Ard,
I would try to explain here,

1.Till now we have been compiling CPP programs in UDK with VS2005/VS2008 as toolchain and it worked well.

2.Now,we have a requirement to support AARCH64 architecture with ARMGCC as the toolchain.But when we tried to compile our CPP code/Sample HelloWorld application(HelloWorld.c is renamed to HelloWorld.cpp)  with ARMGCC as toolchain,we were seeing relocation errors such as 0x105.

3.As advised by you,we tried compiling a sample HelloWorld CPP program under EDK2 and still we are seeing the same relocation errors.

Questions:

1.If EDK2 doesn't support CPP code,what should we do to resolve the relocation errors we are observing?

Please correct me,if I have missed something.

Thanks.
From: Ard Biesheuvel
Sent: ‎01-‎02-‎2016 11:59
To: Ravikanth MVR
Cc: Leif Lindholm; Daniel Samuelraj; Jianning Wang; Linaro UEFI Mailman List; Sadananda Murthy; Unnikrishnan P S
Subject: Re: [Linaro-uefi] Compiling CPP files ARM64

On 31 January 2016 at 20:16, Ravikanth MVR <ravikanth.mvr@avagotech.com> wrote:
> +Unni.
>
> Ard,
> I have done a native compilation with EDK2 and I am facing same issues as I
> did before.Below is the snapshot of the errors I received.
>

I have explained twice already why C++ under EDK2 is not going to
work. What exactly were you expecting?
--
Ard.


> "GenFw" -e UEFI_APPLICATION -o
> /home/edk2/MyWorkSpace/Build/MdeModule/RELEASE_ARMGCC/AARCH64/MdeModulePkg/Application/HelloWorld/HelloWorld/DEBUG/HelloWorld.efi
> /home/edk2/MyWorkSpace/Build/MdeModule/RELEASE_ARMGCC/AARCH64/MdeModulePkg/Application/HelloWorld/HelloWorld/DEBUG/HelloWorld.dll
> GenFw: ERROR 3000: Invalid
>   WriteSections64():
> /home/edk2/MyWorkSpace/Build/MdeModule/RELEASE_ARMGCC/AARCH64/MdeModulePkg/Application/HelloWorld/HelloWorld/DEBUG/HelloWorld.dll
> unsupported ELF EM_AARCH64 relocation 0x105.
> GenFw: ERROR 3000: Invalid
> make: ***
> [/home/edk2/MyWorkSpace/Build/MdeModule/RELEASE_ARMGCC/AARCH64/MdeModulePkg/Application/HelloWorld/HelloWorld/DEBUG/HelloWorld.efi]
> Error 2
>   WriteRelocations64():
> /home/edk2/MyWorkSpace/Build/MdeModule/RELEASE_ARMGCC/AARCH64/MdeModulePkg/Application/HelloWorld/HelloWorld/DEBUG/HelloWorld.dll
> unsupported ELF EM_AARCH64 relocation 0x105.
>
>
> build.py...
>  : error 7000: Failed to execute command
>         make --no-print-directory all
> [/home/edk2/MyWorkSpace/Build/MdeModule/RELEASE_ARMGCC/AARCH64/MdeModulePkg/Application/HelloWorld/HelloWorld]
>
> - Failed -
> Build end time: 19:12:41, Jan.31 2016
> Build total time: 00:00:15
>
> Thanks
> Ravi
>
> On Wed, Jan 27, 2016 at 2:31 PM, Ard Biesheuvel <ard.biesheuvel@linaro.org>
> wrote:
>>
>> On 27 January 2016 at 09:51, Ravikanth MVR <ravikanth.mvr@avagotech.com>
>> wrote:
>> > Ard,
>> > I was trying to compile and generate helloworld application via
>> > EDK2.Under
>> > the "MyWorkSpace\BaseTools\Bin" directory I did not find "Win32"
>> > directory
>> > which has GenFw utility.But the UDK package has Win32 directory.
>> >
>> > Could you let me know on how to build and EDK2 package in Windows or
>> > else Am
>> > I missing something here?
>> >
>>
>> I haven't used Windows for software development work in 15 years, so I
>> am really not the person you should be asking this.
>>
>> --
>> Ard.
>>
>> > On Thu, Jan 14, 2016 at 3:03 PM, Ravikanth MVR
>> > <ravikanth.mvr@avagotech.com>
>> > wrote:
>> >>
>> >> In UDK.I will try out on EDK2 and let you know the results.
>> >>
>> >> Thanks.
>> >>
>> >> On Thu, Jan 14, 2016 at 3:02 PM, Ard Biesheuvel
>> >> <ard.biesheuvel@linaro.org> wrote:
>> >>>
>> >>> On 14 January 2016 at 10:28, Ravikanth MVR
>> >>> <ravikanth.mvr@avagotech.com>
>> >>> wrote:
>> >>> > Ard,
>> >>> >
>> >>> > OK.But when a simple HelloWorld program,which is part of EDK2 sample
>> >>> > programs and which is written in c,is renamed to .CPP,we get these
>> >>> > relocation issues in-spite of not using any C++ runtime API's.
>> >>> >
>> >>>
>> >>> In UDK or EDK2?
>> >>>
>> >>> > On Thu, Jan 14, 2016 at 2:39 PM, Ard Biesheuvel
>> >>> > <ard.biesheuvel@linaro.org>
>> >>> > wrote:
>> >>> >>
>> >>> >> On 14 January 2016 at 10:06, Ravikanth MVR
>> >>> >> <ravikanth.mvr@avagotech.com>
>> >>> >> wrote:
>> >>> >> > Hi Ard,
>> >>> >> >
>> >>> >> > Hope you remember we speaking about the 0x105 and 0x0 relocation
>> >>> >> > issues
>> >>> >> > which we came across while compiling a simple HelloWorld program
>> >>> >> > in
>> >>> >> > CPP.As
>> >>> >> > you said on the other thread(EDK2 mailing list)we need some
>> >>> >> > changes
>> >>> >> > to
>> >>> >> > compiler and GenFw utility of UDK,can we take the required
>> >>> >> > changes
>> >>> >> > forward
>> >>> >> > and come up with a UDK with this support?
>> >>> >> >
>> >>> >> > We are stuck at this juncture with this activity and would need
>> >>> >> > your
>> >>> >> > help
>> >>> >> > badly.
>> >>> >> >
>> >>> >>
>> >>> >> Please forget about UDK, and rebase your work onto the latest EDK2
>> >>> >> master branch. There have been many changes to the way relocations
>> >>> >> are
>> >>> >> handled, which also impose requirements at link time (i.e., in
>> >>> >> terms
>> >>> >> of section alignment, and relative offset between sections both in
>> >>> >> the
>> >>> >> ELF and the PE/COFF versions of the image)
>> >>> >>
>> >>> >> However, the relocation issue was due to the fact that you were
>> >>> >> using
>> >>> >> the Linux version of the C++ runtime, which you cannot use under
>> >>> >> EDK2
>> >>> >> even if we do support those relocation types with the newer tools.
>> >>> >>
>> >>> >> Bottom line is that you need to develop your own C++ minimal
>> >>> >> runtime
>> >>> >> if you want to run C++ programs under EDK2
>> >>> >>
>> >>> >> > On Tue, Jan 5, 2016 at 4:29 PM, Ravikanth MVR
>> >>> >> > <ravikanth.mvr@avagotech.com>
>> >>> >> > wrote:
>> >>> >> >>
>> >>> >> >> +Sada.
>> >>> >> >>
>> >>> >> >> Thanks.
>> >>> >> >>
>> >>> >> >> On Wed, Dec 30, 2015 at 8:38 PM, Ard Biesheuvel
>> >>> >> >> <ard.biesheuvel@linaro.org> wrote:
>> >>> >> >>>
>> >>> >> >>> On 30 December 2015 at 16:02, Leif Lindholm
>> >>> >> >>> <leif.lindholm@linaro.org>
>> >>> >> >>> wrote:
>> >>> >> >>> > Hi Daniel,
>> >>> >> >>> >
>> >>> >> >>> > Sorry, your email got stuck in my SPAM folder for some
>> >>> >> >>> > reason.
>> >>> >> >>> >
>> >>> >> >>> > On Wed, Dec 23, 2015 at 05:25:21PM -0500, Daniel Samuelraj
>> >>> >> >>> > wrote:
>> >>> >> >>> >> We are able to compile CPP files for X64 using UDK2014 by
>> >>> >> >>> >> using
>> >>> >> >>> >> Visual
>> >>> >> >>> >> Studio.
>> >>> >> >>> >>
>> >>> >> >>> >> How do we compile the same source for AARCH64?
>> >>> >> >>>
>> >>> >> >>> Do you mean C++? That is completely unsupported, and is going
>> >>> >> >>> to
>> >>> >> >>> be
>> >>> >> >>> quite a challenge to implement. Note that you cannot rely on
>> >>> >> >>> the
>> >>> >> >>> C++
>> >>> >> >>> runtime for various reasons (including, but not limited to, the
>> >>> >> >>> fact
>> >>> >> >>> that it uses small model relocations, and is built against libc
>> >>> >> >>> on
>> >>> >> >>> Linux) I wonder how that even works on Visual Studio for X64,
>> >>> >> >>> since
>> >>> >> >>> the code you build will try to call libc functions from the VC
>> >>> >> >>> runtime
>> >>> >> >>> library.
>> >>> >> >>>
>> >>> >> >>> There has been some discussion about this recently on the list.
>> >>> >> >>> If
>> >>> >> >>> you
>> >>> >> >>> disable exceptions and RTTI, and reimplement your new and
>> >>> >> >>> delete
>> >>> >> >>> operators, you may be able to build code that does not rely on
>> >>> >> >>> advanced C++ runtime features.
>> >>> >> >>>
>> >>> >> >>> --
>> >>> >> >>> Ard.
>> >>> >> >>
>> >>> >> >>
>> >>> >> >
>> >>> >
>> >>> >
>> >>
>> >>
>> >
>
>