[PATCH v2 0/4] efi: payload: allow extension via fragments

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

CONFIG_EXTERNAL_DTS_FRAGMENTS can't be used with the EFI payload, because
it has no internal DT at build-time and until recently not even a DT at
runtime.

This series adds the necessary bits to have this work the same on
non-EFI-payload platforms.

Changes in v2:
  - "efi: payload: ignore ESP state.dtb if device tree is populated":
    check before touching the ESP and only warn if state.dtb actually
    exists, so a built-in state no longer logs a missing file (Fabian)

  - "kbuild: dtc: introduce empty fallback device tree": build
    fallback.dtb on ARM and RISC-V only with CONFIG_EFI_PAYLOAD, so a
    fragment referencing board labels no longer breaks other builds (Anis)

  - "efi: payload: export device tree in barebox-dtb EFI variable": delete
    any existing barebox-dtb variable first, as SetVariable() won't change
    attributes and a non-volatile variable created via efivarfs would
    otherwise survive and be read instead of the exported device tree

  - "Documentation: efi: describe device tree handling": refer to the
    "Load options" section that the series this one applies on adds

  - Rebase onto the load options series instead of next

  - Link to v1: https://lore.barebox.org/barebox/20260826121640.2936023-1-a.fatoum@pengutronix.de/

Ahmad Fatoum (4):
  efi: payload: ignore ESP state.dtb if device tree is populated
  kbuild: dtc: introduce empty fallback device tree
  efi: payload: export device tree in barebox-dtb EFI variable
  Documentation: efi: describe device tree handling

 Documentation/boards/efi.rst | 76 ++++++++++++++++++++++++++++++++++--
 Documentation/user/state.rst |  5 +++
 arch/arm/dts/Makefile        |  4 ++
 arch/riscv/dts/Makefile      |  4 ++
 arch/x86/Kbuild              |  2 +
 arch/x86/dts/Makefile        |  5 +++
 common/fallback.dts          | 10 +++++
 efi/payload/boarddata.c      | 11 ------
 efi/payload/fdt.c            | 56 ++++++++++++++++++++++++++
 efi/payload/handover.c       |  2 +
 efi/payload/image.c          |  2 +
 efi/payload/init.c           | 18 +++++++++
 include/efi/payload.h        |  6 +++
 scripts/Makefile.dtbs        | 10 +++++
 14 files changed, 196 insertions(+), 15 deletions(-)
 create mode 100644 arch/x86/dts/Makefile
 create mode 100644 common/fallback.dts

-- 
2.47.3