[U-Boot] [PATCH 1/6] fdtdec: allow board to provide fdt for CONFIG_OF_SEPARATE

[Simon Glass]

Hi Rob,

On 3 August 2017 at 10:48, Rob Clark <robdclark at gmail.com> wrote:
> Similar to CONFIG_OF_BOARD, but in this case the fdt is still built by
> u-boot build.  This allows the board to patch the fdt, etc.
>
> In the specific case of dragonboard 410c, we pass the u-boot generated
> fdt to the previous stage of bootloader (by embedding it in the
> u-boot.img that is loaded by lk/aboot), which patches the fdt and passes
> it back to u-boot.

Why do you need to create a weak function for this? Isn't there
already a CONFIG_OF_BOARD to enable this feature?

>
> Signed-off-by: Rob Clark <robdclark at gmail.com>
> ---
>  include/fdtdec.h |  3 ++-
>  lib/fdtdec.c     | 45 ++++++++++++++++++++++++++-------------------
>  2 files changed, 28 insertions(+), 20 deletions(-)
>
> diff --git a/include/fdtdec.h b/include/fdtdec.h
> index 4a0947c626..b9acec735a 100644
> --- a/include/fdtdec.h
> +++ b/include/fdtdec.h
> @@ -986,7 +986,8 @@ int fdtdec_setup(void);
>
>  /**
>   * Board-specific FDT initialization. Returns the address to a device tree blob.
> - * Called when CONFIG_OF_BOARD is defined.
> + * Called when CONFIG_OF_BOARD is defined, or if CONFIG_OF_SEPARATE is defined
> + * and the board implements it.
>   */
>  void *board_fdt_blob_setup(void);
>
> diff --git a/lib/fdtdec.c b/lib/fdtdec.c
> index d2dbd0f122..07c458673c 100644
> --- a/lib/fdtdec.c
> +++ b/lib/fdtdec.c
> @@ -1203,34 +1203,41 @@ int fdtdec_setup_memory_banksize(void)
>  }
>  #endif
>
> -int fdtdec_setup(void)
> +#ifdef CONFIG_OF_SEPARATE
> +/*
> + * For CONFIG_OF_SEPARATE, the board may optionally implement this to
> + * provide and/or fixup the fdt.
> + */
> +__weak void *board_fdt_blob_setup(void)
>  {
> -#if CONFIG_IS_ENABLED(OF_CONTROL)
> -# ifdef CONFIG_OF_EMBED
> -       /* Get a pointer to the FDT */
> -       gd->fdt_blob = __dtb_dt_begin;
> -# elif defined CONFIG_OF_SEPARATE
> -#  ifdef CONFIG_SPL_BUILD
> +       void *fdt_blob = NULL;
> +#ifdef CONFIG_SPL_BUILD
>         /* FDT is at end of BSS unless it is in a different memory region */
>         if (IS_ENABLED(CONFIG_SPL_SEPARATE_BSS))
> -               gd->fdt_blob = (ulong *)&_image_binary_end;
> +               fdt_blob = (ulong *)&_image_binary_end;
>         else
> -               gd->fdt_blob = (ulong *)&__bss_end;
> +               fdt_blob = (ulong *)&__bss_end;
>
> -#  elif defined CONFIG_FIT_EMBED
> -       gd->fdt_blob = locate_dtb_in_fit(&_end);
> +#elif defined CONFIG_FIT_EMBED
> +       fdt_blob = locate_dtb_in_fit(&_end);
>
> -       if (gd->fdt_blob == NULL || gd->fdt_blob <= ((void *)&_end)) {
> +       if (fdt_blob == NULL || fdt_blob <= ((void *)&_end))
>                 puts("Failed to find proper dtb in embedded FIT Image\n");
> -               return -1;
> -       }
> -
> -#  else
> +#else
>         /* FDT is at end of image */
> -       gd->fdt_blob = (ulong *)&_end;
> +       fdt_blob = (ulong *)&_end;
>  #  endif
> -# elif defined(CONFIG_OF_BOARD)
> -       /* Allow the board to override the fdt address. */
> +       return fdt_blob;
> +}
> +#endif
> +
> +int fdtdec_setup(void)
> +{
> +#if CONFIG_IS_ENABLED(OF_CONTROL)
> +# ifdef CONFIG_OF_EMBED
> +       /* Get a pointer to the FDT */
> +       gd->fdt_blob = __dtb_dt_begin;
> +# elif defined(CONFIG_OF_SEPARATE) || defined(CONFIG_OF_BOARD)
>         gd->fdt_blob = board_fdt_blob_setup();
>  # elif defined(CONFIG_OF_HOSTFILE)
>         if (sandbox_read_fdt_from_file()) {
> --
> 2.13.0
>

Regards,
Simon