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

[Leslie Zhai via llvm-dev]

Hi James,

Thanks for your kind response!

Jake has already provided the great patch 
https://reviews.llvm.org/D39977 The Flash Man :) so quick response to 
cover ARMmbed usecase for armv7e-m!

Thanks again for your great job!


在 2017年11月13日 22:27, James Henderson 写道:
> 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 <mailto:llvm-dev at lists.llvm.org>> wrote:
>
>     Testcase:
>     https://github.com/xiangzhai/mini-arm-os/tree/llvm-toolchain/00-HelloWorld
>     <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
>             <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/
>     <https://reviews.llvm.org/p/xiangzhai/>
>
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>
>

-- 
Regards,
Leslie Zhai - https://reviews.llvm.org/p/xiangzhai/