PATCH: Fix EFI support

[H.J. Lu]

On Wed, Apr 15, 2009 at 2:14 PM, H.J. Lu <hongjiu.lu@intel.com> wrote:
> On Wed, Apr 15, 2009 at 02:05:25PM -0700, H.J. Lu wrote:
>> This patch:
>>
>> http://sourceware.org/ml/binutils/2008-02/msg00051.html
>>
>> breaks EFI. I got
>>
>> [hjl@gnu-6 HelloWorldUefiGcc4.4]$ file HelloWorld.dll
>> HelloWorld.dll: PE32+ executable (EFI boot service driver)
>> [hjl@gnu-6 HelloWorldUefiGcc4.4]$ objdump -p HelloWorld.dll
>> objdump: HelloWorld.dll: File format not recognized
>> [hjl@gnu-6 HelloWorldUefiGcc4.4]$
>>
>> The problem is we have 3 EFI targets for each arch. When we scan
>> all targets on EFI input, we always reach
>>
>> if (efi)
>> {
>>   bfd_set_error (bfd_error_wrong_format);
>>   return NULL;
>> }
>>
>> This patch fixes by checking Subsystem.  This patch also adds
>> bfd_target_efi_p so that we only needs to check one "efi-" instead of
>> 3 "efi-XXX-".  OK for trunl?
>>
>
> Here is the updated patch to support ia64 EFI. OK for trunk?
>
> Thanks.
>
>
> H.J.
> ---
> 2009-04-15  H.J. Lu  <hongjiu.lu@intel.com>
>
>        * libpei.h (bfd_target_efi_p): New.
>        (bfd_pe_executable_p): Use it.
>
>        * peicode.h (arch_type): Add arch_type_ia64.
>        (pe_arch): Support arch_type_ia64.
>        (pe_bfd_object_p): Properly check EFI and PE.
>

The more I look at, the more I don't like the current solution.
If I understand it correctly, we added 2 EFI targets for
each arch just so that we can do

# objcopy  -O efi-XXX-x86_64 HelloWorld.elf HelloWorld.efi

The only difference between 3 EFI targets is different
IMAGE_SUBSYSTEM_EFI_XXX. Why not just have one EFI
target, efi-x8_64, defaulting to IMAGE_SUBSYSTEM_EFI_APPLICATION??
We can add a switch to objcopy with

--efi=app|bsdrv|rtdrv

We can provide backward compatibility for efi-XXX-x86_64.
Any comments?

Thanks.

-- 
H.J.