Cross platform building best practices (building 6 on 7)
pisymbol at gmail.com
Fri Jun 20 21:24:14 UTC 2008
On Fri, Jun 20, 2008 at 5:14 PM, Julian Elischer <julian at elischer.org> wrote:
> Alexander Sack wrote:
>> On Thu, Jun 19, 2008 at 11:22 AM, Garrett Cooper <yanefbsd at gmail.com>
>>> On Thu, Jun 19, 2008 at 6:29 AM, Alexander Sack <pisymbol at gmail.com>
>>>> Hello Folks:
>>>> I've done a lot of Googling and scouring the lists about this
>>>> particular subject so I apologize for rehashing it. However, I'm
>>>> still confused on what's the best way to perform BSD cross platform
>>>> builds. Ideally what I want to have is an environment whereby I can
>>>> build a 6.1-RELEASE tree on a 7.0-RELEASE box. I thought originally I
>>>> could check out a 6.1 release version, perform make world, and then
>>>> use the output of that build as either a basis for a jail or a
>>>> toolchain. However, as noted by previous threads, 6.x doesn't build
>>>> on a 7.x due to gcc4/binutils compatibility issues (please correct me
>>>> if I'm wrong). I then thought I could potentially download a patched
>>>> binutils, copy it into src/contrib/binutils and that would potentially
>>>> fix it. No dice (and I'm still debugging why since this binutils
>>>> package DOES build outside of the make world infrastructure without
>>>> issue, this very well could be pilot error on my part since I didn't
>>>> update the VERSION string and didn't trim the source files as per the
>>>> FreeBSD-deleteList etc.).
>>>> I THEN thought if I build/install a gcc-3.x/bintuils toolchain I could
>>>> complie a 6.x on a 7.x machine. Well I haven't done that yet since at
>>>> this point I believe I'm diverged from the path of FreeBSD build
>>>> enlightenment! Moreover, if would be NICE if I could bootstrap the
>>>> normal dev tools from the exiting make world build tree. I'm not yet
>>>> ready for a lot of hackery on the build tree without asking around.
>>>> Does anyone due cross-platform builds (without host virtualization)?
>>> (I'll stick to just hackers@ because I don't want to pollute
>>> questions@ unnecessarily)
>> Sorry I felt really bad actually cc'ing questions its just that my
>> last groking produced many threads in freebsd-questions as opposed to
>> hackers. I'll try to be more attentive to my posts (I have a habit
>> cc'ing multiple forums because sometimes they apply but questions is
>> for normal troubleshooting, not cross-platform build issues!).
>>> You touched on an important point. There were some code quality issues
>>> (I think) with 6.x that were resolved moving to 7.x, which caused
>>> gcc-4.2.x to barf.
>> Probably but I'm not trying to point fingers! :D!
>>> gcc-4.2.x requires a newer version of binutils, just because (for API
>>> / usage compatibility).
>> Yea understood. To be honest, this isn't documented very readily. I
>> first thought it was pilot error on me, then I decided to take a look
>> at what failed to compile (I believe it was an innocent extern). And
>> then got lost in gcc/binutils hell. Luckily I've smelled this problem
>> before and after some research confirmed by suspicion.
>>> What you should probably do is create a jail then do your development
>>> for 6.x in a jail, 7.x in another, and (if you're bold enough ;)...)
>>> do 8.x development in yet a third. Jail's are a much better way to
>>> isolate things such that you don't have to worry about toolchain
>>> issues like these and are able to setup a sourcebase as the devs
>>> intended it (for the most part; you may run into issues with sysctls
>>> and virtual kernel stuff like that, but cest la vie... there isn't a
>>> better way I know of than that outside of running a VM).
>> I figured you were going ot say that Garrett. Well OK, but I still
>> need to bootstrap my dev environment for 6.x development on 7.x.
>> Since binutils compatibility makes my 6.x make world barf on 7.x,
>> where should I go? I HAVE not parsed through a lot of the build
>> infrastructure yet but it would seem to be IF make world bootstraps
>> the world including the development tools, why can't I update
>> binutils/gcc inplace and then compile (or is this a regression issue
>> which I failed to grasp). Or do I need to update binutils on my
>> *host* system itself? i.e. what I'm really asking is does make world
>> bootstrap the right bintuils/gcc etc. and then use THAT to compile the
>> rest or does it just perform a host build of everything and plops it
>> in DESTDIR?
>> Hope I make some sense here (still a n00b)....
> One thing we always strive for in FreeBSD is an upgrade path.
> As a general rule, a newer system should be able to run a jail
> populated with an earlier system. There are some small exceptions,
> for example you may need a new version of netstat, ps and libkvm
> in your jail. possibly grab them from the /rescue on the new system
> so they are statically linked.
> also 8.x systems will require that threaded programs from 6.x be dynamically
> linked so that they can be remapped to use libthr instead of libkse as
> libkse is not supported in 8.
So you are talking about binary/ABI compatibility yes? So I would
assume what you are saying is I can take a 6.x system, create a
filesystem tarball, drop it on a 7.x system and then create a jail out
> asside from those I think that just about every thing else should be fine..
> I've run a FreeBSD 1.1 chroot on a freeBSD 7 system
> (I had to make 1 very small fix).
> At Ironport we build 4.x binaries on 6.x systems by spinning off
> a 4.x chroot as prart of the build process. (they need to link with 4.x
> third party binaries) so it's very esay to do.
I believe this answers my question but I want to confirm. I THOUGHT
about this but I wanted a more *cleanroom* approach. That's all.
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