This chapter shows how to write UEFI Drivers for SCSI host controllers and UEFI Drivers for SCSI devices. SCSI drivers must follow all of the general design guidelines described in Chapter 4 of this guide. In addition, any SCSI host controllers that are PCI controllers must also follow the PCI-specific design guidelines described in Chapter 18. This chapter covers the guidelines that apply specifically to the management of SCSI host controllers, SCSI channels, and SCSI devices. SCSI drivers, especially those for RAID controllers, may include HII functionality for SCSI subsystem configuration settings. HII functionality is described in Chapter 12 of this guide.