Taking this ecos-devel.
>>>>> "Simon" == simon [EMAIL PROTECTED] ch <[EMAIL PROTECTED]> writes:
Simon> Do you know if this patch also fixes debugging synth
Simon> binaries with gdb 6.8 on Debian/Ubuntu, which were compiled
Simon> with a new 4.x toolchain? I currently moved back to a
Simon> legacy gcc (3.2.1) for synth debugging, which of course is
Simon> very sub-optimal. I will get my own repo up to date once
Simon> you also merged flash v2, so I can test again.
As far as I am aware nobody is working on this.
I believe there are two issues re. Debian/Ubuntu:
1) their builds of gcc default to -fstack-protector, whereas other
distributions default to -fno-stack-protection. Supporting that option
requires extra work inside the synthetic target, including
manipulating segment registers, and the details are not well
understood. For example it is not clear whether that extra work would
need to be done only during initialization or for every context switch
(the synthetic target does not support a separate interrupt stack so
that at least is not a concern).
Ideally somebody would investigate this further and provide a suitable
patch for the synthetic target. I am not planning to work on this.
A workaround would be to add -fno-stack-protector to the default
build flags for the synthetic target, but that would break builds for
older distributions which don't recognise the flag. So we have a
choice: fix this problem for current Debian/Ubuntu users while
breaking things for people with old distributions (they would have to
edit the relevant config option to remove the flag); or keep things
working for people with old distributions while breaking things for
Debian/Ubuntu users. I have no strong feelings either way. It has been
quite some time since the problem was first noticed so there should be
a lot fewer people with older distributions.
2) some Debian/Ubuntu builds of gdb report an internal error, as per
http://sourceware.org/ml/ecos-discuss/2008-09/msg00045.html
This is not a bug in eCos, it is an internal error in gdb, although
it might be possible to avoid triggering the internal error by some
tweaking of the eCos code. As far as I know other Linux distributions
are not affected, and in particular I have not had any gdb problems
with the synthetic target under Fedora. So either:
a) the Debian/Ubuntu builds of gdb incorporate a dodgy patch, or
b) mainline gdb is broken, but Fedora and other distributions
incorporate a patch that fixes the problem.
So looking at the source packages for each distribution could help.
Actually figuring out exactly what in eCos causes the internal error
would also help. Either way this should really be fixed in the
Debian/Ubuntu world, not inside eCos. If somebody investigates further
and provides a harmless patch to the synthetic target which bypasses
the problem, that would be acceptable as well - but note the
"harmless".
Again I am not currently planning to work on this. Some
Debian/Ubuntu user needs to step up to the plate.
Bart
--
Bart Veer eCos Configuration Architect
eCosCentric Limited The eCos experts http://www.ecoscentric.com/
Barnwell House, Barnwell Drive, Cambridge, UK. Tel: +44 1223 245571
Registered in England and Wales: Reg No 4422071.
