[U-Boot] [RFC] board_f: generalize code for case of no relocation

[Simon Glass]

Hi Aexey,

On 15 December 2015 at 03:06, Alexey Brodkin
<Alexey.Brodkin at synopsys.com> wrote:
> Current implementation of disabled relocation only works for EFI.
>
> In case of GD_FLG_SKIP_RELOC jump_to_copy() will return instead of
> jumping further in board_init_r() etc. And jump_to_copy() being the last
> call in init_sequence_f when returning simply triggers hang() in
> board_init_f(). Well for everything except ARM, SANDBOX and EFI_APP.
>
> Not sure why ARM and SANBOX are here - I would assume it's all on
> purpose but as for EFI_APP this is an essential need for getting out of
> board_init_f() and jumping in board_init_r() immediately afterwards, see
> efi_main().
>
> But what if in case of no relocation we jump in board_init_r() right
> from jump_to_copy()? In that case we remove one ifdef from
> board_init_f() and leave a chance to seamlessly re-use disabled
> relocation for other (non-EFI) cases.
>
> Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
> ---
>
> Note I didn't test it for EFI because I don't know how to do that in
> simulation, please let me know if there's a simple way to do it.
>
> But I did test it for ARC boards (with additional patches) that enable
> disabled relocation - these patches to follow once something similar to
> my proposal here is implemented.
>
>  common/board_f.c  | 11 ++++++++---
>  lib/efi/efi_app.c |  2 +-
>  2 files changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/common/board_f.c b/common/board_f.c
> index eac7c5e..2d60ed9 100644
> --- a/common/board_f.c
> +++ b/common/board_f.c
> @@ -720,8 +720,14 @@ static int setup_reloc(void)
>
>  static int jump_to_copy(void)
>  {
> +       /*
> +        * In case of no relocation nothing to do between "running from flash"
> +        * (init_f) and "running from ram" (init_r), so just jumping in
> +        * board_init_r().
> +        */
>         if (gd->flags & GD_FLG_SKIP_RELOC)
> -               return 0;
> +               board_init_r((gd_t *)gd, gd->relocaddr);
> +
>         /*
>          * x86 is special, but in a nice way. It uses a trampoline which
>          * enables the dcache if possible.
> @@ -1017,8 +1023,7 @@ void board_init_f(ulong boot_flags)
>         if (initcall_run_list(init_sequence_f))
>                 hang();
>
> -#if !defined(CONFIG_ARM) && !defined(CONFIG_SANDBOX) && \
> -               !defined(CONFIG_EFI_APP)
> +#if !defined(CONFIG_ARM) && !defined(CONFIG_SANDBOX)
>         /* NOTREACHED - jump_to_copy() does not return */
>         hang();

Actually the hope is that all boards will work this way soon, so I'd
rather not remove one. I'd like to see board_init_f() return normally,
and then board_init_r() be called by the caller. In the end,
jump_to_copy() will be removed.

So can you adjust your patch to just return from jump_to_copy() and
skip this hang()? Then (I hope) on ARM it will also do the right
thing...I can help test on x86 also.

It's Christmas where I am so I may not be around much for the next few weeks.

>  #endif
> diff --git a/lib/efi/efi_app.c b/lib/efi/efi_app.c
> index 452ab5d..5e41b7f 100644
> --- a/lib/efi/efi_app.c
> +++ b/lib/efi/efi_app.c
> @@ -123,7 +123,7 @@ efi_status_t efi_main(efi_handle_t image, struct efi_system_table *sys_table)
>         printf("starting\n");
>
>         board_init_f(GD_FLG_SKIP_RELOC);
> -       board_init_r(NULL, 0);
> +       /* board_init_r() is called in the end of board_init_f() */
>         free_memory(priv);
>
>         return EFI_SUCCESS;
> --
> 2.4.3
>

Regards,
Simon