on HaikuOS

building system components separately

to build a system component like for example add-ons/mail_daemon but not the whole Haiku, use jam -q mail_daemon

I'm going to add it to boot.ini

http://web.archive.org/web/20201031035448/http://besly.de/index.php/de/system/systemstartup/haiku-im-windows-bootmenue-einfuegen

The Linux boot loader first 512 bytes, presumably it is your bootsect.lnx, should be stored inside the directory where boot.ini is stored. [...] To boot a Linux WIndows must have the first 512 bytes of the Linux boot loader "available" inside its own filing system and in the same drive that stores its own NTLDR boot loader, so that the NTLDR can be replaced by the Linux boot loader to dual boot. https://www.techguy.org/threads/linux-and-the-boot-ini.483042/

https://arstechnica.com/civis/threads/dual-boot-win2k-and-beos-possible-how.1058272/