[U-Boot] [PATCH v2 4/8] x86: Tidy up selection of building the EFI stub

[Alexander Graf]

> Am 29.09.2016 um 05:37 schrieb Bin Meng <bmeng.cn at gmail.com>:
> 
> Hi Simon,
> 
>> On Wed, Sep 28, 2016 at 10:43 PM, Simon Glass <sjg at chromium.org> wrote:
>> Hi Bin,
>> 
>>> On 27 September 2016 at 19:23, Bin Meng <bmeng.cn at gmail.com> wrote:
>>> Hi Simon,
>>> 
>>>> On Wed, Sep 28, 2016 at 1:55 AM, Simon Glass <sjg at chromium.org> wrote:
>>>> Hi Bin,
>>>> 
>>>>> On 26 September 2016 at 20:44, Bin Meng <bmeng.cn at gmail.com> wrote:
>>>>> Hi Simon,
>>>>> 
>>>>>> On Tue, Sep 27, 2016 at 8:35 AM, Simon Glass <sjg at chromium.org> wrote:
>>>>>> Hi Bin,
>>>>>> 
>>>>>>> On 26 September 2016 at 02:50, Bin Meng <bmeng.cn at gmail.com> wrote:
>>>>>>> Hi Simon,
>>>>>>> 
>>>>>>>> On Mon, Sep 26, 2016 at 5:27 AM, Simon Glass <sjg at chromium.org> wrote:
>>>>>>>> At present we use a CONFIG option in efi.h to determine whether we are
>>>>>>>> building the EFI stub or not. This means that the same header cannot be
>>>>>>>> used for EFI_LOADER support. The CONFIG option will be enabled for the
>>>>>>>> whole build, even when not building the stub.
>>>>>>>> 
>>>>>>>> Use a different define instead, set up just for the files that make up the
>>>>>>>> stub.
>>>>>>>> 
>>>>>>>> Signed-off-by: Simon Glass <sjg at chromium.org>
>>>>>>>> ---
>>>>>>>> 
>>>>>>>> Changes in v2:
>>>>>>>> - Add new patch to tidy up selection of building the EFI stub
>>>>>>>> 
>>>>>>>> include/efi.h    | 7 +++++--
>>>>>>>> lib/efi/Makefile | 4 ++--
>>>>>>>> 2 files changed, 7 insertions(+), 4 deletions(-)
>>>>>>>> 
>>>>>>>> diff --git a/include/efi.h b/include/efi.h
>>>>>>>> index d07187c..3d58780 100644
>>>>>>>> --- a/include/efi.h
>>>>>>>> +++ b/include/efi.h
>>>>>>>> @@ -30,8 +30,11 @@ struct efi_device_path;
>>>>>>>> 
>>>>>>>> #define EFI_BITS_PER_LONG      BITS_PER_LONG
>>>>>>>> 
>>>>>>>> -/* With 64-bit EFI stub, EFI_BITS_PER_LONG has to be 64 */
>>>>>>>> -#ifdef CONFIG_EFI_STUB_64BIT
>>>>>>>> +/*
>>>>>>>> + * With 64-bit EFI stub, EFI_BITS_PER_LONG has to be 64. EFI_STUB is set
>>>>>>>> + * in lib/efi/Makefile, when building the stub.
>>>>>>>> + */
>>>>>>>> +#if defined(CONFIG_EFI_STUB_64BIT) && defined(EFI_STUB)
>>>>>>> 
>>>>>>> I don't understand why this is needed?
>>>>>> 
>>>>>> If building the 64-bit EFI stub, we need to use 64-bit ints for the
>>>>>> stub, but 32-bits for the rest of U-Boot. So this header gets used
>>>>>> both ways.
>>>>>> 
>>>>> 
>>>>> For 32-bit EFI stub or U-Boot itself, EFI_BITS_PER_LONG is defined as
>>>>> BITS_PER_LONG which is 32.
>>>> 
>>>> Yes that's right. But in the case of the stub, it can be different
>>>> from U-Boot itself. This case takes care of that.
>>>> 
>>> 
>>> Sorry but I still don't get it. What's broken without this change?
>> 
>> When building U-Boot with CONFIG_EFI_STUB_64BIT enabled, at present
>> EFI_BITS_PER_LONG will be 64.
>> 
>> This is fine for building the stub.
>> 
> 
> Yes
> 
>> But for building U-Boot, we still want it to be 32.
>> 
> 
> Yes
> 
>> At present the code overrides EFI_BITS_PER_LONG, setting it to 64 if
>> CONFIG_EFI_STUB_64BIT is enabled.
>> 
>> This means that EFI_LOADER support does not build properly, since it
>> uses 64 instead of 32.
>> 
> 
> So you want CONFIG_EFI_STUB_64BIT and CONFIG_EFI_LOADER both be
> defined? I don't think it is a valid configuration.

Why not?

Alex