cmake: partition_manager: Generate images for S0/S1 to external flash

Implemented a fix in MCUBoot for NSIB + Multi-image for nRF53.

This enables partition manager and the build system to generate images
for S1 and S0 with the address of external QSPI flash. If the QSPI node
with XiP is defined in the DTS.

This is the same code used to move the application update into the
secondary slot in external flash.

Ref. NCSDK-19223

Signed-off-by: Sigvart Hovland <sigvart.hovland@nordicsemi.no>

cmake/partition_manager.cmake

@@ -453,8 +453,27 @@ if (CONFIG_SECURE_BOOT AND CONFIG_BOOTLOADER_MCUBOOT)
   # of the symbols used to generate the offset is only available as a
   # generator expression when MCUBoots cmake code exectues. This because
   # partition manager is performed as the last step in the configuration stage.
-  math(EXPR s0_offset "${PM_MCUBOOT_SECONDARY_ADDRESS} - ${PM_S0_ADDRESS}")
-  math(EXPR s1_offset "${PM_MCUBOOT_SECONDARY_ADDRESS} - ${PM_S1_ADDRESS}")
+  if(CONFIG_PM_EXTERNAL_FLASH_MCUBOOT_SECONDARY AND CONFIG_HAS_HW_NRF_QSPI)
+    if(DEFINED ext_flash_dev)
+      get_filename_component(qspi_node ${ext_flash_dev} DIRECTORY)
+    else()
+      dt_nodelabel(qspi_node NODELABEL "qspi")
+    endif()
+    if(DEFINED qspi_node)
+      dt_reg_addr(xip_addr PATH ${qspi_node} NAME qspi_mm)
+      if(NOT DEFINED xip_addr)
+        message(WARNING "\
+        Could not find memory mapped address for XIP. Generated update hex files will \
+        not have the correct base address. Hence they can not be programmed directly \
+        to the external flash")
+      endif()
+    endif()
+  else()
+    set(xip_addr 0)
+  endif()
+
+  math(EXPR s0_offset "${xip_addr} + ${PM_MCUBOOT_SECONDARY_ADDRESS} - ${PM_S0_ADDRESS}")
+  math(EXPR s1_offset "${xip_addr} + ${PM_MCUBOOT_SECONDARY_ADDRESS} - ${PM_S1_ADDRESS}")
 
   set_property(
     TARGET partition_manager