[U-Boot] [PATCH v2 4/5] MIPS: add initial infrastructure for device-tree files

[Purna Chandra Mandal <purna.mandal@microchip.com>]

On 12/20/2015 04:13 AM, Daniel Schwierzeck wrote:
> Prepare sub-folder for device-tree files. Make support for
> device-tree on MIPS available in Kbuild/Kconfig.
>
> Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
> Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
>
>
> ---
>
> Changes in v2:
> - add arch/mips/dts to clean list in dts/Makefile
> - keep section .dtb during link in case of CONFIG_OF_EMBED
>
>  arch/Kconfig                |  1 +
>  arch/mips/config.mk         |  2 +-
>  arch/mips/dts/.gitignore    |  1 +
>  arch/mips/dts/Makefile      | 16 ++++++++++++++++
>  arch/mips/dts/skeleton.dtsi | 23 +++++++++++++++++++++++
>  dts/Makefile                |  2 +-
>  6 files changed, 43 insertions(+), 2 deletions(-)
>  create mode 100644 arch/mips/dts/.gitignore
>  create mode 100644 arch/mips/dts/Makefile
>  create mode 100644 arch/mips/dts/skeleton.dtsi
>
> diff --git a/arch/Kconfig b/arch/Kconfig
> index 1709d40..ec12013 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -55,6 +55,7 @@ config MIPS
>  	select HAVE_PRIVATE_LIBGCC
>  	select HAVE_GENERIC_BOARD
>  	select SYS_GENERIC_BOARD
> +	select SUPPORT_OF_CONTROL
>  
>  config NDS32
>  	bool "NDS32 architecture"
> diff --git a/arch/mips/config.mk b/arch/mips/config.mk
> index 415ec8a..3ebc202 100644
> --- a/arch/mips/config.mk
> +++ b/arch/mips/config.mk
> @@ -71,7 +71,7 @@ else
>  PF_ABICALLS			:= -mabicalls
>  PF_PIC				:= -fpic
>  PF_PIE				:= -pie
> -PF_OBJCOPY			:= -j .got -j .u_boot_list -j .rel.dyn -j .padding
> +PF_OBJCOPY			:= -j .got -j .u_boot_list -j .rel.dyn -j .padding -j .dtb
>  endif
>  

There is no section called '.dtb' in U-boot linker script, instead one generated by build script is named '.dtb.init.rodata'.
Unless we add '-j .dtb.init.rodata' device-tree blob will not be copied to binary.

>  PLATFORM_CPPFLAGS		+= -G 0 $(PF_ABICALLS) $(PF_PIC)
> diff --git a/arch/mips/dts/.gitignore b/arch/mips/dts/.gitignore
> new file mode 100644
> index 0000000..b60ed20
> --- /dev/null
> +++ b/arch/mips/dts/.gitignore
> @@ -0,0 +1 @@
> +*.dtb
> diff --git a/arch/mips/dts/Makefile b/arch/mips/dts/Makefile
> new file mode 100644
> index 0000000..47b6eb5
> --- /dev/null
> +++ b/arch/mips/dts/Makefile
> @@ -0,0 +1,16 @@
> +#
> +# SPDX-License-Identifier:	GPL-2.0+
> +#
> +
> +dtb-y +=
> +
> +targets += $(dtb-y)
> +
> +# Add any required device tree compiler flags here
> +DTC_FLAGS +=
> +
> +PHONY += dtbs
> +dtbs: $(addprefix $(obj)/, $(dtb-y))
> +	@:
> +
> +clean-files := *.dtb
> diff --git a/arch/mips/dts/skeleton.dtsi b/arch/mips/dts/skeleton.dtsi
> new file mode 100644
> index 0000000..24ee6c3
> --- /dev/null
> +++ b/arch/mips/dts/skeleton.dtsi
> @@ -0,0 +1,23 @@
> +/*
> + * Skeleton device tree; the bare minimum needed to boot; just include and
> + * add a compatible value.  The bootloader will typically populate the memory
> + * node.
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +
> +/ {
> +	#address-cells = <1>;
> +	#size-cells = <1>;
> +
> +	chosen {
> +	};
> +
> +	aliases {
> +	};
> +
> +	memory {
> +		device_type = "memory";
> +		reg = <0 0>;
> +	};
> +};
> diff --git a/dts/Makefile b/dts/Makefile
> index d3122aa..c4ac153 100644
> --- a/dts/Makefile
> +++ b/dts/Makefile
> @@ -45,4 +45,4 @@ dtbs: $(obj)/dt.dtb
>  clean-files := dt.dtb.S
>  
>  # Let clean descend into dts directories
> -subdir- += ../arch/arm/dts ../arch/microblaze/dts ../arch/sandbox/dts ../arch/x86/dts
> +subdir- += ../arch/arm/dts ../arch/microblaze/dts ../arch/mips/dts ../arch/sandbox/dts ../arch/x86/dts