On 10/06/2022 09:57, Geert Uytterhoeven wrote: >> "+ cpu0: cpu@0 { >> + device_type = "cpu"; >> + compatible = "arm,cortex-a35"; >> + clocks = <&clk NPCM8XX_CLK_CPU>; >> + reg = <0x0 0x0>; >> Why do you have two address cells? A bit more complicated and not >> necessary, I think." >> the arm,cortex-a35 is 64 Bit this is why we use #address-cells = <2>; >> and therefore reg = <0x0 0x0>; > > These addresses are not addresses on the main memory bus (which > is indeed 64-bit), but on the logical CPU bus. > Now, Documentation/devicetree/bindings/arm/cpus.yaml says you can > have #address-cells = <2> if you have non-zero MPIDR_EL1 high bits. > Thanks Tomer and Geert for explanation. OK for me. Best regards, Krzysztof