[U-Boot] [PATCH 02/17] x86: Speed up copy-to-RAM and clear BSS operations

Simon Glass sjg at chromium.org
Wed Jan 4 06:21:42 CET 2012


Hi Graeme,

On Sun, Jan 1, 2012 at 8:09 PM, Graeme Russ <graeme.russ at gmail.com> wrote:
> The implementations of memcpy and memset are now the optimised versions
> from glibc, so use them instead of simple copy loops
>
> Signed-off-by: Graeme Russ <graeme.russ at gmail.com>
> ---
>  arch/x86/lib/board.c |   17 +++++------------
>  1 files changed, 5 insertions(+), 12 deletions(-)
>
> diff --git a/arch/x86/lib/board.c b/arch/x86/lib/board.c
> index d742fec..ba6b59f 100644
> --- a/arch/x86/lib/board.c
> +++ b/arch/x86/lib/board.c
> @@ -188,26 +188,19 @@ static int calculate_relocation_address(void)
>
>  static int copy_uboot_to_ram(void)
>  {
> -       ulong *dst_addr = (ulong *)gd->relocaddr;
> -       ulong *src_addr = (ulong *)&__text_start;
> -       ulong *end_addr = (ulong *)&__data_end;
> +       size_t len = (size_t)(&__data_end) - (size_t)(&__text_start);

Extra brackets here. Also is the type of these not char[] already? Same Q below.

>
> -       while (src_addr < end_addr)
> -               *dst_addr++ = *src_addr++;
> +       memcpy((void *)gd->relocaddr, (void *)&__text_start, len);
>
>        return 0;
>  }
>
>  static int clear_bss(void)
>  {
> -       void *bss_start = &__bss_start;
> -       void *bss_end = &__bss_end;
> +       ulong dst_addr = (ulong)(&__bss_start) + gd->reloc_off;
> +       size_t len = (size_t)(&__bss_end) - (size_t)(&__bss_start);
>
> -       ulong *dst_addr = (ulong *)(bss_start + gd->reloc_off);
> -       ulong *end_addr = (ulong *)(bss_end + gd->reloc_off);
> -
> -       while (dst_addr < end_addr)
> -               *dst_addr++ = 0x00000000;
> +       memset((void *)dst_addr, 0x00, len);
>
>        return 0;
>  }
> --
> 1.7.5.2.317.g391b14
>
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