Simple Firmware Interface (SFI) is developed by Intel Corporation as a lightweight method for firmware to export static tables to the operating system.
SFI has CPU, APIC, Memory Map, Idle, Frequency, M-Timer, M-RTC, OEMx, Wake Vector, I²C Device, and a SPI Device table.
SFI provides access to a standard ACPI XSDT (Extended System Description Table).
XSDT is used by SFI to prevent namespace collision between SPI and ACPI.
Linux is the first operating system with an SFI implementation.