GNU Binutils' Binary File Descriptor library - format example

Question

As in title. I tried reading the BFD's ELF's code, but it's rather not a light reading. I also tried to get something from the documentation, but I would need an example to see how it works. Could anyone point me some easier example for me, to know how to define an executable format?

Edit: Looks like I didn't formulate the question properly. I don't ask "how to create own executable format specification?", nor "where is good ELF documentation?", but "how can I implement my own executable format using GNU BFD?".

Your question now makes less sense, not more..... can you expand on that some more? — Mahmoud Al-Qudsi, Oct 01 '11 at 01:33
I want to be able to compile my programs using GNU toolchain, but executable should be generated in format defined by me. — Griwes, Oct 01 '11 at 07:16

score 4 · Accepted Answer · answered Oct 02 '11 at 10:26

You did look here http://sourceware.org/binutils/docs-2.21/bfd/index.html and here http://sourceware.org/binutils/binutils-porting-guide.txt?

Also studying the MMO implementation of a BFD backend as mentioned here http://sourceware.org/binutils/docs-2.21/bfd/mmo.html#mmo (source: http://sourceware.org/cgi-bin/cvsweb.cgi/src/bfd/mmo.c?cvsroot=src) might be less complex than starting with ELF ... ;-)

score 2 · Answer 2 · answered Sep 30 '11 at 13:43

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I agree that BFD documentation is somewhat lacking. Here are some better sources:

ELF Format
System V ABI (section 4)

Here are a couple of readable introductions:

And some examples that don't use libbfd:

answered Sep 30 '11 at 13:43

Seth

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Hmm, I think I must reformulate my question. I don't ask "how to create own executable format specification", nor "where is good ELF documentation", but "how can I implement my own executable format using GNU BFD". – Griwes Sep 30 '11 at 13:59

score 1 · Answer 3 · answered Sep 22 '11 at 21:19

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The DOS COM file is the simplest possible format.

Load up to 64k less 256 bytes at seg:0100h, set DS,ES,SS=seg, SP=FFFFh and jump to seg:0100h

answered Sep 22 '11 at 21:19

Joshua

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Hmm, but the binutils' msdos format lack some features... and as most gnu code, lack almost any documentation - assuming I should always know what is going on, when reading the code. – Griwes Sep 22 '11 at 21:36

GNU Binutils' Binary File Descriptor library - format example

3 Answers3