Issues migrating to sysbuild

[CktDesigner]

I have a custom board (nrf52840) project that compiles successfully with SDK  2.7.0 using the "system default" build configuration.

I'm attempting to migrate to the "newer" sysbuild build system and am having some issues:

1. I first attempted to jump to 2.9.0 (both SDK and tools), but it failed trying to compile nrfx_flag32_allocator.c (error says it can't find nrfx_flag32_allocator.c.obj.d).   Is there some different configuration statement required for sysbuild that includes this helper function file?

2. I then decided to attempt using sysbuild with 2.8.0 and got the same error.

3. So I tried to compile 2.7.0 using sysbuild and still got the same error.   Remember that 2.7.0 compiles successfully with "No sysbuild".

4. Then I tried to compile using 2.9.0, but specifying No sysbuild.   This fails as well, but for a different reason: zephyr\zephyr_pre0.elf section `text' will not fit in region `FLASH'  and an undefined reference to '__device_dts_ord_119'.      

The regions.yml and paritions.yml are the same for all three versions.

I'm using the same .dts file for the custom board and partition manager file in all build attempts.  

I think I was successful at converting my .dts to the version 2 HW format, as the warning no longer appears.

Where can I start to look?

Thanks!

[CktDesigner]

More info relating to "point 4" above.   I was able to resolve the memory issue by editing the partition manager file.   But the undefined reference message changed to __device_dts_ord_116.      The  devicetree_generated.h file seems to indicate that index 116 is the bt_hci_sdc   

Is there some new CONFIG statement that is needed for this?

Thanks!