This repo implements support for developing Tiano platform device drivers compliant to the UEFI Driver Model, by performing driver binding and configuration using a Devicetree. Such a Devicetree is typically either passed to UEFI by higher-privileged firmware.

Advantages:

• Allows UEFI developers to fully embrace modularity and code reuse.
• Facilitates development of complex (graphics, NIC, etc) drivers.
• Enables a single firmware binary to work across SoC revisions and board designs.

FdtBusPkg consists of FdtBusDxe, a bus driver, and a number of examples drivers and libraries for demoing with the RISC-V OVMF firmware. FdtBusDxe is responsible for enumerating DT controllers based on Devicetree nodes, and implementing EFI_DT_IO_PROTOCOL for basic operations on such controllers, such as device property access, register I/O, DMA buffer handling and child device enumeration.

See further documentation:

• FdtBusPkg Documentation Style and Terms Definitions
• Devicetree Device Drivers
• EFI Devicetree I/O Protocol
• EFI Devicetree Interrupt Protocol
• FdtBusPkg-Specific Devicetree Bindings
• FdtBusDxe Overview
• Another README for Developers

FdtBusPkg components can be used on any architecture, but have been developed and tested with RISC-V. They should be reusable out of the box on AArch64 platforms as well, barring any missing dependencies.

Note: this is Devicetree being used internally by UEFI. There is no relation to using Devicetree as possible mechanism of describing hardware configuration to an OS.

See the presentation video and slides from the UEFI Fall 2023 Developers Conference and Plugfest. Also see the short demo video published February, 2024.

To build RISC-V OVMF firmware enabled with FdtBusPkg components:

    $ git clone https://github.com/tianocore/edk2.git
    $ cd edk2
    $ git submodule add https://github.com/intel/FdtBusPkg
    $ git submodule update --init --recursive
    $ . edksetup.sh
    $ git am FdtBusPkg/Docs/edk2-patches/*
    $ git am FdtBusPkg/Docs/ovmf-patches/*
    $ export GCC_RISCV64_PREFIX=... (if you are on a non-RISCV64 system)
    $ build -a RISCV64  -p OvmfPkg/RiscVVirt/RiscVVirtQemu.dsc -t GCC -b DEBUG

See the README for Developers for more directions.

FdtBusPkg is licensed under the BSD-2-Clause-Patent license (just like Tiano).

Intel is committed to rapidly addressing security vulnerabilities affecting our customers and providing clear guidance on the solution, impact, severity and mitigation.

Please report any security vulnerabilities in this project utilizing the guidelines here.

This is a RISE Project under the Firmware WG. See the project wiki page.

Contributions are welcome. Please raise issues and pull requests.

Please see the policy on contributions and our Code of Conduct.