USB sata device etc.

If you use an external usb sata storage device, I suppose bios detects it as a usb media (bootable if there is OS or EFI link installed on device) and not an additional native sata port device.  Native sata ports are those built in mobo by oem board maker.

if you use a PCIE sata controller, it is more tricky in UEFI bios.  some older model may need to have bios mod ? PCIE driver injection to detect bootable device connected to it.

Mono’s chipset sata controller normally only controls the board’s native sata ports.  A PCIE sata card has its own third party sata controller.  So how does usb sata device route its way to the board’s sata controller ?  that is what I am trying to figure out