> On Mon, Aug 16, 2021 at 06:03:52AM +0000, Hongbo Wang wrote: > > > I was going to suggest as an alternative to define a device tree > > > overlay file with the changes in the CPU port assignment, instead of > > > defining a wholly new DTS for the LS1028A reference design board. > > > But I am pretty sure that it is not possible to specify a > > > /delete-property/ inside a device tree overlay file, so that won't actually > work. > > > > hi Vladimir, > > > > if don't specify "/delete-property/" in this dts file, the > > corresponding dtb will not work well, so I add it to delete 'ethernet' property > from mscc_felix_port4 explicitly. > > Judging by the reply, I am not actually sure you've understood what has been > said. > > I said: > > There is an option to create a device tree overlay: > > https://www.kernel.org/doc/html/latest/devicetree/overlay-notes.html > > We use these for the riser cards on the LS1028A-QDS boards. > > https://source.codeaurora.org/external/qoriq/qoriq-components/linux/tree/ar > ch/arm64/boot/dts/freescale/fsl-ls1028a-qds-13bb.dts?h=LSDK-20.12-V5.4 > > They are included as usual in a U-Boot ITB file: > > / { > images { > /* Base DTB */ > ls1028aqds-dtb { > description = "ls1028aqds-dtb"; > data = > /incbin/("arch/arm64/boot/dts/freescale/fsl-ls1028a-qds.dtb"); > type = "flat_dt"; > arch = "arm64"; > os = "linux"; > compression = "none"; > load = <0x90000000>; > hash@1 { > algo = "crc32"; > }; > }; > /* Overlay */ > fdt@ls1028aqds-13bb { > description = "ls1028aqds-13bb"; > data = > /incbin/("arch/arm64/boot/dts/freescale/fsl-ls1028a-qds-13bb.dtb"); > type = "flat_dt"; > arch = "arm64"; > load = <0x90010000>; > }; > }; > }; > > In U-Boot, you apply the overlay as following: > > tftp $kernel_addr_r boot.itb && bootm > $kernel_addr_r#ls1028aqds#ls1028aqds-13bb > > It would have been nice to have a similar device tree overlay that changes the > DSA master from eno2 to eno3, and for that overlay to be able to be applied > (or not) from U-Boot. > > But it's _not_ possible, because you cannot put the /delete-property/ (that you > need to have) in the .dtbo file. Or if you put it, it will not delete the property > from the base dtb. > > That's all I said. thanks for the detailed explanation, I have got your point. thanks, hongbo
