Hi Tom, On Fri, 3 Dec 2021 at 07:55, Tom Rini <tr...@konsulko.com> wrote: > > 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).
That code is the penultimate patch ("fdt: Drop remaining preprocessor macros in fdtdec_setup()"). Did that patch apply OK? It is based on -next and is at dm/ofb-working if you want to compare. > > 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? Yes, so long as OF_BOARD is enabled, which it is in this series. This is basically the same as the situation with rpi3, except it uses OF_EMBED (need to fix...) If we get as far as the std passage stuff then it will print out the source of the DT when it starts. If you like I could move three patches into this series: f88bd6a431a (HEAD -> ofb6) dm: core: Allow getting some basic stats 8121102a004 passage: Report the devicetree source c9c791ddedf passage: Record where the devicetree came from 5a0b7505498 (dm/ofb-working, dm-public/ofb-working) fdt: Don't call board_fdt_blob_setup() without OF_BOARD Booting with rpi3 and rpi4 I get (see the "devicetree:" bit): U-Boot 2022.01-rc3-00154-gf88bd6a431a (Dec 03 2021 - 08:32:41 -0700) DRAM: 992 MiB RPI 3 Model B (0xa02082) Core: 61 devices, 11 uclasses, devicetree: embed MMC: mmc@7e202000: 0, sdhci@7e300000: 1 Loading Environment from FAT... Unable to read "uboot.env" from mmc0:1... In: serial Out: vidconsole Err: vidconsole U-Boot 2022.01-rc3-00154-gf88bd6a431a (Dec 03 2021 - 08:33:43 -0700) DRAM: 3.9 GiB RPI 4 Model B (0xc03111) Core: 197 devices, 13 uclasses, devicetree: board MMC: mmcnr@7e300000: 1, mmc@7e340000: 0 Loading Environment from FAT... Unable to read "uboot.env" from mmc0:1... In: serial Out: vidconsole Regards, Simon