[U-Boot] [PATCH v2 11/47] x86: Tidy up global_data flags

[Bin Meng]

Hi Simon,

On Fri, Jul 31, 2015 at 11:31 PM, Simon Glass <sjg at chromium.org> wrote:
> These flags now overlap some global ones. Adjust the x86-specific flags to
> avoid this. Since this requires a change to the start.S code, add a way for
> tools to find the 32-bit cold reset entry point. Previously this was at a
> fixed offset.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---

Reviewed-by: Bin Meng <bmeng.cn at gmail.com>

But please see nits below.

>
> Changes in v2:
> - Add a marker for the cold reset entry point
> - Use the now-defined top 16-bits of the global_data flags
>
>  arch/x86/cpu/start.S               | 8 ++++++--
>  arch/x86/include/asm/global_data.h | 8 ++++----
>  2 files changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S
> index 7ef8b88..9b2584d 100644
> --- a/arch/x86/cpu/start.S
> +++ b/arch/x86/cpu/start.S
> @@ -41,14 +41,18 @@ _x86boot_start:
>         wbinvd
>
>         /* Tell 32-bit code it is being entered from an in-RAM copy */
> -       movw    $GD_FLG_WARM_BOOT, %bx
> +       movl    $GD_FLG_WARM_BOOT, %ebx
>         jmp     1f
> +
> +       /* Add a way for tools to discover the _start entry point */
> +       .align  4
> +       .long   0x12345678
>  _start:
>         /*
>          * This is the 32-bit cold-reset entry point, coming from start16.
>          * Set %bx to 0 to indicate this.

Nits: the comment is not correct. (%bx -> %ebx, 0 -> GD_FLG_COLD_BOOT)

>          */
> -       movw    $GD_FLG_COLD_BOOT, %bx
> +       movl    $GD_FLG_COLD_BOOT, %ebx
>  1:
>         /* Save BIST */
>         movl    %eax, %ebp
> diff --git a/arch/x86/include/asm/global_data.h b/arch/x86/include/asm/global_data.h
> index 4d9eac6..3db9a4c 100644
> --- a/arch/x86/include/asm/global_data.h
> +++ b/arch/x86/include/asm/global_data.h
> @@ -87,14 +87,14 @@ static inline __attribute__((no_instrument_function)) gd_t *get_fs_gd_ptr(void)
>
>  #define gd     get_fs_gd_ptr()
>
> +#define DECLARE_GLOBAL_DATA_PTR
> +
>  #endif
>
>  /*
>   * Our private Global Data Flags
>   */
> -#define GD_FLG_COLD_BOOT       0x00100 /* Cold Boot */
> -#define GD_FLG_WARM_BOOT       0x00200 /* Warm Boot */
> -
> -#define DECLARE_GLOBAL_DATA_PTR
> +#define GD_FLG_COLD_BOOT       0x10000 /* Cold Boot */
> +#define GD_FLG_WARM_BOOT       0x20000 /* Warm Boot */
>
>  #endif /* __ASM_GBL_DATA_H */
> --

Regards,
Bin