How to make a bootable partition from scratch?

What I want to achieve is to make a new bootable partition on my MacBook's SSD, so it should be possible to press Option key on startup and choose this partition to boot from. Why do I need that? I just successfully compiled XNU kernel from sources, found some drivers (kernel extensions), so now I want to boot this kernel and to load bash after boot process finishes. The key idea is to make a minimal Mac OS, just with command line interface. Here is the output of diskutil list:

Alexanders-MacBook-Pro:~ aperechnev$ diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *251.0 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                 Apple_APFS Container disk1         250.8 GB   disk0s2

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +250.8 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume Macintosh HD - Data     99.8 GB    disk1s1
   2:                APFS Volume Preboot                 83.8 MB    disk1s2
   3:                APFS Volume Recovery                525.5 MB   disk1s3
   4:                APFS Volume VM                      1.1 GB     disk1s4
   5:                APFS Volume Macintosh HD            10.9 GB    disk1s5

What I want to achieve first is to see the new partition as an option to boot from by pressing Option key and to get some error when I try to boot from that partition.