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Date: Sun, 30 Jul 2017 18:42:31 -0300
From: Eduardo Habkost <ehabkost@redhat.com>
Message-ID: <20170730214231.GC16400@localhost.localdomain>
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Subject: Re: [Qemu-devel] How to make ELF headers/symbol sections available
 for multiboot?
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To: Anatol Pomozov <anatol.pomozov@gmail.com>
Cc: qemu-devel@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <rth@twiddle.net>, Alexander Graf <agraf@suse.de>, Kevin Wolf <kwolf@redhat.com>


CCing Alex, the original author of load_multiboot(), and Kevin,
who touched multiboot code recently.


On Fri, Jul 28, 2017 at 02:28:34PM -0700, Anatol Pomozov wrote:
> Hi
> 
> I am looking at x86 multiboot code and trying to add "ELF section
> header" info feature. This will let target to learn more about booted
> binary and its sections.

Are there existing OSes that use that information?


> 
> I have a draft here
> https://github.com/anatol/qemu/commit/ad943a6eb78feee048b6bb2a1e5f49f5b686e24c
> 
> My understanding is that qemu multiboot loads only TEXT/BSS/DATA
> sections. Other stuff like symbols sections and ELF headers are not
> available for target.
> 
> So I need to perform 2 things:
> 
>  - Load ELF section headers into target's memory. I did by appending
> additional space to mbs.mb_buf and copying header data. Is it the best
> way to do?
> 
>  - Next I need to load other ELF sections such as symbols (e.g.
> .shstrtab) that store section names. What is the best way to do in
> multiboo.c code? Would it make sense to load all ELF sections?
> 
> Thanks in advance.
> 

-- 
Eduardo