[U-Boot] [PATCH v2 5/5] x86: Remove unused real mode code

[Graeme Russ]

Hi Simon,

On Fri, Feb 15, 2013 at 1:18 AM, Simon Glass <sjg at chromium.org> wrote:
> This code is pretty old and we want to support only 32-bit systems now.
> Keep the real mode-to-protected code in case we want to boot an x86 from
> power-up, but invert the polarity of the option.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> Changes in v2:
> - Keep the real mode-to-protected code
>
>  README                          |   7 +-
>  arch/x86/include/asm/realmode.h |  36 ---
>  arch/x86/lib/Makefile           |  10 +-
>  arch/x86/lib/bios.S             | 569 ----------------------------------------
>  arch/x86/lib/bios.h             |   3 -
>  arch/x86/lib/bios_pci.S         | 447 -------------------------------
>  arch/x86/lib/bios_setup.c       | 179 -------------
>  arch/x86/lib/realmode.c         |  93 -------
>  arch/x86/lib/video.c            |   6 -
>  arch/x86/lib/video_bios.c       | 196 --------------
>  arch/x86/lib/zimage.c           |  23 --
>  11 files changed, 4 insertions(+), 1565 deletions(-)
>  delete mode 100644 arch/x86/include/asm/realmode.h
>  delete mode 100644 arch/x86/lib/bios.S
>  delete mode 100644 arch/x86/lib/bios_pci.S
>  delete mode 100644 arch/x86/lib/bios_setup.c
>  delete mode 100644 arch/x86/lib/realmode.c
>  delete mode 100644 arch/x86/lib/video_bios.c
>
> diff --git a/README b/README
> index 6106e0d..7b50720 100644
> --- a/README
> +++ b/README
> @@ -3820,10 +3820,9 @@ Low Level (hardware related) configuration options:
>                 If defined, the x86 reset vector code is included. This is not
>                 needed when U-Boot is running from Coreboot.
>
> -- CONFIG_X86_NO_REAL_MODE
> -               If defined, x86 real mode code is omitted. This assumes a
> -               32-bit environment where such code is not needed. You will
> -               need to do this when U-Boot is running from Coreboot.
> +- CONFIG_X86_REAL_MODE
> +               If defined, some 86 real mode code is included. This is not
> +               needed when U-Boot is running from Coreboot.

I think this config option can be punted completely. This define is
only used to pull in the real-mode trampoline code which switches from
protected-mode to real-mode before jumping into the Linux kernel's
real-mode stub. The code for the initial real-mode to protected-mode
switch will be pulled in by CONFIG_X86_RESET_VECTOR

Regards,

Graeme