[PATCH v2 00/17] Apply device tree overlays to kernel tree

[Sascha Hauer]

With this series barebox gains the capability to apply device tree
overlays to the kernel device tree before starting the kernel with it.
Which overlays are applied can be controlled with a set of globavars,
for details see the documentation patch in this series.

The particular usecase we have in mind with this series is that the
rootfs has a bunch of device tree overlays in it which shall be applied
based on bootloader knowledge. For example information of the exact
board type might be stored in an EEPROM. Based on that information
barebox can now pick the right overlays for that board from the rootfs.
Interpreting the EEPROM content is board specific and not part of this
series, for now the the globalvars must be set manually.

The previous series had the problem that each time a of_fix_tree() was
executed all firmwares were reloaded. This is solved in this series.
Instead of loading the firmware files directly when applying an overlay,
they are collected to a list. Only when we are booting the Kernel we
explicitly load the firmwares we have previously collected.

Changes since v1:

- Do not (re-)load firmware on each of_fix_tree()
- handle empty strings returned from strsep gracefully
- Drop -S option from of_overlay command instead of ignoring it

Sascha Hauer (17):
  fdt: Check blob size during unflattening
  firmware: make device_node argument non const
  libbb: Add find_path function
  firmware: consolidate ifdefs
  firmware: Add search path
  firmware: Fix device_node matching
  firmware: recognize by reproducible name
  blspec: Set firmware searchpath
  overlay: only apply compatible trees
  overlay: Add of_overlay_apply_file()
  firmware: Load from global search path
  blspec: Rework firmware load
  of_overlay: apply overlays during booting
  blspec: Apply overlays from rootfs
  doc: devicetree: Refer to internal device tree also as live tree
  Documentation: Add documentation for device tree overlays
  of_firmware: Fix handling of firmware-name property

 Documentation/user/devicetree.rst         |  39 +++++-
 arch/arm/boards/qemu-virt/board.c         |   4 +-
 arch/arm/boards/raspberry-pi/rpi-common.c |   2 +-
 arch/arm/boards/webasto-ccbv2/board.c     |   2 +-
 arch/arm/lib32/bootm.c                    |   6 +-
 arch/arm/lib32/bootu.c                    |   5 +-
 arch/arm/lib32/bootz.c                    |   3 +
 arch/arm/lib64/armlinux.c                 |   4 +
 arch/kvx/lib/bootm.c                      |   6 +
 arch/mips/lib/bootm.c                     |   4 +
 arch/powerpc/lib/ppclinux.c               |   4 +
 arch/riscv/lib/bootm.c                    |   5 +
 commands/of_diff.c                        |   2 +-
 commands/of_display_timings.c             |   2 +-
 commands/of_dump.c                        |   4 +-
 commands/of_overlay.c                     |  34 +----
 commands/oftree.c                         |   2 +-
 common/blspec.c                           | 102 ++++++---------
 common/bootm.c                            |   4 +-
 common/efi/efi.c                          |   2 +-
 common/firmware.c                         |  59 ++++++++-
 common/image-fit.c                        |   2 +-
 common/oftree.c                           |   2 +
 common/state/backend_format_dtb.c         |   2 +-
 drivers/firmware/altera_serial.c          |   1 +
 drivers/firmware/socfpga.c                |   2 +
 drivers/firmware/zynqmp-fpga.c            |   2 +
 drivers/of/base.c                         |   2 +-
 drivers/of/fdt.c                          |  17 ++-
 drivers/of/of_firmware.c                  | 137 ++++++++++++-------
 drivers/of/overlay.c                      | 152 ++++++++++++++++++++++
 include/firmware.h                        |  26 ++--
 include/libbb.h                           |   4 +-
 include/of.h                              |  45 ++++++-
 lib/libbb.c                               |  58 ++++++---
 35 files changed, 552 insertions(+), 195 deletions(-)

-- 
2.29.2