<html>
    <head>
      <base href="https://bugs.llvm.org/">
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Missing support for MIPS --binary-architecture and --output-target values"
   href="https://bugs.llvm.org/show_bug.cgi?id=41462">41462</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Missing support for MIPS --binary-architecture and --output-target values
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>tools
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>trunk
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>enhancement
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>llvm-objcopy/strip
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>arichardson.kde@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>alexander.v.shaposhnikov@gmail.com, jake.h.ehrlich@gmail.com, jh7370.2008@my.bristol.ac.uk, llvm-bugs@lists.llvm.org, rupprecht@google.com
          </td>
        </tr></table>
      <p>
        <div>
        <pre>I am trying to switch CheriBSD (fork of FreeBSD with support for the MIPS-based
CHERI CPU) to use llvm binutils instead of elftoolchain.

The build currently fails while embedding a rootfs in the kernel with the
following command:

/Users/alex/cheri/output/sdk/bin/objcopy --input-target binary --output-target
elf64-tradbigmips --binary-architecture mips
/Users/alex/cheri/output/minimal-cheri128-disk.img
embedfs_minimal-cheri128-disk.o


I guess objcopy should support the same flags for --output-target as lld. There
is a list in lld/ELF/ScriptParser.cpp in parseBfdName(StringRef S).

The second flag: --binary-architecture is currently ignored by elftoolchain
objcopy.
I'm not sure what we should do here, to me "mips" would indicate 32-bit big
endian MIPS. If I parse binutils/bfd/archures.c correctly there also doesn't
seem to be a 64-bit version of mips for --binary-architecture.
I guess we can just remove the binary-architecture from the build system but it
would be nice to be GNU and elftoolchain compatible.


llvm-objcopy seems to override --output-target if --binary-architecture is
specified which is not what we want. However, if I run this command line with
GNU objcopy 2.32 I get the following file headers which seems to me like it is
using the --output-target flag instead of --binary-architecture:

File: embedfs_minimal-cheri128-disk.o
Format: ELF64-mips
Arch: mips64
AddressSize: 64bit
LoadName: 
ElfHeader {
  Ident {
    Magic: (7F 45 4C 46)
    Class: 64-bit (0x2)
    DataEncoding: BigEndian (0x2)
    FileVersion: 1
    OS/ABI: SystemV (0x0)
    ABIVersion: 0
    Unused: (00 00 00 00 00 00 00)
  }
  Type: Relocatable (0x1)
  Machine: EM_MIPS (0x8)
  Version: 1
  Entry: 0x0
  ProgramHeaderOffset: 0x0
  SectionHeaderOffset: 0x38001A0
  Flags [ (0x0)
  ]
  HeaderSize: 64
  ProgramHeaderEntrySize: 0
  ProgramHeaderCount: 0
  SectionHeaderEntrySize: 64
  SectionHeaderCount: 5
  StringTableSectionIndex: 4
}</pre>
        </div>
      </p>


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