[llvm-dev] How to objcopy via LLVM toolchain for armv7e-m ELF32LE?

[James Henderson via llvm-dev]

Hi,

At the moment, we've only added support for 64-bit Little Endian ELF to
llvm-objcopy, but I'm pretty sure most of the code should be able to handle
32-bit ELF as well, with a patch such as the one you've attached. Jake
Ehrlich (CC'ed), who is the main developer on llvm-objcopy should be able
to give you a more complete answer.

Regards,

James

On 13 November 2017 at 07:00, Leslie Zhai via llvm-dev <
llvm-dev at lists.llvm.org> wrote:

> Testcase: https://github.com/xiangzhai/mini-arm-os/tree/llvm-toolchain
> /00-HelloWorld
>
> $ make
>  CC hello.c
>  CC startup.c
>  LD hello.elf
>  READ -> hello.rd
>  LIST -> hello.lst
>  COPY -> hello.bin
>    text    data     bss     dec     hex filename
>     190      14       0     204      cc hello.elf
>
> $ make qemu
> /data/project/qemu_stm32/arm-softmmu/qemu-system-arm -M stm32-p103
> -nographic -kernel hello.bin
>
> ...
> LED Off
> Hello World!
>
>
> 在 2017年11月13日 14:14, Leslie Zhai 写道:
>
>> Is it able to just workaround add ELF32LE?
>>
>>
>> diff --git a/tools/llvm-objcopy/llvm-objcopy.cpp
>> b/tools/llvm-objcopy/llvm-objcopy.cpp
>> index 54186f6..3234c65 100644
>> --- a/tools/llvm-objcopy/llvm-objcopy.cpp
>> +++ b/tools/llvm-objcopy/llvm-objcopy.cpp
>> @@ -138,18 +138,19 @@ void SplitDWOToFile(const ELFObjectFile<ELFT>
>> &ObjFile, StringRef File) {
>>    WriteObjectFile(DWOFile, File);
>>  }
>>
>> -void CopyBinary(const ELFObjectFile<ELF64LE> &ObjFile) {
>> -  std::unique_ptr<Object<ELF64LE>> Obj;
>> +template <class ELFT = ELF64LE>
>> +void CopyBinary(const ELFObjectFile<ELFT> &ObjFile) {
>> +  std::unique_ptr<Object<ELFT>> Obj;
>>
>>    if (!OutputFormat.empty() && OutputFormat != "binary")
>>      error("invalid output format '" + OutputFormat + "'");
>>    if (!OutputFormat.empty() && OutputFormat == "binary")
>> -    Obj = llvm::make_unique<BinaryObject<ELF64LE>>(ObjFile);
>> +    Obj = llvm::make_unique<BinaryObject<ELFT>>(ObjFile);
>>    else
>> -    Obj = llvm::make_unique<ELFObject<ELF64LE>>(ObjFile);
>> +    Obj = llvm::make_unique<ELFObject<ELFT>>(ObjFile);
>>
>>    if (!SplitDWO.empty())
>> -    SplitDWOToFile<ELF64LE>(ObjFile, SplitDWO.getValue());
>> +    SplitDWOToFile<ELFT>(ObjFile, SplitDWO.getValue());
>>
>>    SectionPred RemovePred = [](const SectionBase &) { return false; };
>>
>> @@ -200,6 +201,9 @@ int main(int argc, char **argv) {
>>    if (ELFObjectFile<ELF64LE> *o = dyn_cast<ELFObjectFile<ELF64LE>>(&Binary))
>> {
>>      CopyBinary(*o);
>>      return 0;
>> +  } else if (ELFObjectFile<ELF32LE> *o = dyn_cast<ELFObjectFile<ELF32LE>>(&Binary))
>> {
>> +    CopyBinary(*o);
>> +    return 0;
>>    }
>>    reportError(InputFilename, object_error::invalid_file_type);
>>  }
>>
>>
>>
>> 在 2017年11月13日 11:32, Leslie Zhai 写道:
>>
>>> Hi LLVM developers,
>>>
>>> As PR35281 mentioned:
>>>
>>> $ llvm-objcopy -O binary llvm-cortex-m7.elf llvm-cortex-m7.bin
>>> llvm-objcopy: 'llvm-cortex-m7.elf': The file was not recognized as a
>>> valid object file.
>>>
>>>
>>> if (ELFObjectFile<ELF64LE> *o = dyn_cast<ELFObjectFile<ELF64LE>>(&Binary))
>>> https://github.com/llvm-mirror/llvm/blob/master/tools/llvm-
>>> objcopy/llvm-objcopy.cpp#L200
>>>
>>>
>>> Please give me some hints about objcopy armv7e-m ELF32LE via LLVM
>>> toolchain, thanks a lot!
>>>
>>>
>>
> --
> Regards,
> Leslie Zhai - https://reviews.llvm.org/p/xiangzhai/
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
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