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

[Simon Glass]

Hi Graeme,

On Thu, Feb 14, 2013 at 2:36 PM, Graeme Russ <graeme.russ at gmail.com> wrote:
> 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

I suppose I am confused about what is needed here. I will drop the
flag, and arch/x86/lib/realmode_switch.S. Is that right?

Regards,
Simon

>
> Regards,
>
> Graeme