On Thu, Dec 02, 2021 at 08:58:54AM -0700, Simon Glass wrote: > With Ilias' efforts we have dropped OF_PRIOR_STAGE and OF_HOSTFILE so > there are only three ways to obtain a devicetree: > > - OF_SEPARATE - the normal way, where the devicetree is built and > appended to U-Boot > - OF_EMBED - for development purposes, the devicetree is embedded in > the ELF file (also used for EFI) > - OF_BOARD - the board figures it out on its own > > The last one is currently set up so that no devicetree is needed at all > in the U-Boot tree. Most boards do provide one, but some don't. Some > don't even provide instructions on how to boot on the board. > > The problems with this approach are documented in another patch in this > series: "doc: Add documentation about devicetree usage" > > In practice, OF_BOARD is not really distinct from OF_SEPARATE. Any board > can obtain its devicetree at runtime, even it is has a devicetree built > in U-Boot. This is because U-Boot may be a second-stage bootloader and its > caller may have a better idea about the hardware available in the machine. > This is the case with a few QEMU boards, for example. > > So it makes no sense to have OF_BOARD as a 'choice'. It should be an > option, available with either OF_SEPARATE or OF_EMBED. > > This series makes this change, adding various missing devicetree files > (and placeholders) to make the build work. > > Note: If board maintainers are able to add their own patch to add the > files, some patches in this series can be dropped. > > It also provides a few qemu clean-ups discovered along the way. The > qemu-riscv64_spl problem is fixed.
Note that I can't run-time test this as the last patch fails to apply
and is dependent on non-trivial missing changes ("/* The devicetree is
typically appended to U-Boot */" doesn't exist at all in lib/fdtdec.c
and that's part of the unchanging context where things fail to apply).
So, here's my first bit of confusion. Today, I build for rpi_arm64 and
no dtb files are built. I run this on my Pi 3 and everything works.
With your series, I see all the dtbs have been built, and dts/dt.dtb and
u-boot.dtb have a Pi 4 dtb in them. Should this even run now?
--
Tom
signature.asc
Description: PGP signature
