[U-Boot] [PATCH 09/33] x86: Factor out common values in the link script

[Bin Meng]

Hi Simon,

On Wed, Nov 12, 2014 at 8:17 AM, Simon Glass <sjg at chromium.org> wrote:
> Define the reset base in config.mk so that it does not need to be calculated
> twice in the link script. Also tidy up the START_16 and RESET_VEC_LOC values
> to fit with this new approach.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
>  arch/x86/cpu/config.mk  |  5 +++--
>  arch/x86/cpu/u-boot.lds | 13 +++++++++----
>  2 files changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/cpu/config.mk b/arch/x86/cpu/config.mk
> index f7b01d3..84aeaf3 100644
> --- a/arch/x86/cpu/config.mk
> +++ b/arch/x86/cpu/config.mk
> @@ -12,5 +12,6 @@ PLATFORM_CPPFLAGS += -D__I386__ -Werror
>  # DO NOT MODIFY THE FOLLOWING UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!
>  LDPPFLAGS += -DRESET_SEG_START=0xffff0000
>  LDPPFLAGS += -DRESET_SEG_SIZE=0x10000
> -LDPPFLAGS += -DRESET_VEC_LOC=0xfff0
> -LDPPFLAGS += -DSTART_16=0xf800
> +LDPPFLAGS += -DRESET_VEC_LOC=0xfffffff0
> +LDPPFLAGS += -DSTART_16=$(CONFIG_SYS_X86_START16)
> +LDPPFLAGS += -DRESET_BASE="CONFIG_SYS_TEXT_BASE + (CONFIG_SYS_MONITOR_LEN - RESET_SEG_SIZE)"
> diff --git a/arch/x86/cpu/u-boot.lds b/arch/x86/cpu/u-boot.lds
> index 95ab7dd..2a23e18 100644
> --- a/arch/x86/cpu/u-boot.lds
> +++ b/arch/x86/cpu/u-boot.lds
> @@ -71,10 +71,15 @@ SECTIONS
>          * The following expressions place the 16-bit Real-Mode code and
>          * Reset Vector at the end of the Flash ROM
>          */
> -       . = START_16;
> -       .start16 : AT (CONFIG_SYS_TEXT_BASE + (CONFIG_SYS_MONITOR_LEN - RESET_SEG_SIZE + START_16)) { KEEP(*(.start16)); }
> +       . = START_16 - RESET_SEG_START;
> +       .start16 : AT (START_16 - RESET_SEG_START) {
> +               KEEP(*(.start16));
> +       }

What's the reason of changing AT of .start16 section?

> -       . = RESET_VEC_LOC;
> -       .resetvec : AT (CONFIG_SYS_TEXT_BASE + (CONFIG_SYS_MONITOR_LEN - RESET_SEG_SIZE + RESET_VEC_LOC)) { KEEP(*(.resetvec)); }
> +       . = RESET_VEC_LOC - RESET_SEG_START;
> +       .resetvec : AT (RESET_VEC_LOC - RESET_SEG_START) {
> +               KEEP(*(.resetvec));
> +       }

Ditto.

>  #endif
> +
>  }
> --

Regards,
Bin