[PATCH v4 01/39] arm: init: export prev_bl_fdt_addr

[Sumit Garg]

On Fri, 16 Feb 2024 at 02:22, Caleb Connolly <caleb.connolly at linaro.org> wrote:
>
> When booting U-Boot on board with a locked down first-stage bootloader,
> we emulate the Linux boot header. By passing the U-Boot FDT through this
> first-stage bootloader and retrieving it afterwards we can pre-populate
> the memory nodes and other info like the KASLR address.
>
> Add a function to export the FDT addr so that boards can use it over the
> built-in FDT.
>
> Don't check is_addr_accessible() here because we might not yet have a
> valid mem_map if it's going to be populated from the FDT, let the board
> do their own validation instead.
>
> Reviewed-by: Tom Rini <trini at konsulko.com>
> Signed-off-by: Caleb Connolly <caleb.connolly at linaro.org>
> ---
>  arch/arm/lib/save_prev_bl_data.c |  5 +++++
>  include/init.h                   | 11 +++++++++++
>  2 files changed, 16 insertions(+)

Reviewed-by: Sumit Garg <sumit.garg at linaro.org>

-Sumit

>
> diff --git a/arch/arm/lib/save_prev_bl_data.c b/arch/arm/lib/save_prev_bl_data.c
> index f7b23faf0d66..b286bac9bf00 100644
> --- a/arch/arm/lib/save_prev_bl_data.c
> +++ b/arch/arm/lib/save_prev_bl_data.c
> @@ -45,6 +45,11 @@ bool is_addr_accessible(phys_addr_t addr)
>         return false;
>  }
>
> +phys_addr_t get_prev_bl_fdt_addr(void)
> +{
> +       return reg0;
> +}
> +
>  int save_prev_bl_data(void)
>  {
>         struct fdt_header *fdt_blob;
> diff --git a/include/init.h b/include/init.h
> index 9a1951d10a01..630d86729c4e 100644
> --- a/include/init.h
> +++ b/include/init.h
> @@ -168,6 +168,17 @@ defined(CONFIG_SAVE_PREV_BL_FDT_ADDR)
>   * Return: 0 if ok; -ENODATA on error
>   */
>  int save_prev_bl_data(void);
> +
> +/**
> + * get_prev_bl_fdt_addr - When u-boot is chainloaded, get the address
> + * of the FDT passed by the previous bootloader.
> + *
> + * Return: the address of the FDT passed by the previous bootloader
> + * or 0 if not found.
> + */
> +phys_addr_t get_prev_bl_fdt_addr(void);
> +#else
> +#define get_prev_bl_fdt_addr() 0LLU
>  #endif
>
>  /**
>
> --
> 2.43.1
>