[coreboot] Now Proposal for cross-compiler Re: Simnow & payloads (Was: something else)
Marc.Karasek at Sun.COM
Fri May 16 14:51:04 CEST 2008
Jordan, et all,
There is one caveat to my previous email.
Currently for LAB busybox is compiled with uClibc using the -nostdlib
option. According to the uClibc FAQ is no longer supported (since
0.22). It was handled through a toolchain wrapper and the uClibc guys
decided that it was too much of a problem in maintaining it and pulled
the support. They now recommend building a toolchain with buildroot and
using this to compile your application/program.
mailto:marc.karasek at sun.com
Marc Karasek wrote:
> I agree with you about it being more of a coreboot problem than a
> toolchain problem. (Although, building a cross-compiler is really quite
> simple, if you use the crosstools scripts. It is just a matter of
> running a script.) I will put together all of my information on what is
> broken and what errors I am seeing as soon as I can.
> I know that (recently) gcc/binutils has been through a "tightening"
> process where they have been trying to cleanup their act, by following
> more strict compiling/linking. This has resulted in quite a few builds
> being broken due to things that were once allowed and are not allowed now.
> I like the idea of being able to "specify" a local toolchain. This would
> give someone the option to compile and build with a "known" good
> toolchain. I feel this is useful in that toolchain problems can be very
> difficult to track down. They normally manifest themselves in a seg
> fault when running the compiled application or a very ambiguous error
> message during linking/compiling. This would provide a path for someone
> to continue on with their development/testing while (potentialy) someone
> else looks at the build problem.
> I will look at this and see what changes would need to be made to
> buildrom to make so you can specify a different local compiler. This
> would follow along the lines of $(CROSS-COMPILER) macro that is usually
> used for compiling an application with a cross-compiler.
> Marc Karasek
> Sun Microsystems
> mailto:marc.karasek at sun.com
> Jordan Crouse wrote:
>> On 14/05/08 10:58 -0400, Marc Karasek wrote:
>>> Jordan, Marc, Ron, et all.
>>> I found the problem with building coreboot-v2. It was the binutils. I
>>> believe the seg fault in linking tint/coreinfo is the same issue. I will
>>> try to verify this soon.
>>> I would like to propose that we move to a cross-compile type of
>>> environment. We could use crosstools scripts to build a complete
>>> environment that would go under /opt/crosstools. This could then be used by
>>> buildrom to build with. The advantage is that everyone will be on the same
>>> page in terms of gcc/binutils/glibc versions and we can have a better
>>> control over what tools
>>> are used. It gets us away from any distro/tools dependencies. It will
>>> also let us test new toolchains in a very controlled environment. Another
>>> added bonus with a common set of tools is that third-party developers
>>> can use this without worrying about toolchain issues.
>>> I have some experience in using cross-compilers from other embedded
>>> projects. I have already setup crosstools with gcc 4.1.0 / binutils 2.16 /
>>> glibc 2.3.6 on my system. I could take on the task of modifying buildrom
>>> to use this toolchain instead of the "native" toolchain. I
>> I feel very strongly that this should not be mandatory. I appreciate
>> the trouble you have had, but I think that adding a mandatory cross-compile
>> toolchain is too high a barrier for entry for novice buildrom users.
>> I have always believed, and I will always believe that the reason that
>> any given toolchain doesn't work out of the box is the fault of the software
>> you are compiling and not the fault of the toolchain. The moment we start
>> to turn a blind eye to our own faults and start blaming toolchains, then we
>> have started down a slippery slope. Eventually, coreboot and buildrom and
>> the payloads will only be compilable with a special toolchain that is six
>> years old and we'll be content to sit around and blame it all on the compiler
>> team. Thats not a future I relish.
>> If libpayload based payloads are not building, then I consider that a
>> personal failure, and we need to resolve it. Please send me the details.
>> That all said, I would be perfectly happy to let the user specify a
>> local toolchain to compile buildrom, as long as that behavior is configurable
>> and the default remains to use the system toolchain. I'm sure that your
>> experience with crosstools will be good for a wiki page describing the
>> care and feeding of a cross-compile toolchain and how to use it with
>> buildrom. I look forward to seeing that.
>> But I beg you, please give us as much information as you have about your
>> failures so that we can try to fix them in the code. And everybody else,
>> we need to stop throwing our hands up when we encounter toolchain issues -
>> we need to understand them and why there is a much better then average
>> chance that it is our code that is to blame.
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