[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) forma
From: |
Paul Brook |
Subject: |
Re: [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) format |
Date: |
Thu, 9 Feb 2012 13:36:35 +0000 |
User-agent: |
KMail/1.13.7 (Linux/3.1.0-1-amd64; KDE/4.6.5; x86_64; ; ) |
> Paul Brook <address@hidden> writes:
> >> > starting your own toy kernel is a fun thing to do and there are many
> >> > tutorials out there on how to do it. Unfortunately when one wants to
> >> > write a kernel in 64bit it becomes much harder because one can't
> >> > compile 64bit code as elf32 image and converting a elf64 image to
> >> > elf32 format is a major hassle and looses debug information and
> >> > symbols.
> >
> > So just have two versions of your image:
> > - The elf64 image that has debug info, symbols, etc. Point gdb at this.
> > - An elf32 image that you give to the bootloader (in this case kvm)
> >
> > Generating the latter from the former is a trivial objcopy invocation.
>
> Is it? I tried for a while and couldn't figure it out. I checked how
> linux does it and it does quite a dance to achieve it.
"objcopy -I elf64-x86-64 -O elf32-i386 64.elf 32.elf" worked for me.
Relocations get a bit confused, but you shouldn't have relocations in your
multiboot images to start with.
Linux is a bit special because it has its own boot protocol. AFAIK it can't be
used as a regular multiboot image directly, you need to add a wrapper (i.e. a
secondary bootloader).
Paul
- [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) format, Goswin von Brederlow, 2012/02/04
- Re: [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) format, Stefan Hajnoczi, 2012/02/06
- Re: [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) format, Goswin von Brederlow, 2012/02/08
- Re: [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) format, Kevin Wolf, 2012/02/08
- Re: [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) format, Stefan Hajnoczi, 2012/02/08
- Re: [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) format, Paul Brook, 2012/02/08
- Re: [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) format, Goswin von Brederlow, 2012/02/09
- Re: [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) format,
Paul Brook <=
- Re: [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) format, Goswin von Brederlow, 2012/02/09
- Re: [Qemu-devel] Support for multiboot images in elf64 (EM_X86_64) format, Paul Brook, 2012/02/09