applications: nrf_desktop: enable LTO for the MCUboot on nRF54L15 DK

Enable Link Time optimization (LTO) for the MCUboot image and the
nRF54L15 DK target in the nRF Desktop application.

Signed-off-by: Kamil Piszczek <[email protected]>

Author: kapi-no

applications/nrf_desktop/configuration/nrf54l15dk_nrf54l15_cpuapp/images/mcuboot/prj.conf

@@ -35,3 +35,7 @@ CONFIG_MINIMAL_LIBC=y
 
 # Improve debugging experience by disabling reset on fatal error
 CONFIG_RESET_ON_FATAL_ERROR=n
+
+# Activate LTO
+CONFIG_LTO=y
+CONFIG_ISR_TABLES_LOCAL_DECLARATION=y

applications/nrf_desktop/configuration/nrf54l15dk_nrf54l15_cpuapp/images/mcuboot/prj_fast_pair.conf

@@ -35,3 +35,7 @@ CONFIG_MINIMAL_LIBC=y
 
 # Improve debugging experience by disabling reset on fatal error
 CONFIG_RESET_ON_FATAL_ERROR=n
+
+# Activate LTO
+CONFIG_LTO=y
+CONFIG_ISR_TABLES_LOCAL_DECLARATION=y

applications/nrf_desktop/configuration/nrf54l15dk_nrf54l15_cpuapp/images/mcuboot/prj_keyboard.conf

@@ -35,3 +35,7 @@ CONFIG_MINIMAL_LIBC=y
 
 # Improve debugging experience by disabling reset on fatal error
 CONFIG_RESET_ON_FATAL_ERROR=n
+
+# Activate LTO
+CONFIG_LTO=y
+CONFIG_ISR_TABLES_LOCAL_DECLARATION=y

applications/nrf_desktop/configuration/nrf54l15dk_nrf54l15_cpuapp/images/mcuboot/prj_release.conf

@@ -34,3 +34,7 @@ CONFIG_USE_SEGGER_RTT=n
 
 # Use minimal C library instead of the Picolib
 CONFIG_MINIMAL_LIBC=y
+
+# Activate LTO
+CONFIG_LTO=y
+CONFIG_ISR_TABLES_LOCAL_DECLARATION=y

doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst

@@ -343,6 +343,7 @@ nRF Desktop
   * All build configurations with the DFU over MCUmgr support to require encryption for operations on the Bluetooth GATT SMP service (see the :kconfig:option:`CONFIG_MCUMGR_TRANSPORT_BT_PERM_RW_ENCRYPT` Kconfig option).
     The Bluetooth pairing procedure of the unpaired Bluetooth peers must now be performed before the DFU operation.
   * The :ref:`nrf_desktop_dfu_mcumgr` to enable the MCUmgr handler that is used to report the bootloader information (see the :kconfig:option:`CONFIG_MCUMGR_GRP_OS_BOOTLOADER_INFO` Kconfig option).
+  * The MCUboot image configurations for the :ref:`zephyr:nrf54l15dk_nrf54l15` board to enable Link Time Optimization (LTO) (see the :kconfig:option:`CONFIG_LTO` Kconfig option) and reduce the memory footprint of the bootloader.
 
 nRF Machine Learning (Edge Impulse)
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