OSLib and ELF

[David J. Ruck]

On 3 Feb 2007 Tony van der Hoff <tony at vanderhoff.org> wrote:
> On 3 Feb at 16:32 "David J. Ruck" <druck at druck.org.uk> wrote in message
> <2cbf71af4e.druck at druck.freeuk.net>
>> How much work would it be to generate an ELF version of OSLib as well as
>> an ALF?
>> 
>> GCC 4.1.1 is on its way with support for the ELF toolchain, and Firefox2
>> has already been built against it. To be useful in a wider context native
>> SWI support via OSLib is pretty essential.
>> 
> I've really no idea, Dave, as I don't know the ELF format. I guess I need
> to read up on precisely how different it is from ALF, and then make the
> necessary changes to the build scripts. I suspect the former is the most
> daunting, as I don't really know where to start. 

Well I assume that if Alan has managed to get it to build with the current
3.4.6r2 GCCSDK in ALF format, then using the 4.1.1 toolchain should kick out
an ELF object which could be directly linked against. Thats probably all we
require, I don't think a shared library is any benefit for OSLib.

> Learning ELF would probably be a useful project for me; does anyone have
> any good links to its omplementayion, other than the rather heavy-going TIS
> document? Google throws up some intriguing, though not entirely
> appropriate, links :(

It is rather heavy going, certainly a lot more to it than AOF/ALF. 
I used used the TIS primarily, suplimented by the much breifer ARM specific
http://www.arm.com/pdfs/DUI0101A_Elf.pdf plus to get some of the literal 
values arm.h from OpenSolaris of all places
http://src.opensolaris.org/source/xref/sfw/usr/src/cmd/gdb/gdb-6.3/include/elf/arm.h

>> I've added ELF executable and shared library format support to ARMalyser
>> if thats any help.
>> 
> It may help; frankly I'm out of my depth here.

Well it would show if there was anything stupid in an ELF file, but you'd
have to know what it all meant to check for it. You'd probably end up finding
all my misunderstandings of the format first though!

Cheers
---Dave

-- 
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  David J. Ruck    Phone: +44- (0)7974 108301    Email: druck at druck.org.uk
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