[PATCH 2/2] arm: crt0_64: support skip u-boot relocation

[Simon Glass]

Hi Peng,

On Wed, 13 Oct 2021 at 03:18, Peng Fan (OSS) <peng.fan at oss.nxp.com> wrote:
>
> From: Peng Fan <peng.fan at nxp.com>
>
> U-Boot binary is quite large with more options enabled, it not hurt
> on real silicon with high performance. But on simulation platform,
> it is quite slow to relocate the U-Boot binary to new address,
> so let's support skipping relocation.
>
> Users could use 'gd->flags |= GD_FLG_SKIP_RELOC;' in board_early_init_f
> or other place that early than relocate_code.
>
> Signed-off-by: Peng Fan <peng.fan at nxp.com>
> ---
>  arch/arm/lib/crt0_64.S | 6 ++++++
>  1 file changed, 6 insertions(+)

Reviewed-by: Simon Glass <sjg at chromium.org>

>
> diff --git a/arch/arm/lib/crt0_64.S b/arch/arm/lib/crt0_64.S
> index 680e674fa3..d57ca84ee4 100644
> --- a/arch/arm/lib/crt0_64.S
> +++ b/arch/arm/lib/crt0_64.S
> @@ -12,6 +12,7 @@
>  #include <config.h>
>  #include <asm-offsets.h>
>  #include <asm/macro.h>
> +#include <asm-generic/global_data.h>
>  #include <linux/linkage.h>
>
>  /*
> @@ -95,6 +96,7 @@ ENTRY(_main)
>         bl      board_init_f
>
>  #if !defined(CONFIG_SPL_BUILD)
> +       ldr     x1, [x18, #GD_FLAGS]
>  /*
>   * Set up intermediate environment (new sp and gd) and call
>   * relocate_code(addr_moni). Trick here is that we'll return
> @@ -122,6 +124,10 @@ ENTRY(_main)
>         ldr     x9, [x18, #GD_RELOC_OFF]        /* x9 <- gd->reloc_off */
>         add     lr, lr, x9      /* new return address after relocation */
>         ldr     x0, [x18, #GD_RELOCADDR]        /* x0 <- gd->relocaddr */
> +
> +       tst     x1, #GD_FLG_SKIP_RELOC
> +       bne     relocation_return

Could we document this feature somewhere, or add a comment here as to
why this is useful?

> +
>         b       relocate_code
>
>  relocation_return:
> --
> 2.30.0
>

Regards,
SImon