Moving /boot, how to update grub to find new location /boot/grub2/i386-pc/{core,boot}.img

Grub2 systems hard-code the location of stage2 files. This info is stored in the bootloader partition. I understand that grub-install will write this and more. My question is how does grub2-install figure out where the /boot directory (it's own partition) happens to be. grub-mkconfig can figure this out, however, it does not appear that grub-install invokes grub-mkconfig. I'd really like an in-depth explanation of how this is figured out. Bottom line question is: "What is proper way to update the bootloader code in the mbr/bios-boot partition when location of /boot changes"? Pointers to official documentation or wikis would be appreciated.