[PATCH 1/2] Makefile: Add environment variable DEVICE_TREE to header

[Simon Glass <sjg@chromium.org>]

Hi Michal,

On Tue, 18 Feb 2020 at 09:02, Michal Simek <michal.simek@xilinx.com> wrote:
>
> Users have option to overwrite default device tree
> (CONFIG_DEFAULT_DEVICE_TREE) via environment variable DEVICE_TREE.
>
> Feature has been added long time ago by commit 74de8c9a1672
> ("dts/Makefile: Build the user specified dts") for a little bit different
> reason.
>
> But this variable can be also used for different purpose like choosing
> proper configuration from FIT image in SPL.
> And this is the functionality I would like to use on Xilinx Zynq devices
> that current u-boot.img can be composed in the same way based on OF_LIST
> and different configuration is taken based on platform specific SPL.
> SPL requires low level ps7_init_gpl configuration that's why different
> boards require different SPL with fixed board_fit_config_name_match().
>
> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
> ---
>
> I have done it in this way but maybe there is any smarter way how this can
> be done. Also macro name can change if you want.

Can you please add a bit of documentation to doc/README.fdt-control ?

> ---
>  Makefile                 | 14 +++++++++++++-
>  arch/arm/mach-zynq/spl.c |  8 ++++++--
>  2 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 0af89e0a7881..15f7cce445f6 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -483,6 +483,7 @@ endif
>  version_h := include/generated/version_autogenerated.h
>  timestamp_h := include/generated/timestamp_autogenerated.h
>  defaultenv_h := include/generated/defaultenv_autogenerated.h
> +dt_h := include/generated/dt.h
>
>  no-dot-config-targets := clean clobber mrproper distclean \
>                          help %docs check% coccicheck \
> @@ -1768,7 +1769,7 @@ endif
>  # prepare2 creates a makefile if using a separate output directory
>  prepare2: prepare3 outputmakefile cfg
>
> -prepare1: prepare2 $(version_h) $(timestamp_h) \
> +prepare1: prepare2 $(version_h) $(timestamp_h) $(dt_h) \
>                     include/config/auto.conf
>  ifeq ($(wildcard $(LDSCRIPT)),)
>         @echo >&2 "  Could not find linker script."
> @@ -1834,12 +1835,23 @@ define filechk_defaultenv.h
>          xxd -i ; echo ", 0x00" ; )
>  endef
>
> +define filechk_dt.h
> +       (if test -n "$${DEVICE_TREE}"; then \

I think this can be:

ifneq($(DEVICE_TREE),)

> +               echo \#define DEVICE_TREE \"$(DEVICE_TREE)\"; \
> +       else \
> +               echo \#define DEVICE_TREE CONFIG_DEFAULT_DEVICE_TREE; \
> +       fi)
> +endef
> +
>  $(version_h): include/config/uboot.release FORCE
>         $(call filechk,version.h)
>
>  $(timestamp_h): $(srctree)/Makefile FORCE
>         $(call filechk,timestamp.h)
>
> +$(dt_h): $(srctree)/Makefile FORCE
> +       $(call filechk,dt.h)
> +
>  $(defaultenv_h): $(CONFIG_DEFAULT_ENV_FILE:"%"=%) FORCE
>         $(call filechk,defaultenv.h)
>
> diff --git a/arch/arm/mach-zynq/spl.c b/arch/arm/mach-zynq/spl.c
> index 96ba90fb7a76..e89e46c1038d 100644
> --- a/arch/arm/mach-zynq/spl.c
> +++ b/arch/arm/mach-zynq/spl.c
> @@ -6,6 +6,7 @@
>  #include <debug_uart.h>
>  #include <hang.h>
>  #include <spl.h>
> +#include <generated/dt.h>
>
>  #include <asm/io.h>
>  #include <asm/spl.h>
> @@ -89,8 +90,11 @@ void spl_board_prepare_for_boot(void)
>  int board_fit_config_name_match(const char *name)
>  {
>         /* Just empty function now - can't decide what to choose */
> -       debug("%s: %s\n", __func__, name);
> +       debug("%s: Check %s, default %s\n", __func__, name, DEVICE_TREE);
>
> -       return 0;
> +       if (!strcmp(name, DEVICE_TREE))
> +               return 0;
> +
> +       return -1;
>  }
>  #endif
> --
> 2.25.0
>

Regards,
Simon