/liblib__libc__minimal.a zephyr/lib/libc/common/liblib__libc__common.a zephyr/soc/soc/arm/nordic_nrf/lib..__modules__soc-hwmv1__soc__arm__nordic_nrf.a zephyr/drivers/clock_control/libdrivers__clock_control.a zephyr/drivers/flash/libdrivers__flash.a zephyr/drivers/pinctrl/libdrivers__pinctrl.a zephyr/drivers/timer/libdrivers__timer.a modules/nrf/lib/fprotect/lib..__nrf__lib__fprotect.a modules/nrf/drivers/hw_cc3xx/lib..__nrf__drivers__hw_cc3xx.a modules/mcuboot/boot/bootutil/zephyr/libmcuboot_util.a modules/mbedtls/libmbedTLSBase.a modules/mbedtls/libmbedTLSCrypto.a modules/mbedtls/libmbedTLSX509.a modules/mbedtls/libmodules__mbedtls.a modules/hal_nordic/nrfx/libmodules__hal_nordic__nrfx.a -Wl,--no-whole-archive zephyr/kernel/libkernel.a -L"c:/ncs/toolchains/ce3b5ff664/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/thumb/v7e-m/nofp" -LC:/Projects/<REDACTED>/build/mcuboot/zephyr -lgcc zephyr/arch/common/libisr_tables.a modules/mbedtls/libmbedTLSBase.a modules/mbedtls/libmbedTLSCrypto.a modules/mbedtls/libmbedTLSX509.a -mcpu=cortex-m4 -mthumb -mabi=aapcs -mfp16-format=ieee -Wl,--gc-sections -Wl,--build-id=none -Wl,--sort-common=descending -Wl,--sort-section=alignment -Wl,-u,_OffsetAbsSyms -Wl,-u,_ConfigAbsSyms -nostdlib -static -Wl,-X -Wl,-N -Wl,--orphan-handling=warn -Wl,-no-pie C:/ncs/v2.7.0/nrfxlib/crypto/nrf_cc310_platform/lib/cortex-m4/soft-float/no-interrupts/libnrf_cc310_platform_0.9.19.a && cmd.exe /C "cd /D C:\Projects\<REDACTED>\build\mcuboot\zephyr && C:\ncs\toolchains\ce3b5ff664\opt\bin\cmake.exe -E true""c:/ncs/toolchains/ce3b5ff664/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/../../../../arm-zephyr-eabi/bin/ld.bfd.exe: zephyr\zephyr_pre0.elf section `rodata' will not fit in region `FLASH'
c:/ncs/toolchains/ce3b5ff664/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/../../../../arm-zephyr-eabi/bin/ld.bfd.exe: region `FLASH' overflowed by 680 bytes
collect2.exe: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.
[56/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[58/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[59/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[60/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[61/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[62/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[63/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[64/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[65/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[66/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[67/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[68/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[70/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[71/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[73/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[74/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[77/383] Building C object CMakeFiles/app.dir/src/<REDACTED>.c.obj
[366/383] Linking C executable zephyr\zephyr_pre0.elf
FAILED: modules/mcuboot/mcuboot_subimage-prefix/src/mcuboot_subimage-stamp/mcuboot_subimage-build mcuboot/zephyr/zephyr.hex mcuboot/zephyr/zephyr.elf C:/Projects/<REDACTED>/build/modules/mcuboot/mcuboot_subimage-prefix/src/mcuboot_subimage-stamp/mcuboot_subimage-build C:/Projects/<REDACTED>/build/mcuboot/zephyr/zephyr.hex C:/Projects/<REDACTED>/build/mcuboot/zephyr/zephyr.elf
cmd.exe /C "cd /D C:\Projects\<REDACTED>\build\mcuboot && C:\ncs\toolchains\ce3b5ff664\opt\bin\cmake.exe --build . --"
[368/383] Linking C executable zephyr\zephyr_pre0.elf
ninja: build stopped: subcommand failed.
FATAL ERROR: command exited with status 1: 'C:\ncs\toolchains\ce3b5ff664\opt\bin\cmake.EXE' --build 'c:\Projects\<REDACTED>\build'

* The terminal process terminated with exit code: 1.
* Terminal will be reused by tasks, press any key to close it.

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Amanda Hsieh — Thu, 29 Jan 2026 17:26:05 GMT

[quote user="Will_20241202"]I'm not (yet) using sysbuild. [/quote]

Then you have to figure out why changing to 0x7000 in child_image\mcuboot\prj.conf had no effect. Check if there are any config conflicts or warnings in the build log.

Do other configs in child_image\mcuboot\prj.conf take effect in build\mcuboot\zephyr\.config?

You can refer to bootloader\mcuboot\boot\zephyr\prj_minimal.conf for your child_image\mcuboot\prj.conf to reduce the mcuboot size.

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Will_20241202 — Wed, 28 Jan 2026 18:46:23 GMT

I'm not (yet) using sysbuild. I'm trying to step one change at a time from a very old SDK (v2.4.0) to a very new one (v3.2.1) and only make small incremental changes along the way so that detecting/fixing problems are manageable. Once I get this variant building, I plan to migrate from HWMv1 to HWMv2 (still on SDK v2.7.0), and after that from the child_image flavor to sysbuild. However I don't want to add more variables to the mix until this set of issues is resolved.

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Amanda Hsieh — Wed, 28 Jan 2026 18:41:32 GMT

Are you using sysbuild? If so, you can try to add to sysbuild/mcuboot/prj.conf.

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Will_20241202 — Wed, 28 Jan 2026 18:11:19 GMT

Changing to 0x7000 (in all four files) had no effect. The other three files auto-regenerated back to 0x6000 and the build still failed because it was too big by 680 bytes.

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Amanda Hsieh — Wed, 28 Jan 2026 17:51:29 GMT

Try to set CONFIG_PM_PARTITION_SIZE_MCUBOOT=0x7000 (must align to 0x1000) in the child_image\mcuboot\prj.conf.

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Will_20241202 — Wed, 28 Jan 2026 15:50:11 GMT

That symbol appears 4 times in all (human readable) files in the project directory:

child_image\mcuboot\prj.conf
build\mcuboot\zephyr\.config
build\mcuboot\zephyr\include\generated\autoconf.h
build\mcuboot\zephyr\misc\generated\configs.c

I tried changing it in all four (even though the last 3 are auto-generated) from 0x6000 to 0x6300 and nothing changed. Same error message about being too big by 680 bytes. Curiously, the last 3 files auto-updated back to the 0x6000 value. Which leads me to think the first file doesn't actually do anything. Is there some other place that this is controlled?

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Amanda Hsieh — Wed, 28 Jan 2026 15:22:24 GMT

You can check the CONFIG_PM_PARTITION_SIZE_MCUBOOT value in the .config file under build/mcuboot/zephyr and try to increase it.

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Will_20241202 — Wed, 28 Jan 2026 14:29:51 GMT

I tried removing giant swathes of code from my project (both functions and static variables) and it still says I am exactly 680 bytes too big... Which leads me to believe the problem lies outside of my code, and likely in the bootloader. Is there an easy way to check how big the bootloader is and how big the container that it is being put into is?

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Will_20241202 — Wed, 28 Jan 2026 14:29:06 GMT

Hi Amanda,

I have looked through that guide and it isn't really helpful in my situation. I'm trying to figure out why the exact same code with the exact same build options will build just fine using SDK 2.6.1 but runs out of space trying to build under SDK v2.7.0

Clearly something changed between the two versions but I'm having trouble finding documentation on exactly what, or how to figure it out.

RE: Failing to build; region `FLASH' overflowed by 680 bytes

Amanda Hsieh — Fri, 23 Jan 2026 14:50:24 GMT

Hi,

Please refer to Memory footprint optimization to reduce the memory size. You can also compare the .config under build/zephry (or build/app/zephyr) to find the differences if you don't modify the configs or anything.

Regards,
Amanda H.