[CentOS-devel] CentOS 5 PowerPC port?

[Greg Snyder]

Hi Karanbir,

On Wed, May 26, 2010 at 01:34:19PM +0100, Karanbir Singh wrote:
> Hi Greg,
> 
> On 05/21/2010 03:55 PM, Greg Snyder wrote:
> > Can you please point me at where any scripts _do_ live?  Or a

Thanks for the overview.  I appreciate it.

> we use a hacked up verion of plage ( hacked up not in terms of 
> functionality, but in terms of how it works to make it work for the 
> environment we are using at the moment ). There is no bootstrap for i386 
> / x86_64 since those tree's build independently anyway. Much like ia64 
> and s390x. Ppc is interesting in this regard, its not really ppc, its 
> the ppc64 with some userland in ppc only code being churned out from a 
> dual target capable gcc. I highly recommend not messing around with any 
> buildsystem like plague or koji or anything such till such time as the 
> bootroots can be done using a scripted process.

Sure, I don't need to try to automate what I can't yet do.  :)

> So what we need to do is workout what it is that you want to be working 
> on. Based on your comments so far, and those from others - I dont think 
> there is any sort of conversation or through that has gone into this.

Yes, that's right.  I'm most interested in the userland side.  I'd like
to get a set of RPMs built that (initially) target something pretty
generic (-mcpu=common kind of thing) that can be used on a variety of
systems.  There's also the interesting and unfortunate question of soft
vs hard floating point, as I'm eventually hoping to run the result of
this on some non-fp systems.

I'd like to help with getting a suitable buildchain/buildroot setup for
this.  As for conversation, just let me know, and I'll be there.  I
don't yet have any strong ideas about how to get this done, and I'm
happy to talk.

> Ideally, we would like to have a ppc64 clean buildroot  + a ppc clean 
> buildroot, sharing the dual target capable gcc ( which would need an 
> infected ppc64 buildoot itself to build! ). And we would need a couple 
> of kernel build chains targeting the  scenarios that most people are 
> often confused by :
> - Target ibm power4+
> - Target Mac ppc64
> - Target Mac <= G4
> - Target legacy IBM power kit
> 
> We would then need to formulate the actual build plan.
> 
> Work that Tim Verhoeven and Fabian Arrotin have been doing, and things 
> that I've done in the past have been aimed at creating these build 
> chains. The actual decision on where the deliverable distro will target, 
> is sort of open still. I know that many of us would like to see Mac 
> hardware targeted, but we also want to get something usable, and binary 
> compatible with upstream so as to meet the CentOS mandate.

Where have you, Tim and Fabian got up to with the build chain and any
associated buildroot(s)?  Can you point me at what you have so far?  I'd
like to start helping out, and have some time during the next few weeks.

Yes, I'd like to see the Mac targeted as well.  From what you're saying
though, power4 would be the only strict requirement.

> For the sake of clarity - I take a buildroot to mean just that, a build 
> root - either setup and managed manually or using tools like mock. And a 
> buildchain to mean the process that would use one or more such 
> buildroots to arrive at he desired result. And yes, in many cases its a 
> one to one mapping. On platforms like i386 / x86_64 / ia64, its an 
> exclusive one to one mapping.But hey, ppc is interesting right ?

Okay, thanks.

If it makes sense to have a chat about all this, please let me know.

Thanks,
Greg