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From: =?UTF-8?B?5b6Q5oyB5oGSIFh1IENoaWhlbmc=?= <chiheng.xu@gmail.com>
Date: Fri, 18 Nov 2022 22:35:43 +0800
Message-ID: <CAPOVtOsG-of2t3am_w=mep-aev_R_NJWS2FtvBvC8qeqBju6iQ@mail.gmail.com>
Subject: Re: [PATCH] binutils: partially revert 17c6c3b99156fe82c1e637e1a5fd9f163ac788c8
To: Jan Beulich <jbeulich@suse.com>
Cc: "binutils@sourceware.org" <binutils@sourceware.org>, "H.J. Lu" <hjl.tools@gmail.com>
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On Fri, Nov 18, 2022 at 9:31 PM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 18.11.2022 11:45, =E5=BE=90=E6=8C=81=E6=81=92 Xu Chiheng wrote:
> > using x86_64-elf-g++ -m32 -c on C++ files to generate head.o(32 bit
> > code, elf32).
> > using x86_64-elf-objcopy to convert it to elf64.
> > then link head.o(32 bit code, elf64) with other object files(64 bit
> > code, elf64).
> >
> > link script line is :
> >   .head           : { head.o (.multiboot) head.o (.*) }
>
> Was that GNU objcopy you used? I've just tried here, and I don't see
> it converting from REL to RELA.
>

x86_64-elf-objcopy -I elf32-i386 -O elf64-x86-64
kern/core/x64/head/start32.cpp.o kern/core/x64/head/start32.cpp.o

How does binutils's objcopy convert ELF32(USE_REL) to ELF64(USE_RELA)?
How does it process relocation entry?
Right now, I'm not familiar with objcopy. I need to read the code.