On Fri, May 02 2025, Tom Rini <tr...@konsulko.com> wrote: > On Fri, May 02, 2025 at 01:34:33PM +0200, Bruno Leite wrote: > >> From: Bruno Leite <br...@prevas.dk> >> >> >> Currently rpi5 uses a generic rpi_arm64_defconfig file that builds rpi4 >> devicetree. Add a defconfig that is specific to the rpi5 building the >> now available upstream dts for that board. The defconfig makes use of >> defconfig including that is now available and only changes the DTS >> related config. >> >> It is also necessary to add a more specific u-boot.dtsi to rpi5, since >> due to the ARCH_BCM283X config it will try to build the >> bcm283x-u-boot.dtsi and break. > > My question is, can we not adjust rpi_arm64_defconfig to be generic > enough and not have a problem on Pi 5 due to the default device tree?
Not really. What we want is to have CONFIG_DEFAULT_DEVICE_TREE to point at the rpi5's .dts file, because we really want to build that and not some "random" dts file that doesn't have anything to do with the hardware. I know that kinda works for the setups where the .dtb built in U-Boot is not used for anything, but in our case, we really do want to use the .dtb from the U-Boot build - we inject various U-Boot specific stuff via the EXTRA_DTSI mechanism, e.g. public key for kernel verification. And due to CONFIG_SYS_SOC being bcm283x, and bcm283x-u-boot.dtsi referencing nodes that simply don't exist when building bcm2712-rpi-5-b.dts, the build breaks. Perhaps the real problem is CONFIG_SYS_SOC being bcm283x for rpi5? I don't really know why rpi4 is both bcm2711 and bcm2835 and what the difference is, but rpi5 only seems to include a bcm2712.dtsi which does not include further dtsi files. If rpi5 has nothing to do with bcm283x, then perhaps a better approach is to ensure that CONFIG_SYS_SOC is bcm2712 when building for rpi5. Something like adding a CONFIG_TARGET_RPI_5 choice and adding a 'default "bcm2712" if TARGET_RPI_5' ? Rasmus
