quand y'en a marre y'a malabar
we got a shit-load of guides regarding netbsd bootstrap and boot – and to be honest, it’s a bit of a mess!
bsd/ext2fs | bsd/ext2fs-boot | xen guest | kvm guest
https://man.netbsd.org/x86/mbr.8
https://man.netbsd.org/x86/boot.8
https://man.netbsd.org/x86/boot_console.8
https://man.netbsd.org/installboot.8
https://man.netbsd.org/x86/console.4
https://www.gnu.org/software/grub/manual/grub/html_node/NetBSD.html
https://www.gnu.org/software/grub/manual/grub/html_node/BIOS-installation.html
https://www.gnu.org/software/grub/manual/grub/html_node/Installing-GRUB-using-grub_002dinstall.html
https://forum.level1techs.com/t/guide-serial-console-server-using-netbsd-on-an-arm-sbc/148658
https://unix.stackexchange.com/questions/9974/netbsd-serial-port-gateway
https://unix.stackexchange.com/questions/197370/grub-install-whats-the-root-directory
https://unix.stackexchange.com/questions/683709/command-to-install-grub2-on-a-bios-boot-partition
https://www.thegeekdiary.com/grub-install-command-options/
https://kimmo.suominen.com/blog/2020/04/serial-console-for-netbsd/