ACK: [PATCH 1/1] UBUNTU: SAUCE: arm64: dtbs: Add symbols when compiling dtb

[Colin Ian King]

On 17/07/18 12:51, Paolo Pisati wrote:
> BugLink: http://bugs.launchpad.net/bugs/1782121
> 
> Overlay files are dtb fragments that, upon boot, patch the main dtb
> board file to enable Raspberry Pi hardware extension (commonly known as
> Raspberry HATs) to work.
> 
> This mechanism works fine for the bionic/raspi2 kernel, but it didn't
> work for the raspi2 arm64 variant since our dtb files are missing
> symbols there.
> 
> This patch instruct the device tree compiler to add symbols to the dtb
> files during the 'make dtbs' target, and fix the overlay patching
> mechanism for bionic/raspi2 arm64.
> 
> The resulting increase in size is negligible (~30kb for the whole kernel
> package).
> 
> Signed-off-by: Paolo Pisati <paolo.pisati at canonical.com>
> ---
>  arch/arm64/boot/dts/broadcom/Makefile | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/broadcom/Makefile b/arch/arm64/boot/dts/broadcom/Makefile
> index 11180bba170b..217a0dc28ed8 100644
> --- a/arch/arm64/boot/dts/broadcom/Makefile
> +++ b/arch/arm64/boot/dts/broadcom/Makefile
> @@ -4,5 +4,10 @@ dtb-$(CONFIG_ARCH_BCM2709) += bcm2710-rpi-3-b.dtb
>  dtb-$(CONFIG_ARCH_BCM2835) += bcm2710-rpi-3-b.dtb
>  dtb-$(CONFIG_ARCH_BCM2835) += bcm2710-rpi-3-b-plus.dtb
>  
> +# Enable fixups to support overlays on BCM2835 platforms
> +ifeq ($(CONFIG_ARCH_BCM2835),y)
> +	DTC_FLAGS ?= -@
> +endif
> +
>  subdir-y	+= northstar2
>  subdir-y	+= stingray
> 

Seems like a reasonable workaround to me. Nice find.

Acked-by: Colin Ian King <colin.king at canonical.com>