Am 06.10.2011 um 22:29 schrieb Paulo César Pereira de Andrade paulo.cesar.pereira.de.andrade@gmail.com:
Em 6 de outubro de 2011 15:41, Jon Masters jcm@redhat.com escreveu:
On Thu, 2011-10-06 at 15:20 -0300, Paulo César Pereira de Andrade wrote:
Em 6 de outubro de 2011 14:38, Jon Masters jcm@redhat.com escreveu:
On Tue, 2011-10-04 at 00:41 -0300, Paulo César Pereira de Andrade wrote:
For now I have been only considering gcc as compiler
I think, realistically, so have we. But I'm open to rethinking that.
The problem is that this compiler apparently only offers two options, softfp (not softfp calling convention) by generating code without fpu support, and hardfp that only supports float arguments on float registers. IMO, the hardfp abi is not something for a distribution, but for a "closed" (not necessarily closed source) image, where the exact hardware is known before hand, and from Linux pretty much only the kernel and a few packages are used.
Yup. We disagree :)
I believe incompatible ABI changes are painful, but occasionally (very occasionally, and with some planning, co-ordination, justification, and a planned execution) can be necessary. The hard float ABI brings enough benefits that the various distributions are standardizing on it for v7. I would hope that we can all get behind this and treat v7 as a new architecture rather than simply an iteration, but I understand if you don't want to do that. Having said that, we do want to do that :)
I understand that the arm ecosystem is not like x86; imagine if suddenly distros did choose to use regparm=n, sseregparm=n, well most distros already expect i686/sse, but do not use sse due to abi constraints.
However, nobody compiles x86 binaries without tls support or for < i586 today anymore either. Armv7 seems like a nice time for a clean cut.
I think the point here is the "bring enough benefits" that we are not agreeing. Personally, what I am afraid is that who will decide this is not distros, but companies providing binary blobs (e.g. video drivers).
There are two pieces to the puzzle here:
1) binary video drivers
I don't want them. If you really have to support companies that don't want to work with us in reasonable ways, just put your X server in a chroot for whatever abi/environment they want and call it a day
2) binary application software
Right now there is none. Period. Maybe ARM will get enough market share one day to get ISVs to actually develop for ARM. By then they will check what distros use abi-wise and go with that. If that's hardfp then it's hardfp and everyone's happy.
Alex