[PATCH v5 00/26] fdt: Make OF_BOARD a boolean option
Simon Glass
sjg at chromium.org
Wed Oct 27 16:08:19 CEST 2021
Hi François,
On Tue, 26 Oct 2021 at 00:07, François Ozog <francois.ozog at linaro.org> wrote:
>
> Hi Simon
>
> Position unchanged on this series: adding fake dts for boards that generate their device tree in the dts directory is not good. If you have them in documentation the it is acceptable.
I think we are going to have to disagree on this one. I actually used
the qemu one in testing/development recently. We have to have a way to
develop in-tree with U-Boot. It does not impinge on any of your use
cases, so far as I know.
But trying to do any driver / core work for a board where you don't
have the devicetree is currently not possible. The devicetree is a
core component and being unable to modify it is simply not practical.
We are talking here about an option that can be enabled or disabled.
In my case I am able to disable it locally and do my development work.
BTW I've got the bloblist handoff working with a devicetree inside it,
for qemu_arm. I need to try it on a real board to figure out what the
difference is.
Regards,
Simon
>
>
> Cheers
>
> FF
>
> Le mar. 26 oct. 2021 à 02:24, Simon Glass <sjg at chromium.org> a écrit :
>>
>> 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.
>>
>> Note: This breaks the qemu-riscv64_spl test, which still needs
>> investigation.
>>
>> [1] https://patchwork.ozlabs.org/project/uboot/patch/20210919215111.3830278-3-sjg@chromium.org/
>>
>> Changes in v5:
>> - Bring into the OF_BOARD series
>> - Rebase to master and drop mention of OF_PRIOR_STAGE, since removed
>> - Refer to the 'control' DTB in the first paragraph
>> - Use QEMU instead of qemu
>> - Merge RISC-V and ARM patches since they are similar
>> - Add new patches to clean up fdtdec_setup() and surrounds
>>
>> Changes in v3:
>> - Clarify the 'bug' refered to at the top
>> - Reword 'This means that there' paragraph to explain U-Boot-specific things
>> - Move to doc/develop/devicetree now that OF_CONTROL is in the docs
>>
>> Changes in v2:
>> - Fix typos per Sean (thank you!) and a few others
>> - Add a 'Use of U-Boot /config node' section
>> - Drop mention of dm-verity since that actually uses the kernel cmdline
>> - Explain that OF_BOARD will still work after these changes (in
>> 'Once this bug is fixed...' paragraph)
>> - Expand a bit on the reason why the 'Current situation' is bad
>> - Clarify in a second place that Linux and U-Boot use the same devicetree
>> in 'To be clear, while U-Boot...'
>> - Expand on why we should have rules for other projects in
>> 'Devicetree in another project'
>> - Add a comment as to why devicetree in U-Boot is not 'bad design'
>> - Reword 'in-tree U-Boot devicetree' to 'devicetree source in U-Boot'
>> - Rewrite 'Devicetree generated on-the-fly in another project' to cover
>> points raised on v1
>> - Add 'Why does U-Boot have its nodes and properties?'
>> - Add 'Why not have two devicetrees?'
>>
>> Ilias Apalodimas (1):
>> sandbox: Remove OF_HOSTFILE
>>
>> Simon Glass (25):
>> doc: Add documentation about devicetree usage
>> arm: qemu: Mention -nographic in the docs
>> arm: riscv: qemu: Explain how to extract the generated dt
>> arm: qemu: Add a devicetree file for qemu_arm
>> arm: qemu: Add a devicetree file for qemu_arm64
>> riscv: qemu: Add devicetree files for qemu_riscv32/64
>> arm: rpi: Add a devicetree file for rpi_4
>> arm: vexpress: Add a devicetree file for juno
>> arm: xenguest_arm64: Add a fake devicetree file
>> arm: octeontx: Add a fake devicetree file
>> arm: xilinx_versal_virt: Add a devicetree file
>> arm: bcm7xxx: Add a devicetree file
>> arm: qemu-ppce500: Add a devicetree file
>> arm: highbank: Add a fake devicetree file
>> fdt: Make OF_BOARD a bool option
>> Drop CONFIG_BINMAN_STANDALONE_FDT
>> doc: Update info on devicetree update
>> fdt: Move MULTI_DTB_FIT handling out of fdtdec_setup()
>> fdt: Drop #ifdefs with MULTI_DTB_FIT
>> fdt: Drop CONFIG_SPL_BUILD check in fdtdec_setup()
>> fdt: Drop #ifdef around board_fdt_blob_setup()
>> fdt: Use if() for fdtcontroladdr check
>> fdt: Drop OF_CONTROL check in fdtdec_setup()
>> fdt: Drop remaining preprocessor macros in fdtdec_setup()
>> fdt: Don't call board_fdt_blob_setup() without OF_BOARD
>>
>> Makefile | 7 +-
>> arch/arm/dts/Makefile | 20 +-
>> arch/arm/dts/bcm2711-rpi-4-b.dts | 1958 +++++++++++++++++++++
>> arch/arm/dts/bcm7xxx.dts | 15 +
>> arch/arm/dts/highbank.dts | 14 +
>> arch/arm/dts/juno-r2.dts | 1038 +++++++++++
>> arch/arm/dts/octeontx.dts | 14 +
>> arch/arm/dts/qemu-arm.dts | 402 +++++
>> arch/arm/dts/qemu-arm64.dts | 381 ++++
>> arch/arm/dts/xenguest-arm64.dts | 15 +
>> arch/arm/dts/xilinx-versal-virt.dts | 307 ++++
>> arch/powerpc/dts/Makefile | 1 +
>> arch/powerpc/dts/qemu-ppce500.dts | 264 +++
>> arch/riscv/dts/Makefile | 2 +-
>> arch/riscv/dts/qemu-virt.dts | 8 -
>> arch/riscv/dts/qemu-virt32.dts | 217 +++
>> arch/riscv/dts/qemu-virt64.dts | 217 +++
>> arch/sandbox/cpu/cpu.c | 21 +-
>> arch/sandbox/include/asm/u-boot-sandbox.h | 8 -
>> configs/bcm7260_defconfig | 1 +
>> configs/bcm7445_defconfig | 1 +
>> configs/highbank_defconfig | 2 +-
>> configs/octeontx2_95xx_defconfig | 1 +
>> configs/octeontx2_96xx_defconfig | 1 +
>> configs/octeontx_81xx_defconfig | 1 +
>> configs/octeontx_83xx_defconfig | 1 +
>> configs/qemu-ppce500_defconfig | 2 +
>> configs/qemu-riscv32_defconfig | 1 +
>> configs/qemu-riscv32_smode_defconfig | 1 +
>> configs/qemu-riscv32_spl_defconfig | 4 +-
>> configs/qemu-riscv64_defconfig | 1 +
>> configs/qemu-riscv64_smode_defconfig | 1 +
>> configs/qemu-riscv64_spl_defconfig | 3 +-
>> configs/qemu_arm64_defconfig | 1 +
>> configs/qemu_arm_defconfig | 1 +
>> configs/rpi_4_32b_defconfig | 1 +
>> configs/rpi_4_defconfig | 1 +
>> configs/rpi_arm64_defconfig | 1 +
>> configs/sandbox64_defconfig | 2 +-
>> configs/sandbox_defconfig | 2 +-
>> configs/sandbox_flattree_defconfig | 2 +-
>> configs/sandbox_noinst_defconfig | 2 +-
>> configs/sandbox_spl_defconfig | 2 +-
>> configs/tools-only_defconfig | 2 +-
>> configs/vexpress_aemv8a_juno_defconfig | 1 +
>> configs/xenguest_arm64_defconfig | 1 +
>> configs/xilinx_versal_virt_defconfig | 1 +
>> doc/board/emulation/qemu-arm.rst | 10 +-
>> doc/board/emulation/qemu-riscv.rst | 3 +
>> doc/develop/devicetree/control.rst | 7 +-
>> doc/develop/devicetree/dt_qemu.rst | 48 +
>> doc/develop/devicetree/dt_update.rst | 498 ++++++
>> doc/develop/devicetree/index.rst | 2 +
>> dts/Kconfig | 37 +-
>> include/asm-generic/global_data.h | 8 +
>> include/fdtdec.h | 21 +-
>> lib/fdtdec.c | 116 +-
>> scripts/Makefile.spl | 4 +-
>> tools/binman/binman.rst | 20 -
>> 59 files changed, 5560 insertions(+), 164 deletions(-)
>> create mode 100644 arch/arm/dts/bcm2711-rpi-4-b.dts
>> create mode 100644 arch/arm/dts/bcm7xxx.dts
>> create mode 100644 arch/arm/dts/highbank.dts
>> create mode 100644 arch/arm/dts/juno-r2.dts
>> create mode 100644 arch/arm/dts/octeontx.dts
>> create mode 100644 arch/arm/dts/qemu-arm.dts
>> create mode 100644 arch/arm/dts/qemu-arm64.dts
>> create mode 100644 arch/arm/dts/xenguest-arm64.dts
>> create mode 100644 arch/arm/dts/xilinx-versal-virt.dts
>> create mode 100644 arch/powerpc/dts/qemu-ppce500.dts
>> delete mode 100644 arch/riscv/dts/qemu-virt.dts
>> create mode 100644 arch/riscv/dts/qemu-virt32.dts
>> create mode 100644 arch/riscv/dts/qemu-virt64.dts
>> create mode 100644 doc/develop/devicetree/dt_qemu.rst
>> create mode 100644 doc/develop/devicetree/dt_update.rst
>>
>> --
>> 2.33.0.1079.g6e70778dc9-goog
>>
> --
> François-Frédéric Ozog | Director Business Development
> T: +33.67221.6485
> francois.ozog at linaro.org | Skype: ffozog
>
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