[U-Boot] [PATCH v2 02/13] efi.h: Do not use config options

[Alexander Graf]

On 13.06.18 03:29, Simon Glass wrote:
> Hi Bin, Alex,
> 
> On 12 June 2018 at 09:36, Bin Meng <bmeng.cn at gmail.com> wrote:
>> From: Alexander Graf <agraf at suse.de>
>>
>> Currently efi.h determines a few bits of its environment according to
>> config options. This falls apart with the efi stub support which may
>> result in efi.h getting pulled into the stub as well as real U-Boot
>> code. In that case, one may be 32bit while the other one is 64bit.
>>
>> This patch changes the conditionals to use compiler provided defines
>> instead. That way we always adhere to the build environment we're in
>> and the definitions adjust automatically.
>>
>> Signed-off-by: Alexander Graf <agraf at suse.de>
>> Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
>> Tested-by: Bin Meng <bmeng.cn at gmail.com>
>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>> ---
>>
>> Changes in v2: None
>>
>>  include/efi.h    | 17 ++++-------------
>>  lib/efi/Makefile |  4 ++--
>>  2 files changed, 6 insertions(+), 15 deletions(-)
>>
>> diff --git a/include/efi.h b/include/efi.h
>> index 98bddba..5e1e8ac 100644
>> --- a/include/efi.h
>> +++ b/include/efi.h
>> @@ -19,12 +19,12 @@
>>  #include <linux/string.h>
>>  #include <linux/types.h>
>>
>> -#if CONFIG_EFI_STUB_64BIT || (!defined(CONFIG_EFI_STUB) && defined(__x86_64__))
>> -/* EFI uses the Microsoft ABI which is not the default for GCC */
>> +/* EFI on x86_64 uses the Microsoft ABI which is not the default for GCC */
>> +#ifdef __x86_64__
>>  #define EFIAPI __attribute__((ms_abi))
>>  #else
>>  #define EFIAPI asmlinkage
>> -#endif
>> +#endif /* __x86_64__ */
> 
> I made the same comment in another patch. This is becoming too ad-hoc
> where making EFI builds work is distributed and hidden in such a way
> that no one will be able to know whether a change causes problems or
> not.
> 
> I feel that build config should be deterministic given the CONFIG
> options provided by the board. Any checks of compiler predefines
> should be done in one place (efi.h?) and bugs in that stuff should
> there all be in one place too, and easier to debug and fix.

I actually think the opposite is true. We should get rid of any #ifdef
CONFIG_ARCH checks throughout the code base that are not meant to
actually check for the "target" (sandbox for example), but instead
really only want to know the architecture the code is building against.

We can easily trust the compiler to emit correct defines for the target
architecture it's building against. That's what every other piece of C
code on earth depends on. Why be different?


Alex